Impco Engine Catalog 2008

INDEX I. SAFETY ......................................................................................................................... 1 II. Carburetor/Mixer Overview ......................................................................................... 3 A. Air Valve Mixer Theory of Operation........................................................................ 3 B. Venturi Mixer Theory of Operation........................................................................... 3 C. Selecting the Correct Carburetor/Mixer ................................................................... 5 D. Formulas.................................................................................................................. 6 III. VARIFUEL Carburetor/Mixer Descriptions & Specifications .................................... 9 A. Model 400VF3 ....................................................................................................... 11 B. Model 600VF3 ....................................................................................................... 24 C. Model 600VF3D..................................................................................................... 39 IV. VARIFUEL Carburetor Installation............................................................................ 49 A. Model 400VF3 ....................................................................................................... 49 B. Model 600VF3 ....................................................................................................... 55 C. Model 600VF3D..................................................................................................... 63 V. VARIFUEL Carburetor Adjusting & Maintenance .................................................... 69 A. Adjusting the VARIFUEL Carburetor ..................................................................... 69 B. Lean Burn Operation ............................................................................................. 70 C. Changing the Gas Valve/Jet Kit ............................................................................. 72 D. Changing the Power Valve & Power Jet ................................................................ 80 E. Recommended Service Parts ................................................................................ 83 VI. Pressure Regulators .................................................................................................. 87 A. Introduction ............................................................................................................ 87 B. IMPCO IMP Regulators ......................................................................................... 91 C. Regulator Installation ............................................................................................. 95 D. Adjusting Primary and Sub-Regulators.................................................................. 97 VII. General Information ................................................................................................. 100 A. Gaseous Fuel Types............................................................................................ 100 B. Gaseous Fuel Benefits ........................................................................................ 100 C. Pressure Conversion Chart.................................................................................. 101 D. Crankcase Oil Requirements ............................................................................... 101 E. Effects of Temperature on Power Output ............................................................ 102 F. Effects of Altitude on Power Output ..................................................................... 103 G. Effects of Altitude on Manifold Depression (Vacuum).......................................... 104 H. Air Displacement by Fuel (& the Effect on Power Output) ................................... 105 I. Air- Terms and Measurement .............................................................................. 106 VIII.VARIFUEL Carburetor Application by Engine Manufacturer................................ 110 IX. Large Engine Application Information Worksheet ................................................ 113 X. Test Equipment/Tools.............................................................................................. 114 XI. Conversion Factors ................................................................................................. 117 XII. Approximate Heat Content of Petroleum Products............................................... 131 XIII.Correction Table for Altitudes................................................................................. 132 . Safety in the workplace is everyone’s responsibility.SAFETY READ BEFORE PERFORMING ANY SERVICE.org. read and understand all manufacturers’ recommended procedures.National Fuel Gas Codes NFPA #58. After working on any fuel system.LP Gas Storage NFPA #59. Before working on any fuel system. Avoid areas near flow drains or lubrication pits where escaped fuel man collect and all sources of ignition. There are state standards and regulations enforced by the state fire marshal in most states. 2007 . Before working on any fuel system. the Texas State Railroad Commission sets standards. turn OFF the fuel system supply valve and slowly bleed the fuel from all lines before working on the fuel system or engine. MAINTANENCE OR REPAIR ON THE FUEL SYSTEM There are safety regulations and standards that must be followed when installing or servicing gaseous fuel equipment on large engines.Combustion Engines NFPA #52. Natural gas is lighter than air and will rise to the highest point.CNG Vehicular Fuel Systems NFPA #54. it is very important that you pay attention to what you are doing for your safety and the safety of those around you. There may be other local standards set by counties. ©2007 IMPCO Technologies. Before working on any fuel system. study the NFPA standard for the fuel in use. and click on Document List and Code Cycle Information to order online. Inc. In Texas. cities and municipalities. perform a leak test before turning on the fuel valve. Before working on any fuel system. Avoid areas near overhead heaters and all other sources of ignition.nfpa. expand the Codes and Standards menu. gloves and clothing. Remember: • • LPG is heavier than air and will sink to the lowest level. face shields. make sure you have local code approved safety goggles. The following points are things to keep in mind when working on internal combustion engines and gaseous fuel systems: • • • • • • Before working on any fuel system. Be sure to consult all regulatory agencies to assure adherence to all standards in enforcement. contact the National Fire Protection Agency at (800) 344-3555 or go to www. Regardless of the type work you do. It is highly recommended you obtain and read the following National Fire Protection Association (NFPA) guidelines: • • • • • • NFPA #37. make sure there is adequate ventilation.LN Gas Storage and Handling To order these documents.LP Gas Utility Plants NFPA #59A. 1 June. 2007 .Throttle Closed Throttle Open ©2007 IMPCO Technologies. 2 June. Inc. The tapered shape of the gas-metering valve is designed to maintain the correct air/fuel ratio over the entire operating range of the engine. 2007 . Venturi Mixer During Operation ©2007 IMPCO Technologies. The metering spring is calibrated to generate about negative 6 inches (-6”) of water (H2O) column at idle and up to about -14” (H2O) column at wide open throttle. This negative pressure is used to draw fuel from the regulator into the intake air stream. The design of the venturi creates a slight negative pressure as air is drawn through it. Inc. Venturi Mixer Theory of Operation: The venturi mixer is a very simple design with no moving parts. As the diaphragm rises. Atmospheric pressure above the diaphragm forces it against the secondary metering spring opening the secondary valve allowing fuel to flow into the air/gas valve mixer. 3 June. It is placed in the intake air stream between the air cleaner and the throttle body. Atmospheric pressure acting on the under side of the diaphragm forces it upward against the metering spring. The amount of negative pressure generated is a direct result of throttle position and the amount of air flowing through the mixer. This negative pressure signal is communicated to the upper side of the diaphragm through passages in the air/gas valve assembly. Air Valve Mixer Theory of Operation: The air/gas valve mixer is mounted in the intake air stream above the throttle plate and is designed to create a slight pressure drop (negative pressure) as air is drawn into the engine. This allows the negative pressure signal to travel to the secondary chamber of the pressure regulator and act upon the under side of the secondary diaphragm. B. it lifts the tapered gas metering valve off of its seat and exposes the fuel outlet to the negative pressure generated within the mixer.Carburetor/Mixer Overview A. 0 x 61.04 CID Estimated Engine Airflow Requirements by CID and Maximum rpm (in CFM) ©2007 IMPCO Technologies.02. Example : 2. multiply the Liter Displacement by 61.ENGINE RPM (REVOLUTIONS PER MINUTE) CID 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250 400 5 10 15 20 25 30 34 39 44 49 54 59 64 69 74 79 84 89 93 98 103 108 113 118 123 600 7 14 22 30 37 44 52 59 66 74 81 89 96 103 111 118 125 133 140 148 155 162 170 177 184 192 199 207 214 221 229 236 243 251 258 266 273 280 288 295 303 310 317 325 332 339 347 354 362 369 376 384 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 10 20 30 39 49 59 69 79 89 98 108 118 128 138 148 157 167 177 187 197 207 216 226 236 246 256 266 275 285 295 305 315 325 334 344 354 364 374 384 394 403 413 423 433 443 453 462 472 482 492 502 512 12 25 37 49 61 74 86 98 111 123 135 148 160 172 184 197 209 221 234 246 258 271 283 295 307 320 332 344 357 369 381 394 406 418 430 443 455 467 480 492 504 516 529 541 553 566 578 590 603 615 627 639 15 30 44 59 74 89 103 118 133 148 162 177 192 207 221 236 251 266 280 295 310 325 339 354 369 384 398 413 428 443 457 472 487 502 516 531 546 561 576 590 605 620 635 649 664 679 694 708 723 738 753 767 17 34 52 69 86 103 121 138 155 172 189 207 224 241 258 275 293 310 327 344 362 379 396 413 430 448 20 39 59 79 98 118 138 157 177 197 216 236 256 275 295 315 334 354 374 394 413 433 453 472 492 512 22 44 66 89 111 133 155 177 199 221 243 266 288 310 332 354 376 398 421 443 465 487 509 531 553 576 25 49 74 98 123 148 172 197 221 246 271 295 320 344 369 394 418 443 467 492 516 541 566 590 615 639 27 54 81 108 135 162 189 216 243 271 298 325 352 379 406 433 460 487 514 541 568 595 622 649 676 30 59 89 118 148 177 207 236 266 295 325 354 384 413 443 472 502 531 561 590 620 649 679 708 32 64 96 128 160 192 224 256 288 320 352 384 416 448 480 512 544 576 607 639 671 703 735 34 69 103 138 172 207 241 275 310 344 379 413 448 482 516 551 585 620 654 689 723 758 37 74 111 148 184 221 258 295 332 369 406 443 480 516 553 590 627 664 701 738 775 39 79 118 157 197 236 275 315 354 394 433 472 512 551 590 630 669 708 748 787 42 84 125 167 209 251 293 334 376 418 460 502 544 585 627 669 711 753 794 44 89 133 177 221 266 310 354 398 443 487 531 576 620 664 708 753 797 47 93 140 187 234 280 327 374 421 467 514 561 607 654 701 748 794 49 98 148 197 246 295 344 394 443 492 541 590 639 689 738 787 52 103 155 207 258 310 362 413 465 516 568 620 671 723 775 54 108 162 216 271 325 379 433 487 541 595 649 703 758 57 113 170 226 283 339 396 453 509 566 622 679 735 59 118 177 236 295 354 413 472 531 590 649 708 61 123 184 246 307 369 430 492 553 615 676 64 128 192 256 320 384 448 512 576 639 66 133 199 266 332 398 465 531 598 1300 128 1350 133 1400 138 1450 143 1500 148 1550 152 1600 157 1650 162 1700 167 1750 172 1800 177 1850 182 1900 187 1950 192 2000 197 2050 202 2100 207 2150 212 2200 216 2250 221 2300 226 2350 231 2400 236 2450 241 2500 246 2550 251 2600 256 465 531 598 482 551 499 571 516 590 534 610 551 630 568 649 585 669 603 689 620 708 637 728 654 748 671 767 689 787 706 807 723 826 740 846 758 866 775 885 792 905 809 925 826 944 844 964 861 984 878 1003 895 1023 Engine Airflow requirement listed on the chart are in Cubic Feet per Minute (CFM) at 85% volumetric efficiency for 4-cycle engine (double the CFM for 2-cycle engines). 4 June.02 = 122. To convert liters (L) to CID. 2007 . Inc. 000 VARIFUEL Mixer/Carburetor Engine Applications Wide Open Throttle @ 2" Manifold Depression ©2007 IMPCO Technologies. If a carburetor is not available that matches the engine’s airflow requirements. naturally aspirated 817 CID engine and a redline of 2. To find the estimated airflow requirement for the engine you are converting: • • • Locate the engine’s displacement (in CID) and maximum rpm on the chart. a carburetor that is too large for an engine will create problems with idle stability and inconsistent fuel mixtures. Determining Estimated Engine Airflow Requirements with the Chart (on Facing Page). especially at low speed. Model 400VF3 600VF3 600DVF3 Rated Horsepower (Naturally Aspirated) 320 540 1. the proper carburetor/mixer may be selected. Inc. If the carburetor/mixer specified is too small. Consider these options when determining your Carburetor/Mixer needs. 2007 .800 96. 5 June. under carburet for maximum efficiency.000 Cubic Feet/Minute (CFM) 500 960 1.000 rpm: The estimated required airflow for this engine is 418 CFM (rounding the CID up to 850). The chart gives engine airflow requirements for some common engine displacements at various maximum rpms. the airflow capacity of the carburetor should be reasonably close to the airflow requirement of the engine. As a general rule. 3) After the engine’s airflow requirements are determined. Draw a line across from the CID and down from the rpm. In general. The following table gives the horsepower and maximum airflow ratings for the VARIFUEL carburetors. 2) Example: An industrial stationary generator with a 4-cycle.C. and over-carburet for maximum power. then it is usually recommended to over-carburet than under-carburet (round the CID up).000 57. Conversely.600 Cubic Feet/Hour (CFH) 30. then the power output of the engine will be limited. Where the lines cross is the airflow requirements (in CFM) for that engine. Selecting the Correct Carburetor/Mixer: 1) Airflow Capacities: It is important to correctly size the airflow capacity of the IMPCO VARIFUEL conversion carburetor/mixer to the engine airflow requirement. For 2-cycle engines. then convert it by multiplying by 0. Determine the % increase in supplied air pressure.000: 817 × 2000 ÷ 1728 ÷ 2 × 0.7 PSI): 1 + ((boost pressure in PSI) ÷ 14. then convert it to CID by multiplying by 61. The following equation is performed to calculate the percentage (%) increase in supplied air pressure.02.7) CID × RPM ÷ 1728 ÷ 2 × 0. Divide this by 2 for a 4-cycle engine (a 4-cycle engine only has an intake cycle every other revolution).20 = 567 CFM ©2007 IMPCO Technologies. If the displacement is in liters (L). Inc. 4-cycle turbocharged engine with boost pressure of 6 PSI and a maximum rpm of 2. This pressure must be calculated into the equation. • • 5) Determine the engine’s CID from the identification plate or from the user’s manual.Formulas: 4) The first thing that needs to be done before any calculations can be performed. 6 June. For Naturally Aspirated Engines: CID × RPM ÷ 1728 ÷ 2 × 0. is to determine the engine’s displacement in cubic inches (Cubic Inch Displacement or CID) and its maximum rpm. To accomplish this: • • • Determine the boost pressure of the turbocharger in Pounds per Square Inch (PSI). Example: 817 CID.000: 817 × 2000 ÷ 1728 ÷ 2 × 0. including atmospheric pressure (at sea level is 14.7)) = 817 × 2000 ÷ 1728 ÷ 2 × 0.06102. 4-cycle carbureted engine with a maximum rpm of 2.85 × 1. • • • • Multiply the CID times the rpm.85 (85% volumetric efficiency) to get the engine’s airflow requirement. Omit this step if engine is a 2-cycle. Multiply by 0. Determine the engine’s maximum rpm either by locating it on the tachometer (if equipped) or from the user’s manual.85 = Airflow Requirement (CFM) The engine airflow requirements determined by this equation are for 4-cycle engines with 85% volumetric efficiency.85 × (% available pressure increase) = CFM Example: 817 CID. omit the division by 2. If it is in cubic centimeters (CC). 2007 .85 × (1 + (6 ÷ 14.85 = 402 CFM 3) Turbocharged Engines (with mixer upstream of turbocharger): Turbocharged engines supply an additional boost in pressure over a naturally aspirated engine. Divide the result by 1728 to convert the cubic inches per minute (CIM) to CFM. 7 June. 2007 .©2007 IMPCO Technologies. Inc. 2007 . 8 June. Inc.VARIFUEL 400VF3 Carburetor ©2007 IMPCO Technologies. ....... Buna N............................................................................................ N/A (Engine User/Producer Responsibility) Weight 7...... Aluminum (Hard Anodized)...... 320o F Materials: Air Valve body (BB1-66)............................................................................................................................. N/A (Engine User/Producer Responsibility) Emissions Certification .......500 CFM @ 2” HG Depression (T2-7 @ WOT) Horsepower Rating .......................................................... Stainless Steel (optional) Power Valve .............................................. Zinc plated and baked Springs ..Aluminum (Hard Anodized) Throttle Body (T2-7 or T2-8) ................................................................. ©2007 IMPCO Technologies............................ Power Screw (10+ Turns) Temperature Limits: Max.......................... See Gas Valve Chart on page 31 Air/Fuel Adjustments: Low Speed/Load ..........................................Aluminum (Hard Anodized) Gas Body (B1-67) ....................................................Silicone over Fiberglass Guide Bushings........................................................................................................................................................... 75 PSI Backfire................................................................................................. Maximum ....................... Inc............................. Carbon Steel................................... Zinc plated and baked Lubrication .............................................................. 9 June.....Aluminum (Hard Anodized) Diaphragm (D1-25) ..................................................................Aluminum (Hard Anodized) Air Valve Cover (C1-30) ..................................................... PPS Plastic............................................................. 2007 ........................................................................................................................ Regulator Pressure (External to Carburetor) High Load.......... Fluorocarbon optional Fasteners & Power Screw...... Peak ........................... Glass and PTFE-filled Gas Valve............55 lbs (w/AT2-7 Throttle Body) (1) (2) Each fuel requires a unique gas valve and jet combination..................................................... 200 PSI Airflow Capacity ..................VARIFUEL Carburetor Descriptions & Specifications Model 400VF3 Specifications Fuel Type(1) ................................... 250o F Max.......................................................................................................................................... High Carbon Steel..................................................................................................................................... Normal .......................................................Aluminum (Hard Anodized) Inlet Housing (A2-70 or A2-69) ..........................................................................................................................320 BHP (Naturally Aspirated) Air/Fuel Ratios ................................. Requires J1-48 oversize power jet......................................................................................................................................... Operating.......Aluminum (Hard Anodized) Air Valve (V1-16)............................................ High Carbon Steel O-ring Seals ............... 5” H2O over Air Inlet (idle setting) Air Inlet..............................................................................................None Required Safety Certification............................. Soakback.................................. Propane & LPG (50/50 Propane/Butane) Natural Gas (85%+ Methane) Digester Gas (56-72% Methane)(2) Landfill Gas (45-56% Methane)(2) Operating Pressures: Gas Inlet..........................................Aluminum (Hard Anodized) Gas Jet.................................................. 400VF3 Modules ©2007 IMPCO Technologies. 2007 . Inc. 10 June. ) The attachment of the Air Inlet Module to the Gas Inlet Module uses a square bolt pattern. Both are designed for a 4.A. a unique module is available. Inc. 11 June. shape of the gas metering valve. It is designed to be a direct replacement for the IMPCO 200D carburetor. air valve type.0” diameter inlet hose. part # AA2-69. The 400 VARIFUEL is comprised of 5 modular elements (illustration on facing page): 1) 2) 3) 4) 5) Air Inlet Module (Air Horn) Mixer Module Gas Valve/Jet Module Gas Inlet Module Mixture Outlet Module (Throttle Body) A complete carburetor includes all five modules. For in-line flow applications. 2007 . Model 400VF3: The IMPCO 400 VARIFUEL (400VF3) is a gaseous fuel carburetor of the concentric flow. allowing four position options for the air inlet on the 90o inlet housing (part # AA2-70). and the pressure from the gas regulator. The air/fuel ratio is controlled by the adjustable power valve. ©2007 IMPCO Technologies. Deletion of either the Air Inlet or Mixture Outlet Module yields a mixer assembly. A precision gas metering valve is attached to the air valve. (See Ordering Information for part numbers. The 400VF3 has anti-wear guide bushings for the air valve assembly. The air valve (and gas valve) motion is linear in relation to volumetric flow. Inc. dictated by the Air Valve Vacuum (AVV) generated downstream of the mixer. The spring load and weight of the air valve/diaphragm assembly determines this motion. 2007 .Starting is largely controlled by the initial motion of the air valve. Interchangeable air valve spring spacers address updraft or sidedraft installations. ©2007 IMPCO Technologies. 12 June. 50” and ∅3. Two throttle bore sizes are available: ∅2.The gas valve and matching jet are sized for the gas to be used. The power valve has little influence during starting or under light loads. The mixture adjustment power valve is located in the Gas Inlet Module. Governor stability can be a problem if too large a throttle is used. Two versions of the Gas Inlet Module are available to address the widely varying energy densities of fuels used in stationary gaseous fueled engines such as digester. or landfill gases. ©2007 IMPCO Technologies. The power valve (attached to the mixture screw) is positioned within the power jet ID to provide an adjustable restriction to gas flow. The gas valve shape is most crucial in the low flow (starting and light load) operating conditions. Also. Inc. The attachment of the Gas Inlet Module also uses a square bolt pattern. Several jet sizes are available to adapt to fuels from propane to landfill gas. A variety of adapters are available to mount the 400VF3 upstream of a turbocharger. Gas valves are shaped to provide A/F versus flow characteristics defined by the customer. This can save valuable engineering time when developing low speed options. an adapter is available to mount 400 VARIFUEL mixers on 600 VARIFUEL gas inlet modules (A3-128). 13 June. remote from the throttle body.00”. allowing four position options for the gas inlet piping. 2007 . V2-88 is designed to be rich enough for proper control even under the coldest air inlet temperatures.400VF3 ACCESSORIES & OPTIONS IMPCO 400VF3 VARIFUEL Gas Valve Options: The 400VF3 VARIFUEL is designed to operate with a wide variety of fuels. The two largest jets are CNC machined from stainless steel to operate in the often corrosive environments of digester and landfill gases.4-1. Contact your local IMPCO distributor for more information. four gas metering jet sizes were developed with IDs of: ∅0. 14 June. This valve can run richer or leaner by adjusting the power screw. Inc. To do this. ∅0. The EB operates at -1. From high energy propane/butane mixes down to 420 BTU/ft3 landfill/digester gases.85-0. Six basic gas valves are available for specific fuels and emissions control strategies. the 400VF3 can mix them in a manageable manner.625”. The UL kit part number is CKV2-78. Natural Gas (FR) Catalytic/Feedback/Rich (λ=0. Stoichiometric (λ=1. These gas valves are generally only useable with turbocharged engines. 2007 . A good initial setting for the power screw is 6 turns from full lean (all the way in).6 (7. The NG conversion kit can be purchased under part number CKV2-77.5% O2) above air flows appropriate for 80 horsepower.900” and ∅1. V2-77 can also be used for propane operation with the IMPCO EB converter. but the A/F curve will be quite skewed and governor fluctuation can result.98) The FR gas valve kit part number is CKV2-88 and utilizes the V2-88 gas valve and J1-45 gas jet. The power screw can adjust the A/F within this range. NOTE: Gas valves for specific OEM applications are available. Natural Gas (UL) Ultralean (λ=1.6) V2-78 gas valve is used with J1-44 gas jet. Natural Gas (NG) Non-emissions. ©2007 IMPCO Technologies. These units place a control valve upstream of the carburetor in the fuel inlet.0) V2-77 gas valve is used with J1-45 gas jet.5 to 8. the gas inlet pressure should be set at 5-6” H2O column. Partial throttle operation on 100 to 250 HP engines will also be slightly lean. The A/F can be set from lean to stoichiometric with the power screw for economic operation.5” H2O carburetor inlet pressure.4-1. ∅0. since ultralean operation on normally aspirated engines results in 1/4 to 1/3 power loss.750”. These valves are easily interchangeable with a flat blade screwdriver.2) and transitions to λ of 1. For all 400VF3 gas valves.080” (these jets are completely interchangeable). This gas valve starts lean of stoichiometric (approximately λ of 1. This combination is designed to operate with throttling type A/F ratio controllers such as the Altronic units. 85-.0” H20). GAS VALVE V2-77 V2-78 V2-79 GAS JET J1-45 J1-44 GAS Natural Gas(2) BTU/ft3 (1) 800-1000 APPLICATION Non-emissions. Stoichiometric (λ=1. The LF gas valve is designed for a nominal gas energy of 480 BTU/ft3 with methane and CO2 as the primary constituents. These controllers either increase gas pressure at the regulator or add fuel between the carburetor and throttle body. With a higher pressure (8. LF requires the larger J1-48 power jet. The DG configuration requires the larger J1-48 power jet.2) The LF kit (part number CKV2-80) is comprised of the V2-80 gas valve and the stainless steel J1-47 gas jet. Like DG.3) J1-46 J1-45 Natural Gas Natural Gas(2) Lower heating value.98) 800-1000 Enrichment Feedback (λ=1. This combination is designed to operate with enrichment type air/fuel ratio controllers.4-1. 400VF3 carburetors with the DG prefix are already fitted with this power jet. This kit uses the V2-79 gas valve and the stainless steel J1-47 gas jet. Landfill Gas (LF) 420-540 BTU/ft3. 15 June. Stoichiometric (λ=1. This valve is designed for a nominal gas energy level of 600 BTU/ft3 with the gas constituents primarily methane and CO2.3) The FB kit part number is CKV2-89 and uses the V2-89 gas valve and J1-45 gas jet. 2007 . Also useable with propane via the EB converter. The higher pressure addresses the starting on a weaker gas. Digester Gas (DG) 540-660 BTU/ft3.1) The DG kit part number is CKV2-79. this valve can be used with 450-480 BTU/ft3 landfill gas operating at lean burn air/fuel ratios for low emissions. The power screw can be set at 8-9 turns out from full lean for best full load operation.1-1.0-1.1-1. V289 should not be used in an uncontrolled application because of the potential for oil nitration at these A/F levels. The power screw can be set a 6 turns out for reasonable full load operation.6) Natural Gas Digester Gas 540-660 J1-47 V2-80 V2-88 V2-89 (1) (2) Stoichiometric Landfill Gas 420-540 Throttling Feedback (λ=. Inc. V2-89 can also be used with air addition lean-burn controllers such as the PSC system or for stoichiometric propane operation with the IMPCO EB converter. stoichiometric Ultralean (λ=1. 400VF3 carburetors with the LF prefix are already fitted with the J1-48 power jet.Natural Gas (FB) Catalytic/Feedback/Lean (λ=1. ©2007 IMPCO Technologies. 2007 . 0.00” bore. throttling feedback. shaft.50” bore. Module Group I (Air Inlet): AA2-70: AA2-69: 90o.88” bolt pattern. fly. Inc. (540-640 BTU/ft3). stoichiometric w/J1-45 (also for Propane w/EB converter) (UL) Natural gas. jet. 400VF mixer to 600VF gas body Outlet adapter. (450-540 BTU/ft3).4). w/J1-47 (FR) Natural gas. One module from each of the module groups listed below is needed to make a complete carburetor. o-ring & label): CKV2-77: CKV2-78: CKV2-79: CKV2-80: CKV2-88: CKV2-89: (NG) Natural gas.4 to 1. Die cast. (λ=1. w/J1-46 (FB) Natural gas.05). 4. ∅ 2. 3.437” shaft Outlet adapter. gaskets & bolts): AB1-67: AB1-67-3: J1-36 Power jet. diaphragm. enrichment feedback.400VF3 ORDERING INFORMATION 400VF3 Modular Assembly: Except for some specific engine applications. spring. 2. jet.00” hose connection. body. w/J1-45 Module Group IV (Gas Inlet--body.00” hose connection In-line.6). ∅3. (λ=0. ultralean (λ=1. 16 June. bearings. power screw.25” bolt pattern.080 ID (Digester and Landfill gas usage) Module Group V (Mixture Outlet--body.800 ID (Natural gas and LPG usage) J1-48 Power jet. 3. turbo compressor inlet mounting ©2007 IMPCO Technologies. w/J1-44 (DG) Digester gas.00” hose connection Module Group II (400VF3 Mixer--air valve.2-1.85-1. carburetors must be ordered as subassembly modules and assembled by the customer/distributor.437” shaft Throttle body assembly. screw. Refer to your distributor for specific engine application carburetor availability. Refer to the Accessories & Options for information on the Gas Valve Kits. B3-44 bushings. stoichiometric. B3-44 bushings. cover): AB1-66-3X: AB1-66-3S: AB1-66-3U: VF3 Downdraft (w/Anti-wear bushings) VF3 Sidedraft (w/Anti-wear bushings and S4-38 spring spacer) VF3 Updraft (w/Anti-wear bushings and S4-39 spring spacer) Module Group III (Gas Valve/Jet Kit--gas valve. 1. stoichiometric. 0. 4. Sand cast. lever & gaskets): AT2-7: AT2-8: AA3-128: A3-129: Throttle body assembly. w/J1-47 (LF) Landfill gas. 0. 2007 . Inc. 17 June.400VF3 Mixer Assembly (Exploded View) ©2007 IMPCO Technologies. Inc.400VF3 Carburetor Dimensions (w/Straight Air Inlet/AT2-7 Outlet Module) ©2007 IMPCO Technologies. 2007 . 18 June. 400VF3 Carburetor Dimensions (w/90o Air Inlet/AT2-7 Outlet Module) ©2007 IMPCO Technologies. Inc. 2007 . 19 June. 2007 .400VF3 Carburetor Dimensions (w/90o Air Inlet/AT2-8 Outlet Module) ©2007 IMPCO Technologies. 20 June. Inc. 21 June.400VF3 Mixer Dimensions ©2007 IMPCO Technologies. Inc. 2007 . Inc.400VF3 Mixer to 600VF3 Gas Body Adapter Dimensions ©2007 IMPCO Technologies. 2007 . 22 June. 2007 . 23 June.©2007 IMPCO Technologies. Inc. VARIFUEL 600VF3 Carburetor ©2007 IMPCO Technologies. 24 June. Inc. 2007 . .......................................................................... 250o F Max..................................... N/A (Engine User/Producer Responsibility) (1) (2) Each fuel requires a unique gas valve and jet combination.........540 BHP (Naturally Aspirated) Air/Fuel Ratios .................................................................................................................................................. 320o F Materials: Air Valve body (B1-30-6).............. Stainless Steel (optional) Power Valve .................... ©2007 IMPCO Technologies.................................................................................................................................................................................................................960 CFM @ 2” HG Depression (T2-17 @ WOT) Horsepower Rating ............. Requires AB1-31-3 (J1-33 oversize power jet and W1-63 power valve)...............................................Aluminum (Hard Anodized) Inlet Housing (A2-16 or A2-22) ...... Operating................................................................................................ High Carbon Steel (Optional) O-ring Seals ...................... PPS Plastic..... N/A (Engine User/Producer Responsibility) Emissions Certification .. Glass and PTFE-filled Gas Valve.... 25 June......................................................................................................................................................................................................................... 2007 ..........................Aluminum (Hard Anodized) Throttle Body (T2-17................................................... Zinc plated and baked Springs ................... Inc......................................................Aluminum (Hard Anodized) Gas Body (B1-31-2) ..............................................................................Aluminum (Hard Anodized) Air Valve Cover (C1-32) .............................................. Zinc plated and baked Lubrication ................................................ Fluorocarbon optional Fasteners & Power Screw..................... Peak .........................................Model 600VF3 Specifications Fuel Type(1) ............................................................................................................................................................ 60 PSI Airflow Capacity ........... Buna N............................................................................None Required Safety Certification........... High Carbon Steel............................................................................................................................................................................................ 5” H2O over Air Inlet (idle setting) Air Inlet.... Maximum ...................................................................................... See Gas Valve Chart on page 31 Air/Fuel Adjustments: Low Speed/Load ............... Aluminum (Hard Anodized)...... Regulator Pressure (External to Carburetor) High Load...............................Fluorosilicone Guide Bushings...... 30 PSI Backfire....................... Carbon Steel........................................................................................................ Propane & LPG (50/50 Propane/Butane) Natural Gas (85%+ Methane) Digester Gas (56-72% Methane)(2) Landfill Gas (45-56% Methane)(2) Operating Pressures: Gas Inlet.... Power Screw (10+ Turns) Temperature Limits: Max.....................................................................................................Aluminum (Hard Anodized) Gas Jet.........Aluminum (Hard Anodized) Air Valve (V1-17)....................... Normal ........... T2-67 or T2-80) ................Aluminum (Hard Anodized) Diaphragm (D1-20-3) ........... Aluminum (Hard Anodized).................................... Soakback........................... 2007 . Inc. 26 June.600VF3 Modules ©2007 IMPCO Technologies. Both the air and gas valve motions are linear in relation to volumetric flow. Inc. allowing four position options for the air inlet on the 90o inlet housing (A2-16). The attachment of the Air Inlet Module to the Gas Inlet Module uses a square bolt pattern. Gas valves are shaped to provide A/F ratio versus flow characteristics defined by the customer. A precision gas metering valve is attached to the air valve. the 600VF3 has a premium fluorosilicone diaphragm. It is designed to be a direct replacement for the IMPCO 200T and IMPCO 600 carburetors. and the pressure from the gas regulator. for enhanced temperature. The attachment of the Gas Inlet Module to the Mixture Outlet Module uses a bi-directional bolt pattern. Also. Several jet sizes are available to adapt to fuels from propane to landfill gas. Model 600VF3: The IMPCO VARIFUEL 600VF3 is a gaseous fuel carburetor of the concentric flow air valve type. 2007 . The 600VF3 is equipped with anti-wear bushings for the air valve assembly. allowing two position options for the gas inlet piping relative to the throttle shaft and its rotation.B. The 600VF3 is composed of five modular elements: 1) 2) 3) 4) 5) Air Inlet Module (Air Horn) Mixer Module Gas Valve/Jet Module Gas Inlet Module Mixture Outlet Module (Throttle Body) A complete carburetor consists of all five modules. shape of the gas metering valve. The gas valve and matching jet is sized for the gas to be used. 27 June. chemical and wear resistance. The air/fuel ratio is controlled by the adjustable power valve. ©2007 IMPCO Technologies. Deletion of either the Air Inlet or Mixture Outlet Module yields a mixer assembly. sidedraft and downdraft versions are available for the 600VF3 Mixer Module.Updraft. Starting is largely controlled by the initial motion of the air valve. which is dictated by the vacuum generated downstream of the mixer. The spring load and weight of the air valve/diaphragm assembly determine this motion. Downdraft Updraft ©2007 IMPCO Technologies. Three air valve springs are available depending on installation requirements. Inc. 28 June. 2007 . Governor stability can be a problem if too large a throttle is used. 2007 . 29 June. Two versions of the Gas Inlet Module are available to address the widely varying energy densities of fuels. Inc. or landfill gases. remote from the throttle body. AB1-31-2 is used for propane. T2-80 has a shorter height to allow retrofitting IMPCO 200T’s directly with the 600VF3 with only a gas line repositioning. Several jet sizes are available to adapt to fuels from propane to landfill gas. Gas valves are shaped to provide A/F versus flow characteristics defined by the customer. Two throttle bores are available: ∅3.The gas valve and matching jet are sized for the gas to be used.69” and ∅4. The smaller bore should always be the first choice. A larger power jet and smaller power valve are used in the AB1-31-3 module to allow higher volumetric gas flow rates. AB1-31-3 is used for low energy density fuels such as digester. An adaptor is available to mount the 600VF3 upstream of a turbo compressor. The gas valve shape is most crucial in the low flow (starting and light load) operating conditions.19”. LPG and natural gas. ©2007 IMPCO Technologies. 400” (these jets are completely interchangeable). A good initial setting for the power screw is 6 turns from full lean (all the way in). The UL kit part number is CKV2-63. Natural Gas (UL) Ultralean (λ=1.00) The FR gas valve kit part number is CKV2-94 and utilizes the V2-94 gas valve and J1-24 gas jet. This combination is designed to operate with throttling type air/fuel ratio controllers. These gas valves are generally only useable with turbocharged engines. Contact your local IMPCO distributor for more information.6) V2-63 gas valve is used with J1-23 gas jet.5” H2O carburetor inlet pressure. the gas inlet pressure should be set at 5-6” H2O column. since ultralean operation on normally aspirated engines will result in a power loss. 30 June. Inc.600VF3 ACCESSORIES & OPTIONS IMPCO 600VF3 VARIFUEL Gas Valve Options: The 600VF3 VARIFUEL is designed to operate with a wide variety of fuels. From high energy propane/butane mixes to 420 BTU/ft3 landfill gases. The A/F can be set from lean to stoichiometric with the power screw for economic operation. Natural Gas (NG) Non-emissions. These units place a control valve upstream of the carburetor in the fuel inlet.5 to 8. ©2007 IMPCO Technologies. the 600VF3 can mix them in a manageable manner.4-1. Unlike old non-VARIFUEL units. ∅1. Partial throttle operation on 200 to 450 HP engines will also be slightly lean. Natural Gas (FR) Catalytic/Feedback/Rich (λ=0.2 λ) and transitions to λ of 1.6 (7. NOTE: Gas valves for specific OEM applications are available.0) V2-21-3 gas valve is used with J1-23 gas jet. V2-21-3 can also be used for propane operation with the IMPCO EB converter. V2-94 is designed to be rich enough for proper control even under the coldest air inlet temperatures. For all 600VF3 gas valves.0” H2O) gas pressure or excessive richness and misfiring might occur at light loads. The EB operates at 1. These valves are easily interchangeable with a flat blade screwdriver. 2007 . Stoichiometric (λ=1. ∅1.85-1. The two largest jets are CNC machined from stainless steel to operate in the often corrosive environments of digester and landfill gases. this valve should be run at lower (5. Six basic gas valves are available for specific fuels and emissions control strategies.4-1. The power screw can adjust the A/F within this range. This valve can run richer or leaner by adjusting the power screw. To do this.5% O2) above air flows appropriate for 200 horsepower.0-7. five gas metering jet sizes were developed with IDs of ∅0.000”.750”. The NG conversion kit can be purchased under part number CKV2-21-3. but the A/F curve will be quite skewed and governor fluctuation can result.250” and ∅1.125”. ∅1. This gas valve starts lean of stoichiometric (approximately 1. 1-1.Natural Gas (FB) Catalytic/Feedback/Lean (λ=1.98) Enrichment Feedback (λ =1.3) Natural Gas Digester Gas 540-660 Stoichiometric GAS Natural Gas (2) BTU/ft3 (1) 800-1000 APPLICATION Non-emissions.85-. this valve can be used with 450-480 BTU/ft3 landfill gas operating at lean burn air/fuel ratios for low emissions.0-1. This combination is designed to operate with enrichment type air/fuel ratio controllers.Lower heating value. The DG configuration requires the larger J1-33 power jet. 600VF3 carburetors with the LF prefix are already fitted with the J1-33 power jet. Landfill Gas (LF) 420-540 BTU/ft3. This kit uses the V2-64 gas valve and the stainless steel J1-25 gas jet.4-1. The power screw can be set at 8-9 turns out from full lean for best full load operation.1-1. Digester Gas (DG) 540-660 BTU/ft3. These controllers either increase gas pressure at the regulator or add fuel between the carburetor and throttle body. This valve is designed for a nominal gas energy level of 600 BTU/ft3 with the gas constituents primarily methane and CO2.1-1.Also useable with propane via the EB converter. LF requires the larger J1-33 power jet. With a higher pressure (8.3) The FB kit part number is CKV2-62 and uses the V2-62 gas valve and J1-22 gas jet. ©2007 IMPCO Technologies. 600VF3 carburetors with the DG prefix are already fitted with this power jet. Like DG.2) The LF kit (part number CKV2-65) is comprised of the V2-65 gas valve and the stainless steel J1-25 gas jet. Gas Valve Chart GAS VALVE GAS JET V2-21-3 J1-23 V2-63 V2-64 J1-25 V2-65 V2-94 V2-62 J1-24 J1-22 Landfill Gas Natural Gas Natural Gas(2) 800-1000 420-540 Throttling Feedback (λ =. The power screw can be set a 6 turns out for reasonable full load operation. Stoichiometric (λ=1.1) The DG kit part number is CKV2-64. (2). Inc. V2-62 can also be used with air addition lean-burn controllers or for stoichiometric propane operation with the IMPCO EB converter.6) (1). stoichiometric Ultralean (λ =1. The higher pressure addresses the starting on a weaker gas. The LF gas valve is designed for a nominal gas energy of 480 BTU/ft3 with methane and CO2 as the primary constituents. Stoichiometric (λ=1.0” H20). 2007 . V2-62 should not be used in an uncontrolled application because of the potential for oil nitration at these A/F levels. 31 June. fluorosilicone diaphragm (Turbo Drawthrough usage) Module Group III (Gas Valve/Jet Kit--gas valve. short piston. w/J1-25 Landfill gas. stoichiometric w/J1-23 (also for Propane w/EB converter) Natural gas. screw. stoichiometric. w/J1-23 Digester gas. cover): AB1-30-6: AB1-30-6H: AB1-30-6X: AB1-30-6S: AB1-30-6SL: Updraft. ∅6. Module Group I (Air Inlet): AA2-16: AA2-22: ∅6.4 to 1. throttling AFC for catalysts. ultralean (λ=1. 2007 .00” hose connection Module Group II (600VF3 Mixer--air valve. w/J1-24 Landfill gas. ultralean (540-640 BTU/ft3). S2-32-3 spring. stoichiometric. O-ring & label): CKV2-21-3: CKV2-62: CKV2-63: CKV2-64: CKV2-116: CKV2-65: CKV2-69: CKV2-94: CKV2-96: Natural gas. One module from each of the module groups listed below is needed to make a complete carburetor. S2-123 spring. diaphragm.600VF3 ORDERING INFORMATION 600VF3 Modular Assembly: Except for some specific OEM engine applications.) Module Group IV (Gas Inlet (body. spring.00”. w/J1-24 LPG. Sand cast. high flow.85-1.62” bolt pattern ∅6. fluorosilicone diaphragm (Waukesha Turbo) Downdraft. (450-540 BTU/ft3). S2-32-1 spring. Refer to your distributor for specific engine application carburetor availability. jet. body. S2-32-2 spring. fluorosilicone diaphragm Sidedraft.05). (λ =. Inc. Refer to the Accessories & Options for information on the Gas Valve Kits. enrichment AFC for catalysts (λ=1.3). (540-640 BTU/ft3).1-1. carburetors must be ordered as sub-assembly modules and assembled by the customer/distributor. Die cast. fluorosilicone diaphragm Updraft. w/J1-25 Digester gas. 5. fluorosilicone diaphragm Sidedraft. w/J1-22 (All gas valve kits except CKV2-69 are designed to operate w/5” H2O column gas inlet pressure. stoichiometric. jet. w/J1-25 (10” H2O column gas pressure) Natural gas. 32 June. In-line. power screw.00”. S2-32-3 spring.6). gaskets & bolts): AB1-31-2: AB1-31-3: J1-32 power jet & V2-60 power valve (natural gas & LPG usage) J1-33 power jet & W1-63 power valve (digester & landfill gas usage) ©2007 IMPCO Technologies. 90o. (450-540 BTU/ft3). w/J1-22 Natural gas. bearings. CKV2-21-3 will be equivalent to the old V2-21 in older 600’s (see Gas Valve Chart on page 31 for gas valve options). B3-43 bushings.69” bore. hose connection (low pressure turbo mount) *= Used to replace 200T w/AT2-9. fly.75” bolt pattern. ©2007 IMPCO Technologies. 4. 3.69” bore.12” bolt pattern. 2007 . B3-43 bushings.50” O. (2) AT2-67 is recommended for turbocharged Waukesha 3521 & 7042 engines because of improved throttle/governor control. lever & gaskets): AT2-17: Throttle body assembly. 4.50” shaft AA3-130: Outlet adapter. ∅3. AT2-17-5 & AT2-67-5 are equipped with turbo seals IMPCO 600 to VARIFUEL 600VF3 Interchange 600VF3 GAS 600VF3 600 MODEL 600VF3 AIR 600VF3 AIR 600VF3 GAS VALVE THROTTLE TO BE HORN VALVE BODY BODY APPLICATION CONVERSION BODY REPLACED MODULE ASSEMBLY ASSEMBLY KIT MODULE 600-1 or 600-1-2 600X-1 or 600X-1-2 DG600X-1-2 AA2-16 600X-3-2 AB1-31-2 600-5 600-9 600-77 & 600-78 600M-2 600XM-2 AB1-30-6 AB1-30-6X CKV2-21-3(1) Updraft Mixer AB1-30-6X CKV2-64 AB1-30-6 CKV2-21-3(1) AT2-17 or AT2-67(2) Waukesha 3521 & 7042 Superior 6G825 AT2-67 Downdraft Mixer (1) Gas valve kit should be selected for the application. 33 June.50” shaft AT2-67: Throttle body assembly.50” shaft AT2-80*: Throttle body assembly. ∅0.19” bore. ∅3. ∅0.Module Group V (Mixture Outlet--body. Inc. shaft. ∅0.12” bolt pattern. B3-43 bushings. ∅3.D. ∅4. Inc.600VF3 Carburetor Assembly (Exploded View) ©2007 IMPCO Technologies. 34 June. 2007 . 2007 . 600 VF3 w/T2-17 Throttle Body (600-960 CFM) & 600 VF3 w/T2-67 Throttle Body (300-650 CFM). 600 VF3-8-2 w/T2-80 (300-650 CFM) ©2007 IMPCO Technologies.600VF3 Carburetor Assembly Dimensions Standard 600VF3 Installation Dimensions. Inc. 35 June. ©2007 IMPCO Technologies. 2007 . Inc. 36 June. Inc.©2007 IMPCO Technologies. 37 June. 2007 . VARIFUEL 600VF3D Duplex Carburetor ©2007 IMPCO Technologies, Inc. 38 June, 2007 Model 600VF3D Specifications Fuel Type(1) ................................................................................... Propane & LPG (50/50 Propane/Butane) Natural Gas (85%+ Methane) Digester Gas (56-72% Methane) Landfill Gas (45-56% Methane) Operating Pressures: Gas Inlet, Normal .......................................................................... 5” H2O over Air Inlet (idle setting) Air Inlet, Maximum .................................................................................................................. 30 PSI Backfire, Peak ......................................................................................................................... 60 PSI Airflow Capacity ...................................................1600 CFM @ 2” HG Depression (T2-18 @ WOT) Horsepower Rating ..........................................................................1000 BHP (Naturally Aspirated) Air/Fuel Ratios ............................................................................ See 600VF3 Gas Valve Chart on page 31 Air/Fuel Adjustments: Low Speed/Load .......................................................... Regulator Pressure (External to Carburetor) High Load.................................................................................................. Power Screw (10+ Turns) Temperature Limits: Max. Operating........................................................................................................................ 250o F Max. Soakback........................................................................................................................ 320o F Materials: Air Valve body (B1-30-6).........................................................................Aluminum (Hard Anodized) Air Valve (V1-17).....................................................................................Aluminum (Hard Anodized) Gas Body (B1-31-2) ................................................................................Aluminum (Hard Anodized) Air Valve Cover (C1-32) ..........................................................................Aluminum (Hard Anodized) Inlet Housing (All)....................................................................................Aluminum (Hard Anodized) Throttle Body (T2-18 or T2-62) ...............................................................Aluminum (Hard Anodized) Diaphragm (D1-20-3) ...................................................................................................Fluorosilicone Guide Bushings.......................................................................... PPS Plastic, Glass and PTFE-filled Gas Valve................................................................................................Aluminum (Hard Anodized) Gas Jet.......................................................... Aluminum (Hard Anodized); Stainless Steel (optional) O-ring Seals ...................................................................................... Buna N; Fluorocarbon optional Fasteners & Power Screw....................................................... Carbon Steel, Zinc plated and baked Springs ............................................................................ High Carbon Steel, Zinc plated and baked Lubrication .............................................................................................................................None Required Safety Certification..................................................................... N/A (Engine User/Producer Responsibility) Emissions Certification .............................................................. N/A (Engine User/Producer Responsibility) (1) Each fuel requires a unique gas valve and jet combination. Refer to 600VF3 section for availabilities. ©2007 IMPCO Technologies, Inc. 39 June, 2007 600VF3D Module ©2007 IMPCO Technologies, Inc. 40 June, 2007 many different gas valves and gas jets are available to address fuel types and BTU/ft3 content. to 2500 BTU/ft3 LPG. ©2007 IMPCO Technologies.2X) Gas Valve/Jet Module Mixture Outlet (Throttle Body) Module (combination Gas Inlet/Mixture Outlet Module) The VARIFUEL 600VF3D is available as a carburetor assembly comprised of all four modules. Please refer to the 600VF3 section for descriptions and part numbers. or available without the Air Inlet Module. it can be mounted in updraft. There are two Throttle Body Modules available for the 600VF3D depending on engine rated BHP. NOTE: Gas valves for specific OEM applications are available. Contact your local IMPCO distributor for more information. Also. Inc. Model 600VF3D: The IMPCO VARIFUEL 600VF3 Duplex carburetor is comprised of two VARIFUEL 600VF3 mixers mounted to a common Throttle/Gas Inlet Body. 2007 . 41 June. They are: • BT2-62-2 for 400 BHP to 799 BHP engines • BT2-18-3 for 800 BHP to 1000 BHP engines The throttle bodies also house the 2” NPT gas inlet. then fine tuning with the spring-loaded power mixture screw (riveted to the Power Valve). Since the VARIFUEL 600VF3D carburetor utilizes two VARIFUEL 600VF3 Mixer Modules.C. downdraft or sidedraft configurations. The 600VF3D carburetor is designed to be a direct replacement for the IMPCO 600D carburetor. High load adjustments are made by first adjusting the fuel pressure and. The VARIFUEL 600VF3D is slightly different from the 400VF3 and 600VF3 in that a carburetor is made up from four modules instead of five. no additional Power Valve/Jet kit is required for different fuel applications. The four modules consist of: 1) 2) 3) 4) Air Inlet Module (Air Horn) Mixer Modules (600VF3. The 600VF3D can accommodate up to 1000 horsepower engines with CFM requirements of up to 1600 CFM and a range of fuels from 400 BTU/ft3 Biogas. Unlike the 400VF3 and the 600VF3. short piston. enrichment AFC for catalysts (λ=1. carburetors must be ordered as sub-assembly modules and assembled by the customer/distributor.4 to 1. w/J1-24 LPG. S2-32-3 spring. w/J1-22 Natural gas. Ingersoll-Rand 8SVG Air Horn. fluorosilicone diaphragm Sidedraft.6).1-1. w/J1-22 (NOTE: All gas valve kits except CKV2-69 are designed to operate w/5” H2O column gas inlet pressure. w/J1-25 (10” H2O column gas pressure) Natural gas. high flow. (λ=. ultralean (λ=1.05). 90O (side) Air Horn. Refer to the Accessories & Options in the 600VF3 section for information on the Gas Valve Kits. jet. (540-640 BTU/ft3). Ingersoll-Rand 8SVG Adapter Assembly. spring. 90O (end) Adapter Assembly. 2007 . stoichiometric. Module Group I (Air Inlet): AA2-17: AA2-18: AA2-23: AA2-62: AA2-38: AA2-44: Air Horn. 12SVG Module Group II (600VF3 Mixer--air valve. fluorosilicone diaphragm (Turbo Draw-through usage) Module Group III (Gas Valve/Jet Kit--gas valve. Inc.3).) ©2007 IMPCO Technologies. Refer to your distributor for specific OEM carburetor availability. w/J1-25 Digester gas. (450-540 BTU/ft3). diaphragm. ultralean (540-640 BTU/ft3). 12SVG Air Horn. Ingersoll-Rand 10SVG. 8” diameter. S2-32-3 spring. w/J1-25 Landfill gas. One module from each of the module groups listed below is needed to make a complete carburetor. S2-123 spring. w/J1-24 Landfill gas.600VF3D Ordering Information 600VF3D Modular Assembly: Except for some specific engine applications. stoichiometric. stoichiometric. Ingersoll-Rand 10SVG. w/J1-23 Digester gas. fluorosilicone diaphragm Sidedraft. cover): AB1-30-6: AB1-30-6H: AB1-30-6X: AB1-30-6S: AB1-30-6SL: Updraft. stoichiometric w/J1-23 (also for Propane w/EB converter) Natural gas. body. screw.85-1. fluorosilicone diaphragm (Waukesha Turbo) Downdraft. throttling AFC for catalysts. fluorosilicone diaphragm Updraft. O-ring & label): CKV2-21-3: CKV2-62: CKV2-63: CKV2-64: CKV2-116: CKV2-65: CKV2-69: CKV2-94: CKV2-96: Natural gas. (450-540 BTU/ft3). S2-32-2 spring. 8” diameter. 42 June. S2-32-1 spring. 13. Inc. ©2007 IMPCO Technologies.75” at bearings) Throttle body assembly.75” shaft (stepped to ∅0. ∅0. 43 June. See chart in 600VF3 Accessories and Options section for gas valve options. power screw/power valve. CKV2-21-3 will be equivalent to the V2-21 in older 600’s.50” at bearings) IMPCO 600D to VARIFUEL 600VF3D Interchange 600D MODEL TO BE REPLACED 600D-1 or 600D-1-2 600DX-1 or 600DX-1-2 600DX-3-2 600DX-2-2 (1) 600D AIR HORN MODULE 600VF3 AIR VALVE BODY ASSEMBLY AB1-30-6 BASE ADAPTER 600VF3 GAS VALVE CONVERSION KIT (2X) CKV221-3(1) 600D THROTTLE BODY MODULE AT2-18-3 APPLICATION Waukesha 3521 Superior 8G-825 Ingersoll-Rand SVG 8 or 10 AA2-18-2 AB1-30-6X AA2-17 AA2-23 AB1-30-6X + P2-59 (2X) AB130-6X AA3-38 AT2-18-573 CKV2-94 AA3-44 (2X) CKV2-94 AT2-62-2 Ingersoll-Rand KVG 10 or 12 Gas valve kit should be selected for the application. lever & gaskets): AT2-18: AT2-62: Throttle body assembly.45 in2 area throttle bore. B3-42 permaglide bearings. ∅0. shaft.75” shaft (stepped to ∅0. fly.Module Group IV (Mixture Outlet--body. bearings. 2007 . B3-42 permaglide bearings. 2070 in2 area throttle bore. 600VF3D Carburetor Assembly Dimensions ©2007 IMPCO Technologies. Inc. 44 June. 2007 . 45 June. 2007 . Inc.©2007 IMPCO Technologies. 46 June.©2007 IMPCO Technologies. 2007 . Inc. ©2007 IMPCO Technologies. 47 June. 2007 . Inc. 48 June. 2007 .Downdraft Updraft 400VF3 Installation Orientations ©2007 IMPCO Technologies. Inc. Starting with the throttle body. the different modules can be installed at 90O increments to one another. Inc. However. Referring to the illustrations on the facing page. it can be rotated in 90O increments to the intake manifold ©2007 IMPCO Technologies. Also. Note the part number for the air valve spring spacer on the updraft and sidedraft illustrations. Additionally.IMPCO VARIFUEL Carburetor Installation A. you can fine tune the air/fuel ratio by adjusting the fuel pressure and power-adjust screw. the 400VF3 (as with all VARIFUEL carburetors) allows you to change its internal gas valves and jets to accommodate different fuel types and air/fuel ratios. This illustration of the 400VF3 shows the fuel inlet on the right side (just below the air horn intake). 49 June. 2007 . If the installation orientation needs to be changed. the updraft installation has the throttle body on top and the downdraft has the throttle body on the bottom. However. updraft or sidedraft configuration. then the proper spacer will have to be installed (or removed). Notice that the fuel inlet on the 400VF3 is in a different position than the 200D. 400VF3 Carburetor Introduction: The VARIFUEL 400VF3 was designed to be a bolt-on replacement for the IMPCO 200D. Figure #1 Mounting Options: Figure #2 The VARIFUEL 400VF3 carburetor can be mounted in a downdraft. The illustration of the sidedraft installation shows the 400VF3 with the optional turbo compressor mounting adaptor (A3-129). The downdraft installation does not require a spacer. Figure #1 is the 200D and figure #2 is the 400VF3. the fuel inlet (part of the Gas Inlet Module) can be rotated to four different positions in relation to the air horn and throttle body. DO NOT use any gasket sealant as some fuels can break down different sealant compounds. It is not necessary to remove the Mixer Module from the Gas Inlet Module. Trial fit the modules in place on the intake manifold. 2007 . 50 June. Inc. the gas inlet can be rotated in 90O increments to the throttle body with a resultant four different positions. Installing the 400VF3 Carburetor: If the carburetor was not assembled by your distributor (or the module orientations need to be changed). or can be replaced with the straight in-line air horn (AA2-69). ©2007 IMPCO Technologies.giving you four different positions in which to line-up the throttle arm to the governor. In this installation. 3) Next. If your installation is going to position the carburetor in an updraft or sidedraft position. reverse the references for the updraft installation. Again. then finish torquing to 1114 ft-lbs in the same cross pattern. the 90O air horn (AA2-70) can be rotated in 90O increments. then finish torquing to 11-14 ftlbs in the same cross pattern. then finish torquing to 11-14 ft-lbs in the same cross pattern. Tighten the bolts evenly in a cross pattern to 10 in-lb. Lightly lubricate the o-ring (S3-138) with clean engine oil. Position the Air Inlet Module (in the correct orientation) and slide it down against the o-ring. then decide how each module will orient themselves to one another. As long as all mounting surfaces are clean and flat. DO NOT use any sealant on the gasket. the throttle body is on the bottom and the air horn is on top. DO NOT use any sealant. G1-27-2 for turbocharged engines) in place on the clean intake manifold. Install the o-ring around the base of the mixer by stretching it slightly. Place a new gasket (G1-25) on top of the Mixture Outlet Module and install the Gas Inlet Module with four 5/16”-18 x 7/8” hex bolts. there should be no problems with gaskets sealing properly. This allows for five different orientations for installation to the intake hose. Also. Mark their orientations to each other with a felt marker across the mating surfaces. it is not advisable to assemble the carburetor on the engine. Place the carburetor over the gasket and install it using four 5/16” bolts. Place a new gasket (G1-27 for naturally aspirated engines. or change to left and right for the sidedraft installation (as warranted). The following installation instructions are tailored to the standard downdraft installation. Tighten the bolts evenly in a cross pattern to 10 in-lb. install the Air Inlet Module. 2) You will now be installing the carburetor (minus Air Inlet Module) onto the intake manifold. Tighten the bolts evenly in a cross pattern to 10 in-lb. install the Gas Inlet Module to the Mixture Outlet Module (throttle body) with the orientation markings lined up. Install the four 5/6”-18 hex bolts. Start by assembling the carburetor in the following sequence: 1) First. Also. Finally. For more information on installing regulators and sub-regulators. refer to Installing Regulators and Sub-Regulators in the Pressure Regulators section. The correct installation requires a regulator and sub-regulator (see figure #3). and the sub-regulator (located within two feet of the carburetor) delivers 5” H2O fuel pressure to the carburetor. Before installing the pipe. if the torque required to tighten the pipe suddenly increases sharply. try another section of pipe or cut 1/8”.Installing the Fuel System: Figure #3 The gas valves in the 400VF3 are designed for a nominal fuel inlet pressure of 5” H2O (measured with engine running at fast idle). In this case. (using a pocket ruler) measure the distance from the outside face of the fuel inlet to the flange face of the power jet (measurement “A” on figure #4). DO NOT over-torque or under-torque the pipe. If it bottoms out without adequate torque to seal the threads. the pipe compresses against the flange on the power jet locking it into the gas inlet (see figure #4).3/16” from the end of the pipe. then remove the pipe and cut a few more threads with the appropriate NPT die. Also. with as few elbows as possible to keep fuel flow restriction at a minimum (45O elbows are preferred over 90O elbows). ©2007 IMPCO Technologies. the end of the pipe has probably seated against the jet boss and should not be tightened any further. 2007 . If you are replacing an IMPCO 200D. then you may need to reroute the fuel pipes and regulator as the 400VF3 has a different fuel inlet location than the 200D. If it will not reach the mark without over torquing. Use a liquid sealant such as LoctiteTM 567 or equivalent. Follow these directions for the fuel system connections: 4) Connect the fuel line to the carburetor. The pipe should be tightened securely. 51 June. Note that the pipe threads into the Gas Inlet Module body and fits around the aluminum power jet in the fuel inlet. For this reason. Inc. the fuel pressure regulator should be located close to the sub-regulator. the main regulator produces around 20” H2O fuel pressure. DO NOT use TeflonTM tape on pipe threads. Use 1 ¼” NPT pipe (refer to your local code for correct type). However. Mark the fuel pipe the same distance from the end with a felt pen. 2007 . and connect the throttle linkage. you can tighten the clamping bolt on the throttle lever to 60 in-lb. ©2007 IMPCO Technologies. This should improve stability. Once you have the carburetor properly adjusted. After the linkage is in place. Once you have aligned the throttle shaft and the governor. This installation will vary depending on the type of throttle control you are using. The throttle shaft can rotate 75O from completely closed to wide open. NOTE: On generator installations.Figure #4 Connecting the Throttle: 5) The throttle lever (L1-12-1) can be installed on either side of the throttle body. This line matches the angle of the throttle fly. Rotate the throttle shaft to the low idle position. 7) Install the throttle lever on the shaft. make sure the throttle shaft is still in the closed position. it is suggested to set the idle stop screw so that the throttle plate is 5O to 10O open to prevent the governor from undershooting when the generator unloads. you can adjust the idle stop screw to fine tune the low idle speed. No matter how you orient the throttle lever to the shaft. For instance. at any angle. 52 June. in figure #5 the throttle is closed. Inc. you can always tell whether the throttle is closed or open by looking at the scribed line on the end of the throttle shaft (see figure #5). Figure #5 6) Set the governor or throttle control for a closed throttle position. and adjust the sub-regulator so the gauge reads 5 inches H2O column. 2007 . ©2007 IMPCO Technologies. This is accomplished by turning the power-adjust screw (engine at full load) in to lean the mixture and out to richen the mixture. refer to VARIFUEL Carburetor Adjusting and Maintenance. unless it is completely closed. Refer to Adjusting Main and Sub-Regulators in the Pressure Regulators section. then there are too many restrictions in the fuel supply line network or the sub-regulator is too small. 8) Locate the power-adjust screw on the carburetor (large. Tighten the screw until the spring is fully compressed. no load). 53 June. best fuel economy. Run the engine at fast idle (rated speed. spring loaded screw directly opposite of the fuel inlet). If it will not. 11) The carburetor can be adjusted for maximum power. NOTE: The power-adjust screw has minimal affect on starting or idling performance. Measure the pressure differential between the outlet side of the sub-regulator and the balance line. then loosen it five (5) full turns.5 inches H2O column. hex head. make sure the main regulator is adjusted correctly. 9) Figure #6 10) Run the engine under full load. refer to VARIFUEL Carburetor Adjusting and Maintenance in this section and verify the engine will achieve maximum power.Adjusting the 400VF3 Carburetor: NOTE: For more information on adjusting VARIFUEL carburetors. Refer to VARIFUEL Carburetor Adjusting and Maintenance for information. This is a good starting point and should only be adjusted further with the engine running under full load. Before performing this step. Make the gauge connections as illustrated in figure #6. or lowest emissions depending on your requirements. If it does. The fuel pressure should not drop below 3. Inc. Inc.Downdraft Updraft 600VF3 Installation Orientations ©2007 IMPCO Technologies. 2007 . 54 June. Figure #7 is the 200T and figure #8 is the 600VF3. However. Also. This illustration of the 600VF3 shows the fuel inlet facing the camera.B. then the proper spring will have to be installed. Finally. Additionally. Also. Notice that the fuel inlet on the 600VF3 is in a different position than the 200T. the updraft installation has the throttle body on top and the downdraft has the throttle body on the bottom. The downdraft spring (S232-2) is yellow. 55 June. the different modules can be installed at 90O increments to one another. 2007 . the 90O air ©2007 IMPCO Technologies. and the sidedraft spring (S2-32-3) is green. Referring to the illustrations on the facing page. and blue (S2-123) (consult your local IMPCO distributor for more information). 90O to the air horn inlet and throttle shaft. 600VF3 Introduction: The VARIFUEL 600VF3 was designed to be a bolt-on replacement for the IMPCO 200T or the IMPCO 600 carburetor. updraft or sidedraft configuration. the 600VF3 (as with all VARIFUEL carburetors) allows you to change its internal gas valves and jets to accommodate different fuel types and air/fuel ratios. it can be rotated in 90O increments to the intake manifold giving you four different positions in which to line-up the throttle arm to the governor (and clockwise or counter-clockwise throttle rotation). Starting with the throttle body. If the installation orientation needs to be changed. The two springs are red (S2-41). you can fine tune the air/fuel ratio by adjusting the fuel pressure and power-adjust screw. However. Inc. the fuel inlet (part of the Gas Inlet Module) can be rotated to four different positions in relation to the air horn and throttle body. Note the part number for the air valve spring on the different illustrations. There are two special springs for updraft installations on turbocharged engines. the gas inlet can be rotated in 90O increments to the throttle body with a resultant four different positions. Figure #7 Figure #8 Mounting Options: The VARIFUEL 600VF3 carburetor can be mounted in a downdraft. the updraft spring (S2-32-1) is silver. DO NOT use any sealant. 2) You will now be installing the carburetor (minus Air Inlet Module) onto the intake manifold. If your installation is going to position the carburetor in an updraft or sidedraft position. Tighten the bolts evenly in a cross pattern to 10 in-lb. Position the Air Inlet Module (in the correct orientation) and slide it down over the Mixer Module. Inc. In this installation. or change to left and right for the sidedraft installation (as warranted). G1-29 for 3 ½” flange) in place on the clean intake manifold. As long as all mounting surfaces are clean and flat. DO NOT use any gasket sealant as some fuels can break down different sealant compounds. Trial fit the modules in place on the intake manifold. The following installation instructions are tailored to the standard downdraft installation. then finish torquing to 29-36 ft-lbs in the same cross pattern. or can be replaced with the straight in-line air horn (AA2-22). DO NOT use any sealant on the gasket. Also. reverse the references for the updraft installation. install the Gas Inlet Module to the Mixture Outlet Module (throttle body) with the orientation markings lined up. 2007 . the throttle body is on the bottom and the air horn is on top. it is not advisable to assemble the carburetor on the engine. 56 June. 3) Next. Mark their orientations to each other with a felt marker across the mating surfaces. Place a new gasket (G1-78) on top of the Mixture Outlet Module and install the Gas Inlet Module with four 3/8”-16 x 1” hex bolts.horn (AA2-16) can be rotated in 90O increments. This allows for five different orientations for installation to the intake hose. then finish torquing to 40 ft-lb in the same cross pattern. Installing the 600VF3 Carburetor: If the carburetor was not assembled by your distributor (or the module orientations need to be changed). DO NOT remove the Mixer Module from the Gas Inlet Module. then decide how each module will orient themselves to one another. Install the four 3/8”-16 x 1” hex bolts. Place a new gasket (G1-38 for 4” flange. Again. Tighten the bolts evenly in a cross pattern to 10 in-lb. Tighten the bolts evenly in a cross pattern to 10 in-lb. there should be no problems with gaskets sealing properly. Place the carburetor over the gasket and install it using four 1/2” bolts. then finish torquing to 29-36 ft-lbs in the same cross pattern. Place a new gasket (G1-76-1) on top of the Gas Inlet Module (around the Mixer Module). Start by assembling the carburetor in the following sequence: 1) First. install the Air Inlet Module. ©2007 IMPCO Technologies. try another section of pipe or cut 1/8”. the fuel pressure regulator should be located close to the sub-regulator. 57 June. Use a liquid sealant such as LoctiteTM 567 or equivalent. Inc.3/16” from the end of the pipe. Follow these directions for the fuel system connections: 4) Connect the fuel line to the carburetor. If it bottoms out without adequate torque to seal the threads. For more information on installing regulators and sub-regulators. (using a pocket ruler) measure the distance from the outside face of the fuel inlet to the flange face of the power jet (measurement “X” on figure #10). if the torque required to tighten the pipe suddenly increases sharply. Note that the pipe threads into the Gas Inlet Module body and fits around the aluminum power jet in the fuel inlet. then remove the pipe and cut a few more threads with the appropriate NPT die. the end of the pipe has probably seated against the jet boss and should not be tightened any further.Installing the Fuel System: Figure #9 The gas valves in the 600VF3 are designed for a constant fuel inlet pressure of 5” H2O (measured with engine running at fast idle). Use 1 1/2” NPT pipe (refer to your local code for correct type). the main regulator produces around 20” H2O fuel pressure. In this case. The pipe should be tightened securely. the pipe compresses against the flange on the power jet locking it into the gas inlet (see figure #10). 2007 . Before installing the pipe. The correct installation requires a regulator and sub-regulator (see figure #9). refer to Installing Regulators and Sub-Regulators in the Pressure Regulators section. DO NOT use TeflonTM tape on pipe threads. with as few elbows as possible to keep fuel flow restriction at a minimum (45O elbows are preferred over 90O elbows). Mark the fuel pipe the same distance from the end with a felt pen. ©2007 IMPCO Technologies. If it will not reach the mark without over-torquing. then you may need to reroute the fuel pipes and regulator as the 600VF3 has a different fuel inlet location than the 200T. and the sub-regulator (located within two feet of the carburetor) delivers 5” H2O fuel pressure to the carburetor. If you are replacing an IMPCO 200T. DO NOT over-torque or under-torque the pipe. Also. However. For this reason. Once you have the carburetor properly adjusted. in figure #11 the throttle is closed. 58 June. Once you have aligned the throttle shaft and the governor. you can adjust the idle stop screw to fine tune the low idle speed. make sure the throttle shaft is still in the closed position. Figure #11 5) Set the governor or throttle control for a closed throttle position. No matter how you orient the throttle lever to the shaft. This line matches the angle of the throttle fly. at any angle.Figure #10 Connecting the Throttle: 4) The throttle lever (L1-12-1) can be installed on either side of the throttle body. This installation will vary depending on the type of throttle control you are using. Inc. 2007 . 6) Install the throttle lever on the shaft. The throttle shaft can rotate 75O from idle to wide open. This should improve stability. ©2007 IMPCO Technologies. Rotate the throttle shaft to the low idle position. For instance. you can always tell whether the throttle is closed or open by looking at the scribed line on the end of the throttle shaft (see figure #11). you can tighten the clamping bolt on the throttle lever to 60 in-lb. and connect the throttle linkage. NOTE: On generator installations. it is suggested to set the idle stop screw so that the throttle plate is 5O to 10O open to prevent the governor from undershooting when the generator unloads. After the linkage is in place. Measure the pressure differential between the outlet side of the sub-regulator and the balance line. then loosen it five (5) full turns. This is a good starting point and should only be adjusted further with the engine running under full load. Figure #12 ©2007 IMPCO Technologies. refer to VARIFUEL Carburetor Adjusting and Maintenance in this section. Refer to Adjusting Main and Sub-Regulators in the Pressure Regulators section. Make the gauge connections as illustrated in figure #12. Run the engine at fast idle (rated speed. 8) Before performing this step. hex head. make sure the main regulator is adjusted correctly. 2007 . spring loaded screw directly opposite of the fuel inlet). Tighten the screw until the spring is fully compressed.Adjusting the 600VF3 Carburetor: NOTE: For more information on adjusting VARIFUEL carburetors. no load). 7) Locate the power-adjust screw on the carburetor (large. Inc. and adjust the sub-regulator so the gauge reads 5 inches H2O column. 59 June. 5 inches H2O column.9) Run the engine under full load. 10) The carburetor can be adjusted for maximum power. refer to VARIFUEL Carburetor Adjusting and Maintenance in this section and verify the engine will achieve maximum power. best fuel economy. This is accomplished by turning the power-adjust screw (engine at full load) in to lean the mixture and out to richen the mixture. The fuel pressure should not drop below 3. Refer to VARIFUEL Carburetor Adjusting and Maintenance for information. If it does. NOTE: The power-adjust screw has no affect on starting or idling performance ©2007 IMPCO Technologies. Inc. then there are too many restrictions in the fuel supply line network or the sub-regulator is too small. 2007 . 60 June. If it will not. or lowest emissions depending on your requirements. ©2007 IMPCO Technologies. 2007 . Inc. 61 June. Inc. 62 June. 2007 .Downdraft Updraft 600VF3D Installation Orientations ©2007 IMPCO Technologies. C. and the sidedraft spring (S2-32-3) is green. the 600VF3D (as with all VARIFUEL carburetors) allows you to change its internal gas valves and jets to accommodate different fuel types and air/fuel ratios. there are 3 different Air Inlet Modules (Air Horn) available. The two springs are red (S2-41). the 90O air horn (side inlet. reverse the references for the updraft installation. In this installation. make sure to orient the adapter correctly and install it with new gaskets. then the proper spring will have to be installed. the updraft installation has the throttle body on top and the downdraft has the throttle body on the bottom. If the installation orientation needs to be changed. or change to left and right for the sidedraft installation (as warranted). updraft or sidedraft configuration. 63 June. ©2007 IMPCO Technologies. The downdraft spring (S232-2) is yellow. the different modules can be installed at 180O increments to one another. If an adapter is being used. Consult your local IMPCO distributor for more information. The 90O air horn (end inlet. Also. If your installation is going to position the carburetor in an updraft or sidedraft position. Note the part number for the air valve spring on the different illustrations. the updraft spring (S2-32-1) is silver. The “D” in the 600VF3D part number designates this as a “Duplex” carburetor. However. Referring to the illustrations on the facing page. the throttle body is on the bottom and the air horn is on top. This allows for five different orientations for installation to the intake hose. There are two special springs for updraft installations on turbocharged engines. it can be rotated in 180O increments to the intake manifold giving you two different positions in which to line-up the throttle arm to the governor (and clockwise or counter-clockwise throttle rotation). The following installation instructions are tailored to the standard downdraft installation. 2007 . 600VF3D Introduction: The VARIFUEL 600VF3D was designed to be a bolt-on replacement for the IMPCO 600D. AA2-18) can be rotated 180O or you can select one of the straight in-line air horns. AA2-62) can be rotated 180O. The instructions are for installing the carburetor without an intake manifold adapter (such as used on Ingersoll-Rand 8. 10 and 12 SVGs). This means there are two VARIFUEL 600VF3 Mixer Modules in the carburetor. and blue (S2-123). Inc. Starting with the throttle body. Mounting Options: The VARIFUEL 600VF3D carburetor can be mounted in a downdraft. Additionally. Place a new gasket (G1-80) on top of the intake manifold and install the Mixture Outlet Module with six 1/2” hex bolts. then decide how each module will orient themselves to one another. Install the carburetor in the following sequence: 1) First. then finish torquing to 40 ft-lb in the same cross pattern. 64 June. Figure #13 2) Start all Air Horn bolts before tightening to 10 in-lbs in the illustrated sequences (see figures 14 & 14A). Mark their orientations to each other with a felt marker across the mating surfaces. Trial fit the modules in place on the intake manifold.Installing the 600VF3D Carburetor: If the carburetor was not assembled by your distributor (or the module orientations need to be changed). Figure #14 Figure #14A ©2007 IMPCO Technologies. 2007 . As long as all mounting surfaces are clean and flat. Tighten the bolts evenly in a cross pattern (see figure #13) to 10 in-lb. Finish tightening them to the following torque values in the same sequences: A. Inc. there should be no problem with gaskets sealing properly. DO NOT use any gasket sealant as some fuels can break down different sealant compounds. DO NOT remove the Mixer Modules from the Mixture Outlet Module. 3/8”-16: 29-36 ft-lbs. 1/4”-20: 90-110 in-lbs. install the Mixture Outlet Module (throttle body/gas inlet) to the intake manifold. B. Use a liquid sealant such as Loctite 567TM or equivalent. and the sub-regulator (located within two feet of the carburetor) delivers 5” H2O fuel pressure to the carburetor. Follow these directions for the fuel system connections 3) Connect the fuel line to the carburetor. 2007 . In this case. with as few elbows as possible to keep fuel flow restriction at a minimum (45O elbows are preferred over 90O elbows).Installing the Fuel System: Figure #15 The gas valves in the 600VF3D are designed for a constant fuel inlet pressure of 5” H2O (measured with engine running at fast idle). the main regulator produces around 20” H2O fuel pressure. Inc. For more information on installing regulators and sub-regulators. ©2007 IMPCO Technologies. For this reason. the fuel pressure regulator should be located close to the sub-regulator. refer to Installing Regulators and Sub-Regulators in the Pressure Regulators section. The correct installation requires a regulator and sub-regulator (see figure #15). Use 2” NPT (refer to your local code for correct type). DO NOT use TeflonTM tape on the pipe threads. 65 June. you will probably want to set the idle stop screw so that the throttle plate is 5O to 10O open. NOTE: On generator installations. you can always tell whether the throttle is closed or open by looking at the scribed line on the end of the throttle shaft (see figure #16). Adjusting the 600VF3D Carburetor: NOTE: For more information on adjusting VARIFUEL carburetors. Tighten the screw until the spring is fully compressed. Figure #16 5) Set the governor or throttle control for a closed throttle position. This line matches the angle of the throttle fly. Once you have aligned the throttle shaft and the governor. 2007 . Rotate the throttle shaft to the low idle position. refer to VARIFUEL Carburetor Adjusting and Maintenance in this section 7) Locate the power-adjust screw on the carburetor (large. 6) Install the throttle lever on the shaft. The throttle shaft can rotate 75O from idle to wide open. at any angle. Inc. This should improve stability. After the linkage is in place. you can adjust the idle stop screw to fine tune the low idle speed. This is a good starting point and should only be adjusted further with the engine running under full load. make sure the throttle shaft is still in the closed position. This will prevent the governor from undershooting when the generator unloads. ©2007 IMPCO Technologies. 66 June. in figure #16 the throttle is closed. This installation will vary depending on the type of throttle control you are using. spring loaded screw directly opposite of the fuel inlet). hex head. Once you have the carburetor properly adjusted. For instance.4) The throttle lever (L1-12-1) can be installed on either side of the throttle body. you can tighten the clamping bolt on the throttle lever to 60 in-lb. then loosen it five (5) full turns (never loosen the screw by more than 10 turns from fully seated). No matter how you orient the throttle lever to the shaft. and connect the throttle linkage. make sure the main regulator is adjusted correctly. 2007 . 10) The carburetor can be adjusted for maximum power. then there are too many restrictions in the fuel supply line network or the sub-regulator is too small. or lowest emissions depending on your requirements. 67 June. NOTE: The power-adjust screw has no affect on starting or idling performance. This is accomplished by turning the power-adjust screw (engine at full load) in to lean the mixture and out to richen the mixture. ©2007 IMPCO Technologies. Run the engine at fast idle (rated speed. The fuel pressure should not drop below 3.8) Before performing this step. If it does. refer to VARIFUEL Carburetor Adjusting and Maintenance in this section and verify the engine will achieve maximum power. no load). Measure the pressure differential between the outlet side of the sub-regulator and the balance line. Inc.5 inches H2O column. best fuel economy. and adjust the sub-regulator so the gauge reads 5 inches H2O column. If it will not. Refer to VARIFUEL Carburetor Adjusting and Maintenance for information. Figure #17 9) Run the engine under full load. Refer to Adjusting Main and Sub-Regulators in the Pressure Regulators section. Make the gauge connections as illustrated in figure #17. Figure #18 VARIFUEL 600VF3 Illustrated ©2007 IMPCO Technologies. 2007 . 68 June. Inc. NOTE: A leaner air/fuel ratio will usually reduce the engine’s power output. For some engines (in some situations).VARIFUEL Carburetor Adjusting and Maintenance Adjusting the VARIFUEL Carburetor The power adjust screw on the VARIFUEL carburetor sets the air/fuel mixture for the engine under medium and heavy loads. To Adjust for Maximum Power: Connect a manifold vacuum gauge to the intake manifold on the engine. First. Run the engine under full load. under load.5%. You should adjust this screw while the engine is running at full power. turn the power adjust screw IN until the vacuum gauge drops by 1” to 1. ©2007 IMPCO Technologies. especially on naturally aspirated (non-turbocharged) engines. some engines may not run well at such a lean setting. The engine is now set for best fuel economy. and turn the power adjust screw in (clockwise) until the exhaust gas contains approximately 5 to 7% oxygen. 2007 . 69 June. opposite of the fuel inlet (see figure #18). However. Optional: Tighten the power adjust screw even further. and the carburetor adjusted for maximum power. turn the power adjust screw for the highest vacuum reading. Inc. until the exhaust gas oxygen content reaches 8. However. It is the hex-head screw (with a spring on it) located on the lower half of the carburetor. Keep the engine running under full load. All vacuum readings are based on sea level readings. Make adjustments to readings as necessary to compensate for altitude. at maximum rated rpm.5” Hg. To Adjust for Best Emissions: You will need to install an exhaust gas analyzer (such as the Infrared Industries FGA-5000). the position of the power adjust screw will not affect starting or idling performance. adjust the carburetor for maximum power. While monitoring the manifold vacuum. To Adjust for Best Fuel Economy: With the engine running at full load and rated rpm. meeting emission standards can reduce the engine’s power by up to one third. 00 = The Stoichiometric A/F Ratio Controlling the Air/Fuel Ratio (Fuel Pressure and Power Valve Position): When the engine is starting and idling. These high velocities create a vacuum. and LEAN the air/fuel mixture. there is very little air flowing through the carburetor. but they have only a small effect on the full-load air/fuel ratio. When the engine is running at full load. turning the power adjust screw IN (clockwise) will decrease the fuel inlet area. On IMPCO VARIFUEL stationary-engine carburetors. adjusting the fuel pressure is counterproductive. 70 June.4 and λ= 1.Lean Burn Operation Introduction: Lean burn operation allows an engine to meet exhaust emission limits without an expensive catalytic converter. Not only will such changes disrupt the starting and idling response. Figure #19 λ 1. the air/fuel ratio is determined mainly by the fuel pressure coming from the regulator (or sub-regulator where installed). This vacuum effect (called the Bernoulli Effect) is five to eight times stronger than the fuel pressure setting of the regulator. which reduces the peak combustion temperature. We recommend that you turn the power adjust screw in increments of one-half turn or less. When the engine is running at full load. therefore producing less NOX. Inc. less CO is produced. higher-flow conditions. there is excess air in the combustion mixture. the air velocities through the carburetor are much higher than they are at idle. ©2007 IMPCO Technologies. you control the air/fuel ratio mainly by adjusting the power valve. In addition. You may need to vary this pressure by ±1. By keeping the air/fuel ration between λ= 1. which draws fuel into the carburetor. Under these higher-vacuum. Lean burn gas valves for IMPCO carburetors are nominally designed for 5 inches H2O fuel inlet pressure. In this case. 2007 .7 (see figure #19).5 inches H2O to accommodate different engines and fuel characteristics. the engine could cross that limit. Setting the Carburetor Power Adjust Screw: In order to set the carburetor for lean burn operation. For this reason.0. a leaner air/fuel ratio reduces the engine’s peak power output. you can thermostatically control the temperature of the air leaving the aftercooler. and turn the power adjust screw IN (clockwise) until the exhaust gas contains approximately five to seven percent (5-7%) oxygen.clockwise). some engines may not run well at such a lean setting. This calls for an adjustment strategy that is opposite from most operators’ previous experience. until the exhaust gas oxygen reaches 8. For some engines (in some situations). Optional: You can tighten the power adjust screw even farther. because when the temperature changes. If detonation occurs. you should avoid the engine’s detonation limit (as discussed later). propane. Oil contamination is highly likely in this range and can lead to severe bearing. you will need to install an exhaust gas analyzer (such as the Infrared Industries FGA-5000). The best way to keep control of the air/fuel ratio is to regulate the temperature of the air going into the carburetor.) and ignition timing. the temperature of the air as it is going toward the carburetor. Beware of Detonation: With higher turbocharger boost levels.5%. However. On turbocharged engines. The carburetor alone cannot compensate for different air temperatures. the risk of detonation increases. the detonation risk decreases. Richening the mixture will increase detonation. On turbocharged engines. 71 June. and is highly dependent on fuel constituents (ethane. lean the mixture (turn the power adjust screw IN. you may need a custom gas valve. valve. CAUTION: Avoid operation in the lean range between 2. We recommend that you set the power adjust screw at least one half turn away from the lean misfire limit and the detonation limit. In general. 2007 . ring and liner damage.5% and 4. This risk is greatest as the engine operates closer to λ = 1. meeting emission standards can reduce the engine’s power by up to one third. etc. which can crack pistons and valves. Run the engine under normal load.5% O2. DO NOT richen the air/fuel ratio. The cooling system should be controlled by the aftercooler’s outlet temperature.Effects of Temperature: The air/fuel ratio varies with the temperature of the incoming air. and could even break the crankshaft. Likewise. that is. As the mixtures become leaner. ©2007 IMPCO Technologies. piston. If these two limits are less than one turn apart. especially on naturally aspirated (non-turbocharged) engines. The exact detonation limit varies from engine-toengine. you may need up to twice as much boost to compensate for this loss of power. Inc. you should avoid pushing the lean misfire limit. because the combustion process is diluted and slowed with excess air. remove the Gas Jet from the Air Valve body (you may have to use a pair of pliers). Figure #21 ©2007 IMPCO Technologies. 3) On the underside of the Mixer Module (Air Valve body) you will find two jet cover screws (S1-3 in figure #20). 2) Remove the 6 screws holding the Mixer Module to the Gas Inlet Module and remove the mixer. Figure #20 4) Now. 2007 . Loosen both of them a few turns. 72 June. Inc.Changing the Gas Valve Jet Kit 400VF3: Disassembly: 1) Remove the Air Inlet Module (Air Horn) from the carburetor. If this happens. In rare cases. Turn the mixer over and remove the spacer (note the step in the spacer for the spring. Figure #23 ©2007 IMPCO Technologies. there will be a spacer under the spring. 73 June. Remove the four screws securing the Air Valve cover. Use a 7/16” socket and extension to keep the stub shaft from turning while you tighten the Gas Valve retaining screw to 13-17 in-lbs (see figure #23). the stub shaft may slip and rotate as you turn the screw. If the carburetor was installed in an updraft or sidedraft configuration. Put the new V2 Gas Valve (Gas Valve part #s are marked on the flat side of the valve) on the stub shaft (S5-31).5) Hold the Air Valve from twisting (within the Air Valve body) while you remove the Gas Valve screw (see figure #22). Figure #22 6) Remove the Gas Valve and inspect the piston o-ring (S3-132) for wear or damage. you will need to stop it from turning as follows: A.this faces UP towards the cover when re-installed). B. Remove the Air Valve cover and the spring beneath it. Reassembly: 1. Inc. Replace the o-ring where necessary. Keep the Air Valve from twisting (as in disassembly step #5) as you install and tighten the screw (S1-66) to 13-17 in-lbs. 2. 2007 . Figure #25 5. 2007 . Reinstall the spring and spacer (where applicable.make sure the spacer is installed as in figure #24). ©2007 IMPCO Technologies. Tighten the two jet holder screws (S1-3) evenly to 16-20 in-lbs (see figure #20). Insert the new Gas Jet into the Air Valve body (shoulder facing up). The jet should fit with the flange shoulder flush with the Air Valve body surface. Inc. Be sure to align the vacuum port holes in all three pieces (see figure #25) and tighten the four screws evenly to 16-20 in-lbs. 74 June.3. Reinstall the Air Valve cover. Figure #24 4. 2. Lubricate the new Gas Jet o-ring with clean engine oil and slide it onto the new Gas Jet (see figure #26). NOTE: The o-ring supplied with the new Gas Valve kit should be the correct one for your fuel type. Do not confuse the old and new o-rings. Natural gas applications use the Nitrile o-ring (S3-133) and landfill or digester gas applications use the Viton o-ring (S3-133-2). Figure #26 3. Carefully position the Mixer Module on the Gas Inlet Module. Start all six screws before tightening them evenly and in a diagonal sequence to 16-20 in-lbs (see figures #27 & 27A). Figure #27 Figure #27A ©2007 IMPCO Technologies, Inc. 75 June, 2007 4. Lightly lubricate (with clean engine oil) and install a new o-ring (S3-138) around the base of the Mixer Module (see figure #28). Figure #28 5. Orient the Air Inlet Module (if 90O Air Horn is being used) as necessary and carefully slide it over the Mixer Module (being careful not to disturb the o-ring). Start all four 5/16” x 7/8” bolts into the Air Horn and tighten them evenly to 90-110 in-lbs. ©2007 IMPCO Technologies, Inc. 76 June, 2007 600VF3 and 600VF3D: NOTE: The 600VF3D uses two 600VF3 Mixer Modules. The disassembly and reassembly steps between the 600VF3 and 600VF3D carburetors are similar. The instructions are tailored to the 600VF3 carburetor. Any noteworthy difference with the 600VF3D will be called out in the instructions. Disassembly: 1) Remove the Air Inlet Module (Air Horn) from the carburetor. 2) Remove the six screws holding the Mixer Module to the Gas Inlet Module (600VF3DMixture Outlet Module) (Throttle Body) and remove the mixer. 3) Remove the J1 Gas Jet and o-ring (S3-78) from the Mixture Outlet Module (see figure #29). Figure #29 (600VF3 Illustrated) 4) Hold the Air Valve from twisting (within the Air Valve body) while you remove the Gas Valve screw (see figure #30). Figure #30 ©2007 IMPCO Technologies, Inc. 77 June, 2007 5) Remove the Gas Valve and inspect the piston o-ring (S3-76) for wear or damage. Replace the o-ring where necessary (see figure #31). Figure #31 Reassembly 1) Install the new V2 Gas Valve onto the stub shaft (S5-29). Keep the Air Valve from twisting (as in disassembly step #4) while tightening the screw (S1-3) to 27-33 in-lbs. NOTE: Gas Valve part numbers are marked on the flat side of most valves (see figure #32). Figure #32 2) Lightly lubricate the Gas Jet o-ring (S3-78) and install on the J1 Gas Jet. 3) Install the Gas Jet/o-ring into the Gas Inlet Module (600VF3D–Mixture Outlet Module). ©2007 IMPCO Technologies, Inc. 78 June, 2007 4) 5) Orient the Mixer Module correctly and set it in place on the Gas Inlet Module (600VF3D–Mixture Outlet Module). Make sure the Mixer Module is sitting squarely and flat against the Gas Inlet Module (600VF3D–Mixture Outlet Module). Start all six screws before tightening them to 27-33 in-lbs in a diagonal sequence (see figures #33 & 33A). Figure #33 (600VF3 Illustrated) 6) Figure #33A Set a new Air Horn gasket (part number dependent on model) in place around the Mixer Module(s). Orient the Air Horn correctly for your installation and carefully set it in place over the Mixer Module(s). Start all Air Horn bolts before tightening to 10 in-lbs in the illustrated sequences. Finish tightening them to the following torque values in the same sequences: A. B. 1/4”-20: 90-110 in-lbs. 3/8”-16: 29-36 ft-lbs. 7) ©2007 IMPCO Technologies, Inc. 79 June, 2007 Back the set screw off 2 to 3 turns with a 3/32” Allen wrench. 2007 . Disassembly: 1) Close the fuel shut-off valve and bleed all fuel from the fuel line. 4) Using an open-end or box-end wrench (9/16” for 400VF3. keep the Power Adjust Screw from turning while removing the Power Valve with a 7/16” socket (see figures 34 through 34B). You will need to access the port where the fuel line enters the carburetor (in the Gas Inlet Module). 80 June. In this case. 2) Remove the fuel line. You may need to change the Power Valve and Power Jet to accommodate different types of fuel. If necessary. Figure 34 (400VF3 Gas Inlet Module) Figure 34A (600VF3 Gas Inlet Module–Digester Gas or Landfill Gas) ©2007 IMPCO Technologies. 3) If equipped. remove the Gas Inlet Module and Mixer Module from the Mixture Outlet Module (Throttle Body). NOTE: If you are using propane or lean-burn NG at low rpm. loosen the Power Jet set screw jam nut with a 3/8” wrench. The Power Valve and Power Jet control the volume of fuel entering the carburetor when the engine is under load. fixed-plate Power Valve and no Power Jet. you may wish to use a 400VF3 Mixer Module on a 600VF3 Gas Inlet Module and Mixture Outlet Module (Throttle Body).Changing the Power Valve and Power Jet 400VF3 and 600VF3: NOTE: The 600VF3D carburetor has a riveted in. Inc. 3/4” for 600VF3). Remove the Power Jet from the Gas Inlet Module. you will need to use an A3-128 adapter plate. The pipe should be tightened securely. Use a liquid sealant such as LoctiteTM 567 or equivalent. if the torque required to tighten the pipe suddenly increases sharply. reinstall them now with a new gasket.Figure 34B (600VF3 Gas Inlet Module. Mark the fuel pipe the same distance from the end with a felt pen. 3) Referring to figures 34 through 34B. 2) Install a new Nylock nut (N1-22) onto the Power Adjust Screw and tighten it to 38-42 inlbs. DO NOT over-torque or under-torque the pipe. the end of the pipe has probably seated against the jet boss and should not be tightened any further. 2007 .NG or Propane) Reassembly: 1) Install the new Power Valve onto the Power Adjust Screw. LFG applications) are installed with the concave side towards the screw (see figures 34 and 34A). Inc. However. orient the Power Jet correctly and install it into the Gas Inlet Valve (seat it firmly and squarely in place by hand). 4) If you had to remove the Gas Inlet and Mixer Modules from the Throttle Body. (using a pocket ruler) measure the distance from the outside face of the fuel inlet to the flange face of the power jet (measurement “A” on figure #35). If it bottoms out without adequate torque to seal the threads.3/16” from the end of the pipe. 81 June. 5) Before reconnecting the fuel inlet pipe. try another section of pipe or cut 1/8”. DO NOT use TeflonTM tape on pipe threads. The Belleville washer used on the 400VF3 and the 600VF3 (DG. If it will not reach the mark without over-torquing. then remove the pipe and cut a few more threads with the appropriate NPT die. Figure #35 (600VF3 Illustrated) ©2007 IMPCO Technologies. NOTE: You will have to set the power adjust screw according to whatever emissions. Always set the power adjust screw while the engine is running under load. 2007 . and fuel economy needs you have.6) Tighten the Power Jet set screw and jam nut. power. 82 June. 7) After reconnecting the fuel line. ©2007 IMPCO Technologies. Refer to Adjusting the VARIFUEL Carburetor. check for leaks before opening the fuel shut-off valve. Inc. 400VF3: Hard Parts: Quantity (per Carb) 1 1 1 1 1 1 IMPCO Part Number D1-25 P2-62-2 B3-57 B3-58 V1-16 S1-12 Description Diaphragm. and they are also the most likely to be damaged if an engine backfires. These are the parts which wear during normal operation of the carburetors. #8-32 x 5/16” pan head SEMS Gaskets: Quantity (per Carb) 1 1 1 1 Gasket Part Number S3-138 (O-ring) G1-25-2 (Turbo) G1-25 G1-27-2 (Turbo) Usage Description Air Inlet Module Gas Inlet Module Mixture Outlet Module To To To Gas Inlet Module Mixture Outlet Module Intake Manifold 1 G1-27 ©2007 IMPCO Technologies. Inc. 83 June.Recommended Service Parts Following is a list of service parts for the IMPCO VARIFUEL carburetors. IMPCO recommends that you keep these parts in your inventory. silicone (yellow) Plate for diaphragm Upper guide bushing (brown) Lower guide bushing Air valve (anodized aluminum) Screws for diaphragm cover. 2007 . T2-17 Mixture Outlet Modules T2-9 Mixture Outlet Module T2-80 Mixture Outlet Module To To To Air Inlet Pipe Gas Inlet Module Mixture Outlet Module G1-29 S3-138 To Intake Manifold ©2007 IMPCO Technologies. 2007 .600VF3: Hard Parts: Quantity (per Carb) 1 1 1 1 IMPCO Part Number RK-D1-20-3 B3-60 V1-17 C1-32 Description Repair Kit. 84 June. Includes plate. fluorosilicone diaphragm (blue). Lower guide bushing (brown) Air valve (anodized aluminum) Cover. screws & upper anti-wear bushing. Inc. diaphragm Gaskets: Quantity (per Carb) 1 1 1 Gasket Part Number G1-77 G1-76-1 G1-78-1 G1-38 1 Usage Description Air Inlet Module Air Inlet Module Gas Inlet Module T2-67. Inc. screws & upper anti-wear bushing. fluorosilicone diaphragm (blue). Includes plate.600VF3D: Hard parts: Quantity (per Carb) 2 2 2 2 IMPCO Part Number RK-D1-20-3 B3-60 V1-17 C1-32 Description Repair Kit. Lower guide bushing (brown) Air valve (anodized aluminum) Cover. 2007 . diaphragm Gaskets: Quantity (per Carb) 1 Gasket Part Number G1-79 G1-82 G1-86 G1-151 (Turbo) 1 G1-81-1 Usage A2-17 A2-18-2 A2-62 A2-23 A2-17 A2-18-2 A2-23 A2-62 A2-17 A2-18-2 A2-23 A2-62 T2-18 T2-18-3 T2-62-2 A3-38 Air Inlet Module Description To Air Inlet Pipe AT2-18-3 AT2-62-2 Air Inlet Module To AT2-18-1 Mixture Outlet Module Adapter Plate Mixture Outlet Module 1 Optional G1-80 G1-79 To To Intake Manifold or Adapter Plate Intake Manifold G1-86 A3-44 ©2007 IMPCO Technologies. 85 June. Inc. 2007 . 86 June.Figure #36 ©2007 IMPCO Technologies. But their output is non-linear because their spring loading system causes much of the droop(1) found in regulator operation. Instrument air or gas supply. Water pressure control. requiring no external power sources. Direct-Operated Regulators (Single-Stage Regulators) Figure #36: These types of regulators can handle applications in which an outlet pressure change of 10% to 20% of setpoint is acceptable. 2007 . they are more compact and lighter than other control systems. In most pressure reducing regulators. Therefore. 87 June. increasing force of downstream pressure closes the regulator main valve. construction and operation. Fuel gas to burners. ©2007 IMPCO Technologies. It is normally expressed as a percent and is often referred to as proportional band. Typical applications include: • • • • • • Industrial. commercial. to attain high flow rates without excessive droop. The value at which the reduced pressure is maintained is the outlet pressure setting of the regulator. Inc. Tank blanketing.Pressure Regulators Introduction: A pressure regulator maintains a desired. the simplicity of regulators makes them a standard of the industry. Pressure regulators are simple control devices in which all of the energy needed for operation is derived from the controlled system. Pressure regulators typically cost less to buy. the better it is (as long as it does the job). and gas service. The biggest advantages of direct-operated regulators include simplicity of design. Based on the axiom that the simpler a control system is. Also. (1) Droop is defined as the decrease in controlled pressure that occurs when moving from a low-load to full-load flow condition. install and maintain. another form of loading must be used. Two Main Types of Regulators: All regulators for pressure control are either direct-operated or pilot-operated. reduced outlet pressure while providing the required fluid or gaseous flow to satisfy a variable downstream demand. Steam service. amplifier or multiplier) multiplies a small change in downstream pressure into a large change in the loading pressure applied to the regulator. Applications are similar for those with direct-operated regulators. Inc. 88 June. but where greater accuracy and/or higher flow is required. These provide versatility in controlling pressure at a given location in the downstream system. instead of relying upon spring force to open the main valve. It is this multiplying effect that enables pilot-operated regulators to control pressure with greater accuracy. ©2007 IMPCO Technologies. Almost all pilot-operated regulators have downstream control lines. However. This type of regulator does the same job as one that is direct-operated. 2007 . The pilot (also called a relay.Pilot-Operated Regulators (Two-Stage Regulators) Figure #37: Figure #37 These types of regulators are a better choice when the allowable change in outlet pressure must be less than 10% of the outlet pressure setpoint. an auxiliary device called the pilot supplies loading pressure against the regulator diaphragm to open the valve. Inc. orifice size and spring selection. inlet pressure and droop. The regulator body size will not necessarily be the same size as the pipeline and should never be larger. if more than one orifice can handle the flow. In general. Acceptable accuracy or droop. the regulator body is one size smaller than the pipe size. To correctly size a regulator. The minimum inlet pressure and maximum flow are very critical in regulator sizing.Regulator Factors to Consider: Regulator capacity information is based on very specific flow conditions. The regulator has to be large enough to pass the maximum flow required even with a low inlet pressure or a starved condition at the inlet. Maximum expected flow rate. 89 June. which means a flow rate typically is given for a specific setpoint. use the spring with the lower range to gain better accuracy. Every regulator represents a blend of such factors as: • • • • • Price Capacity Accuracy Stability Simplicity • Speed of response Comparison of Regulator Types: Type Direct-Operated Pilot-Operated = Better Accuracy Capacity Speed of Response Cost ©2007 IMPCO Technologies. This improves performance and minimizes shut-off problems. 2007 . Most soft seated regulators maintain the pressure within reasonable limits down to zero flow. Flowing medium. choose the smallest diameter orifice. The flow rate will vary depending on regulator body size. you need to consider: • • • • • Maximum and minimum inlet pressure. Best performance is obtained with the smallest body and orifice selection that will handle the flow. Temperature. Often. If two or more springs have published pressure ranges that cover the desired pressure setting. IMPCO IMP Regulator ©2007 IMPCO Technologies. 2007 . 90 June. Inc. IMPCO IMP Regulators Fuel Pressure Regulators for VARIFUEL Carburetors Specifications: Dimensions (Standard Pressure Reduction Valves): Standard A B C D E F G H Application Pressure Overall Overall Overall Bottom to Centerline Center of Inlet & Vent Boss Reduction Length Width Height Center of to Center Vapor Outlet Diameter Valve Vapor of Vent Fluid NPT Fuel Boss Outlet to Outlet Top of Vent Boss CA55/100 IMP52 3 3/16” 3 ¼” 5 1/16” 1 ½” 1 3/32” 2” ¾” 1/8” Series 200 IMP53 3 5/8” 3 7/8” 5 9/16” 1 11/32” 1 15/32” 2 11/32” 1” 1/8” Series 400VF3 IMP60 4 3/8” 5 7/16” 6 7/16” 1 21/32” 1 27/32” 2 7/8” 1 ¼” 1/8” Series 600VF3 IMP81 6” 7” 8 3/8” 2 1/32” 2 3/8” 3 1/16” 1 ½” 1/8” Series 600VF3 & IMP91 7 1/8” 9 1/8” 10 ½” 2 7/16” 3 ¼” 4 3/16” 2” 1/8” 600VF3D Series ©2007 IMPCO Technologies. 91 June. Inc. 2007 . 92 June. For more information. custom-built gas valves and jets are available for special applications. ©2007 IMPCO Technologies. Inc. It can be adjusted for best power. 2007 . contact your nearest IMPCO distributor. the fuel pressure will have little effect on the air/fuel ratio. Power Adjust Screw: The power adjust screw on the carburetor determines the air/fuel mixture when the engine is at full power (rated speed under full load). the power adjust screw is set too far in.General Information: There are three main factors which affect the air/fuel ratio. The power adjust screw will have little effect when the engine is starting or idling. • Power adjust screw on the carburetor. Gas Valve and Jet: The IMPCO VARIFUEL series carburetors are designed to accept various sizes and shapes of gas valves and jets to accommodate different fuel types and various engine performance curves. They are: • Size and shape of the gas valve. • Fuel pressure entering the carburetor. Fuel Pressure: The pressure of the fuel entering the carburetor will have a significant effect on the air/fuel ratio when the engine is starting. If it does. or running under light loads. Under heavy loads. In addition. and the engine will not be able to develop full power. idling. or best emissions. best fuel economy. For this reason. and a sub-regulator (located within two feet of the carburetor) produces 5” H2O column of fuel pressure to the carburetor (see figure #38). then there are too many restrictions in the fuel supply line network or the sub-regulator is too small. If it will not. In this case. If it does. 93 June. Inc. In addition. the fuel pressure sub-regulator should be located close to the carburetor. 600VF3 and 600VF3D carburetors are designed for a constant fuel inlet pressure of 5 inches water column (5” H2O column.Standard IMPCO VARIFUEL Carburetor Fuel Inlet Pressure: The IMPCO VARIFUEL 400VF3. with no elbows to restrict the flow. NOTE: The input pressure to the sub-regulator (IMP) must not exceed 1 PSI (27” H2O column) of fuel pressure. 2007 . the fuel inlet pressure should not drop by more than 1. Figure #38 ©2007 IMPCO Technologies. The best approach is to use a main regulator and a subregulator in series. refer to VARIFUEL Carburetor Adjusting and Maintenance on page 69 and verify the engine will achieve maximum power. measured with the engine at fast idle).5” H2O column as the engine approaches full power (rated speed under full load). the main regulator produces around 20” H2O column of fuel pressure. 12 53 1" 60 1 1/4" 81 1 1/2" 91 2" ©2007 IMPCO Technologies.64 0.000 6.45 1.500 9.37 0.500 3.16 5.22 0.35 2.95 3.78 0.000 9.80 4.71 1.27 0.27 3.16 1.24 0. Differential pressure (inlet pressure minus outlet pressure) must be at least twice the pressure drop value for practical use.200 1.15 0.71 0.90 2.18 0.10 0.86 3.90 5.09 0.93 0.14 0.09 0.13 7.000 900 800 700 600 500 400 300 200 100 IMP Model Pipe Size Pressure Drop (Inches Water Column) 5.500 5.55 2.12 2.16 0.800 1.79 1.31 2.54 0.900 1.65 1. Inc.80 4.33 2. Maximum recommended capacity limit is at a flow equivalent to 4.46 2. Rate of Flow (CFH/0.56 0.48 1.0 inches H2O pressure drop.500 7.000 7.87 1.78 3.90 4.400 1.39 3.500 8.000 4.41 0.63 0.39 1.13 1.37 3.600 1.500 4. 2007 .95 0.38 1.90 2.73 0.58 2.85 3.700 1.64 Specific Gravity of Gas) 10.09 1.Flow Capacities: The following chart illustrates pressure drop values for each model IMP regulator in the full open position.28 0.22 0.70 0. 94 June.500 6.33 0.76 1.23 0.000 2.62 0.03 2.07 1.82 2.30 4.44 0.26 1.78 0.000 5.32 0.52 0.38 0.000 1.20 0.58 1.18 52 3/4" 4.43 0.20 0.95 4.500 2.13 4.52 2.24 0.25 0.500 1.100 1.84 0.300 1.50 0.000 3.39 0.000 8.20 0. Also. DO NOT connect the regulators backwards. Even when the primary regulator is close to the carburetor. you should install a balance line between the primary regulator. This is especially important on turbocharged engines. The use of copper tubing is not recommend. Figure #39 The IMP sub-regulator must be mounted upright (as in figure #39). and install a 1” NPT reducer in its place. If the primary regulator will be more than twelve feet away from the carburetor. the primary regulator can be any distance from the carburetor. In this configuration. the IMP sub-regulator is recommended for more precise control of the fuel pressure.Regulator Installation Primary Regulator & Sub-Regulator: The regulator should be located in the fuel line (as close to the carburetor as possible) to reduce restrictions and prevent surging in the fuel system. Inc. downstream from the primary regulator (see figure #39). Balance Lines: In all configurations. 2007 . subregulator (if used) and the carburetor inlet (see figure #39). On some primary regulators. a turbocharged engine will be starved for fuel under any significant load. the arrow on the IMP sub-regulator represents the direction of fuel flow. Never apply more than 1 PSI (27” H2O) to the IMP sub-regulator. Use 5/16” or (preferably) 3/8” pipe or steel tubing for the 400VF3 and 600VF3 carburetors and 3/8” or (preferably) ½” ID pipe or steel tubing for the 600VF3D duplex carburetor. an IMP sub-regulator is required. you will need to remove the vent screen. ©2007 IMPCO Technologies. Without the balance line. but the IMP sub-regulator should be within two feet of the carburetor. which allows better control of the exhaust emissions and fuel economy. 95 June. use local code approved pipe. Use a liquid thread sealant (such as Loctite 567 or equivalent) on all pipe threads. 96 June. Inc. because it can foul the carburetor. 2007 . DO NOT use Teflon tape. ©2007 IMPCO Technologies. install it between the sub-regulator and the carburetor (see figure #40).Air/Fuel Ratio Controller: If you use a separate air/fuel ratio controller. Figure #40 Fuel Lines: For fuel line connections. no load). 97 June. This should prevent misfire and detonation while you are setting the fuel pressure. A good starting point for this screw is four turns out from base (screw spring fully compressed) for the 400VF3 and 600VF3 carburetors and three turns from base for the 600VF3D duplex carburetor. lean the mixture (tighten the power adjust screw) slightly before you proceed. you will need a custom gas valve. Primary Regulator Only: If you will be using a primary regulator without a sub-regulator.include in ITK-1 tool kit) to the fuel line 4-18” from the carburetor. Connect the low pressure side of the meter/gauge to the balance line (see figure #41). Following the manufacturer’s instructions. The power adjust screw (see figure #39) determines the air/fuel ratio while the engine is under load. Figure #41 2) 3) Turn on the fuel supply. 2007 .Adjusting Primary and Sub-Regulators Before you can start the engine. NOTE: If detonation occurs. adjust the regulator until the meter/gauge reads 5” H2O column. Start the engine. ©2007 IMPCO Technologies. Adjusting the Primary Regulator: 1) Connect the high pressure side of a manometer or sensitive pressure gauge (such as the IMPCO TG-010. you will need to preset the power adjust screw. If you cannot take the engine from idle to full load without detonation. and run it at fast idle (rated speed. Inc. you will need to install the manufacturer’s recommended spring to maintain 5” H2O outlet pressure. Inc. Adjusting the Primary Regulator: 1) Connect the high pressure side of a manometer or sensitive pressure gauge (such as the Dwyer Magnehelic™ number 2-5040) to the IMP sub-regulator input pressure port. 2007 . adjust the primary regulator first. ©2007 IMPCO Technologies. 98 June. You will need to install the primary regulator manufacturer’s recommended spring to maintain 20” H2O outlet pressure. Connect the low pressure side of the meter/gauge to the balance line (see figure #42). Connect the low pressure side of the meter/gauge to the balance line (see figure #42). 2) Figure #42 3) Unscrew the dust cap on the primary regulator and turn on the fuel supply.Primary Regulator with IMP Sub-Regulator: If you are using both a primary regulator and an IMP sub-regulator. Connect the high pressure side of a manometer or sensitive pressure gauge (such as the IMPCO TG-010–include in ITK-1 tool kit) to the IMP sub-regulator output pressure port. 1) Turn off the fuel supply and slowly release the pressure in the fuel line. 1) Unscrew the dust cap on the IMP sub-regulator and maintain the engine at high idle. 2007 . then you will have to install a different spring. Adjusting the IMP Sub-Regulator: After the primary regulator is properly adjusted. Turn the pressure adjusting screw on the primary regulator until the appropriate meter/gauge reads 18-22” H2O column. 99 June. Replacing the IMP Sub-Regulator Spring: If you cannot adjust the IMP sub-regulator to 5” H2O column. 4) ©2007 IMPCO Technologies. Turn on the fuel supply and perform the 2-step IMP sub-regulator adjustment (see above). Reinstall the dust cap on the primary regulator. 2) Turn the IMP sub-regulator pressure adjusting screw until the appropriate meter/gauge reads 5” H2O column. Remove the spring and install the alternate spring (see figure #43). you can proceed to adjusting the IMP subregulator.4) Start the engine. 2) Unscrew the dust cap on top of the IMP sub-regulator. Figure #43 3) Reinstall the pressure adjusting screw and tighten it to about half way down the neck of the regulator. Inc. and run it at fast idle (rated speed. no load). Remove the pressure adjusting screw from the neck of the regulator by unscrewing it. spillage and evaporation Improved fuel system integrity Eliminates underground fuel storage concerns ©2007 IMPCO Technologies. LNG) 750–1. Gaseous Fuel Benefits: 1) 2) 3) 4) 5) 6) Reduced emissions Longer engine life Reduced maintenance cost Eliminates fuel pilferage.700 Biogas (Landfill & • Sewage and Waste Digester) Treatment Facilities Coal Seam Gas • Coal Fields 400. 100 June. Gaseous Fuel Types: Fuel Type Origin BTU per ft3 Common Usage • • • • • • • • • • • • • • • • • • • • • • Engine Fuel Co-generation Cooking Heating Water Heating Air Conditioning Clothes Dryers Engine Fuel Co-generation Cooking Heating Water Heating Air Conditioning Clothes Dryers Engine Fuel Co-generation Cooking Heating Water Heating Air Conditioning Clothes Dryers Stationary Engine Fuel • Co-generation • Stationary Engine Fuel • Co-generation Engine Applications • Automotive • Off-Road and Farm Vehicles • Material Handling • Industrial Engines • Automotive • Off-Road and Farm Vehicles • Material Handling • Industrial Engines • Automotive • Off-Road and Farm Vehicles • Material Handling • Industrial Engines • Industrial Engines • Industrial Engines Natural Gas • Gas Wells (NG.750 500-750 B.150 LPG • Light Crude Oil • Gasoline Extraction • Natural Gas 2.General Information A.500 Butane Gas • Light Crude Oil • Gasoline Extraction • Natural Gas 2. Inc. CNG. 2007 . Therefore.491 = 58.491: 23.015 0. Crankcase Oil Requirements: Always follow the engine manufacturer’s recommendations for oil type and change intervals. However. heat and pressure cause oil to deteriorate and it should be changed even though it looks clean. Pressure Conversion Chart: LPG and CNG are stored under high pressure.491 3.249 2.386 33. multiply the 23. it is very important to be familiar with the different types of pressure measurements used to test and troubleshoot problems with gaseous fuel systems. ©2007 IMPCO Technologies.100 10. The following chart reflects how the different pressure units relate to each other. These high pressures must be reduced before the fuel enters the engine.8 Millibars Inches of Water Column Inches of Water Column 1 Inches of Mercury Column 0.C. Multiply by the factor in the corresponding square.145 0. 2007 . the affects of friction.295 0.6 by 2.6 X 2. Inc.074 Pounds per Square Inch (PSI) 0. Find the unit of pressure you want to convert into in the columns on the top.7 1 0.864 Pounds per Square Inch (PSI) 27.68 2. 101 June.401 0. Chart Instructions: 1) 2) 3) Find the known unit of pressure in the rows on the left. Example: To convert 23. Oil used in gaseous-fueled engines may remain cleaner than oil in gasoline or diesel engines.036 1 6.895 68-948 Kilopascal (kPa) Millibar 4.491 Inches of Mercury Column 13.036 Kilopascal (kPa) Millibar 0.6 Inches of Water Column to Millibars.0 1 D.030 0.015 1 0. 01pr=100-18=82 ©2007 IMPCO Technologies. HP=100-q100o(240-60)I10po0. 5. As the air is heated. The displacement is fixed by the engine’s bore and stroke. it takes a larger volume to make up the seven pounds required to make the one HP.6oC) increase in temperature. As air temperature rises. A 100 CID 4-stroke engine can only push 100 cubic inches of air for every 2 revolutions of the crankshaft. This same engine will only make 82 HP breathing in air at 240oF. Inc.7 PSI. its density is reduced through expansion. The power output of an engine is calculated at 59oF (15oC) and a pressure of one atmosphere (14. This reduction in density decreases the volumetric efficiency of the engine with a resultant decrease in power output. it expands becoming lighter (like a hot air balloon). For every ten-degree Fahrenheit (10oF. An engine running at its rated full load rpm can only pump a fixed volume of air. Effects of Air Temperature on Power Output: The temperature of the air entering an engine is very important for two reasons: 1) Hot air entering an engine can cause detonation and pre-ignition.E. the better it is for the engine. This decrease in power output can be explained by the fact that an engine requires seven pounds of air to make one horsepower (HP) for one hour.sea level). 2) Example: An engine produces 100 HP breathing in air at 60oF. Since the air is now lighter. there is a one percent (1%) loss in the engine’s power output. The cooler the temperature of the engine’s incoming air. 102 June. which will damage or destroy an engine in short order. 2007 . F. Effects of Altitude on Power Output: The altitude at which an engine is operating has a dramatic effect on its power output. This has the same effect on power output as increasing temperature. As stated earlier.7 PSI. Inc. 2007 . As altitude increases. 103 June.sea level). Example: An engine that produces 100 HP at sea level will only produce 70 HP at 10. The rate of power output decrease is 3% for every 1. an engine’s power output is calculated at 59oF (15oC) and a pressure of one atmosphere (14.000 foot increase in altitude. the density of the air decreases due to less available atmosphere molecules (at sea level there is 14. decreasing with altitude).000 feet.7 pounds of air molecules pushing down on every square inch. HP=100-q100o10000I1000po0.03pr=100-30=70 ©2007 IMPCO Technologies. The manifold depression at 15.92” HG column atmospheric pressure minus 9” HG column manifold pressure will read 20. ©2007 IMPCO Technologies. 29. 2) 3) Manifold depression lessens at higher altitudes due to the lower density of the air at increasing altitudes. 2007 . NOTE: Refer to Correction Table for Altitude on page 133 for the standard manifold depression corrections at selected altitudes. 104 June.92” manifold depression on the HG manometer. Manifold depression (as measured with a mercury manometer) is the difference between 9” absolute pressure and atmospheric pressure.45”. Effects of Altitude on Intake Manifold Depression (Vacuum): 1) The Absolute Pressure produced in the intake manifold during the intake cycles of an engine is constant at approximately nine inches (9”) of mercury (HG) column above zero absolute pressure (with engine unloaded).000’ altitude is approximately 16.9” = 7.000’ is: 16. • Atmospheric pressure at 15. • At sea level.45” of HG column.G.45” HG column. Inc. 9 HP • • • 4) Natural Gas (NG) has an even higher displacement of air resulting in even more loss of power output.000 ft3 of air per hour would produce 999 HP. Propane weighs 0.6/1) by weight.34 ft3 total volume. gasoline produces 999 HP Propane produces 958 HP (4% air displacement) NG produces 921 HP (8% air displacement) ©2007 IMPCO Technologies.H. • • • • NG stoichiometric ratio is 17.076 (# air/ft3) = 24. Propane’s stoichiometric ratio by volume would then be: 15. • Propane’s stoichiometric (ideal) fuel ratio is 15. the power output for the same engine would be 921. an engine running on gasoline and consuming 92.1187 (# of propane) = 1. Air Displacement by Fuel (and the Effect On Power Output): 1) Diesel direct injection displaces no air due to the fuel being injected after all of the air is drawn into the engine during the intake cycle.34 parts air/1 part propane by volume. This is the ratio of air and fuel where all of the fuel and most of the oxygen (O2) is consumed in combustion resulting in the best performance with least emissions.85# of air.3 (ft3 air) + 1 (ft3 propane) = 24. Summary: In this example.000 (ft3 air) ÷ 24.076)] = 957. Also.1 HP running on NG.6 parts air to 1 part fuel (15.220 ft3 air • • Remembering an engine requires 7# of air to make 1 HP for one hour: 88.1 ft3 [volume of 7# of air (7 ÷ 0.85 (# air) ÷ 0. vaporization of gasoline cools the incoming air making it denser adding mass to the intake charge. The HP produced running the same engine on propane (due to the air displacement) would be: 24. 2007 .000 (ft3 air).052#/ft3 Using the same formulas. Inc. 1. NG weighs 0.1187 pounds (#) per cubic foot (ft3).34 (ft3 total) = 3780 ft3 propane 92. 2) Gasoline vapor displaces a minimal amount of air at full load since it is only partially vaporized as it enters the cylinder. Assuming negligible displacement of air by gasoline. 3) Propane enters the induction system as a vapor adding no cooling effect to the charge from vaporization. 92.6 (parts air) x 0.34 (ft3 of air) = 24.220 ÷ 92. 105 June.076# per ft3 (at sea level).3/1 by weight.3780 (ft3 propane) = 88. Air weighs 0. 7 PSI) at 59O Fahrenheit.Air-Terms and Measurement The condition of air is described by the terms: • • • • • • Atmospheric Pressure Absolute Pressure Pressure Differential Volume Weight and Density Gauge Pressure Atmospheric Pressure: This is the absolute pressure above a perfect vacuum at any geographic location or temperature. • • The atmospheric pressure at seal level is calculated to be 29. When the throttle valve is nearly closed (idle or deceleration). temperature or movement of atmospheric air masses will change this figure.92” Hg (atmospheric absolute) minus 9” Hg = 20. • Intake manifold depression (vacuum) is actually a measurement (in inches of mercury) between atmospheric pressure and absolute pressure within the manifold as produced by the air pumping action of the engine against the throttle valve. or about 4. Absolute Pressure: This is the actual pressure above a perfect vacuum (which is impractical to produce mechanically). then intake manifold depression is high.92” Hg (mercury).92” Hg manifold depression (vacuum). • ©2007 IMPCO Technologies. This is what you read on an intake manifold vacuum gauge. Pressure Differential: This is the difference between two pressures.92” of mercury column (14. it follows: 29.5 PSI above a perfect vacuum. 2007 . When the throttle valve is wide open (hard acceleration). Since the mean atmospheric pressure at sea level is 29. generally with reference to atmospheric pressure as one of the two. 106 June. and will be shown on a barometer (which registers in inches of mercury column). then intake manifold depression is low. Inc. Any change in altitude. Average absolute pressure obtainable inside the intake manifold of an unloaded engine is 9” of mercury. Inc.Volume: Volume is constant. • Since an engine of given displacement pumps air into cylinders of a constant size. being a measurement of space rather than a condition of air or gas. A supercharged engine also draws the same volume into the engine. The only difference between this condition and when the engine is at wide open throttle is the weight and density of the charge are less. 107 June. The same volume is drawn in per revolution. the volume of air and gas required to fill those cylinders is constant. with the weight and density of the charge being greater than a normally aspirated engine. When the carburetor throttle valve is closed (causing a high manifold depression or vacuum). the pistons continue to draw the same volume of air and gas into the cylinders. 2007 . In the IMPCO air valve carburetor. whether the engine is naturally aspirated or supercharged to several pounds above atmospheric pressure. there are more or less revolutions in the allotted time. ©2007 IMPCO Technologies. • The only change in total volume entering the cylinders occurs when rpm changes. the air valve opens in relation to throttle position the same distance. however. Consequently. the average weight of natural gas is: 0. The denser the mass is (within practical limits). Natural Gas Properties (Average): The average weight of natural gas (compared to air) is a product of the specific gravity of natural gas (0.0.076 lb/ft3 = 0. more generally.21 ft3 oxygen @ 59O F and 29. The same tank of air pressurized to 1000 PSI contains a more dense mass of air. the more power will be produced when the charge is ignited. Weighs approximately 0.695 x 0. the charge becomes denser as the piston compresses it. 108 June. The . 2007 .Weight and Density of Air: • Weight and density of air of a given volume vary proportionally with pressure.0695 (specific gravity) times the weight of air is constant with altitude change (assuming air and gas temperature remain constant). An air receiver tank filled with air at atmospheric pressure will float on water. 1 ft3 of air contains 0. • • By this formula. ©2007 IMPCO Technologies. the charge becomes heavier per cubic inch of volume when compressed. Weight and density of the charge introduced into the cylinder during the intake cycle directly affects the density of the charge upon compression.695) times the weight of air (at a given temperature and pressure).042 lb/ft3 @ 15.92” Hg pressure. the air/fuel ratio remains constant from sea level to high altitude. Inc. Therefore. During the compression cycle of an engine. The specific gravity of air is 1. it can be compressed to a higher degree to reach practical limits of density when ignited.0528 lb/ft3 @ 59O F and 29. and the increased weight will cause it to sink. Weighs approximately 0. Weighs 3% less with each 1000 feet above sea level.076 lb/ft3 @ 59O F and 29. A higher compression ratio may be used at high altitude. Weighs 1% less for each 10O above 59O F. a measurement above or below atmospheric pressure (as indicated on the vacuum gauge connected to the intake manifold).92” Hg pressure. while total weight of the charge drawn into a cylinder does not increase.0714 lb/ft3 @ 120O F.000 feet altitude. Since the air/fuel mass drawn into the cylinder weighs less. • • • Gauge Pressure: This can be absolute pressure (as indicated on a barometer) or. Air Properties: • • • • • • Weighs 0.92” Hg pressure. ©2007 IMPCO Technologies.902).The BTU (British Thermal Unit) content of natural gas varies considerably from region-toregion and from producing field-to-producing field (within a region).902 (LHV = HHV x 0. It represents all of the potential heat in a cubic foot of gas. Inc. Horsepower (as it relates to BTU Consumption): Horsepower can be defined as: 2545 BTU’s to make one horsepower for one hour (1 HP/Hr = 2545 BTU).076 lb/ft3 = 0. (The specific gravity of air is 1. Low heat value (LHV) is the actual heat in BTU’s/ft3 available to do work. Some regional natural gas BTU contents are: • • • • • • Texas (some fields)-High heat value of 742 BTU’s/ft3.5617 x 0. Pennsylvania-High heat value of 1228 BTU’s/ft3.92” Hg pressure. the 1. • • By this formula. High heat value (HHV) is the total amount of heat available in BTU’s/ft3 as measured by a calorimeter. Wisconsin-High heat value of 987 BTU’s/ft3. the weight of propane vapor is: 1. Propane Properties (Vapor): The weight of propane vapor (compared to air) is a product of the specific gravity of propane (1. The low heat value is the high heat value times 0. However. 2007 . The difference is the BTU’s/ft3 used in the chemical reactions necessary to convert the air and gas into its combustion components (such as water and carbon dioxide).5617 (specific gravity) times the weight of air is constant with altitude change (assuming air and gas temperature remain constant). This is a very useful tool for determining regulator and fuel delivery pipe sizing.0). As with natural gas. For an engine to produce one horsepower for one hour.1187 lb/ft3 @ 59O F and 29.000 BTU’s.5617) times the weight of air (at a given temperature and pressure). most of the available BTU’s in the fuel are wasted as heat exiting the exhaust. 109 June. Therefore. Oklahoma-High heat value of 1023 BTU’s/ft3. the air/fuel ratio remains constant from sea level to high altitude. it consumes approximately 10. 600VF3 600VF3 600VF3DX-1. Inc. 600VF3DX-1-2. DG600VF3DX-1-2 600VF3DX-1 600VF3DX-1. 600VF3DX-1-2. 2007 . 600VF3 600VF3 NG600VF3DX-6-2. NG600VF3D-9-2 600VF3DX-1 400VF3X-1-2 400VF3X-3-2 400VF3X-1-2 400VF3X-3-2 Caterpillar Cooper. 110 June. 600VF3-125 ©2007 IMPCO Technologies.Superior Cummins Cummins (Natural Gas) 600VF3 600VF3 w/T2-7.IMPCO VARIFUEL Carburetor Application by Engine Manufacturer ENGINE MANUFACTURER ENGINE MODEL G379 G397 G398 G398 TA G399 TA G3406 G3408 G3412 G3508 G3512 G3516 G3520 6G-825 6GT-825 8G-825 8GT-825 L10-230 L10-240NG G12/G-743 GTA12/GTA743A GTA14 GTA855A GTA855B GTA19/GTA1150 GTA28/GTA1710 IMPCO VARIFUEL CARBURETOR 400VF3U-1-2 400VF3X-1-2 400VF3X-3-2 NG400VF3X-3-2 NG600VF3X-8-2 w/A2-27 400VF3. 111 June.ENGINE MANUFACTURER ENGINE MODEL PVG-6 SVG-8 SVG-10 SVG-12 KVG-10 KVG-12 KVS-6 KVS-12 48KVG 410KVGB 412KVGR 412KVS 12V-AT25GL 12V-AT27GL 8L-AT27GL F1197G F817G VFG F18G VFG F18GL VFG F18GLD VFG H24G VFG H24GL VFG H24GLD VFG L36GL VFG L36GLD VFG P48GL VFG P48GLD VHP 2895 VHP 3521 IMPCO VARIFUEL CARBURETOR 600VF3DX-3-2 600VF3DX-3-2 600VF3DX-5-2 Ingersoll-Rand 600VF3DX-3-2 600VF3 400VF3 400VF3U-1-2 400VF3 400VF3U-3-2 400VF3 Waukesha 600VF3 400VF3 600VF3 ©2007 IMPCO Technologies. Inc. 2007 . 2007 . Inc. 112 June.ENGINE MANUFACTURER ENGINE MODEL F3521GSI VHP 5108 VHP 5790 L5790GSI 5790GL VHP 7042 VHP 9390 P9390GSI VSG F11G VSG F11GSI/GSID IMPCO VARIFUEL CARBURETOR 600VF3U 600VF3U (2X) 600VF3DU (2X) 600VF3DX (2X) 600VF3DX (4X) 400VF3U-1-2 400VF3U-3-2 Waukesha ©2007 IMPCO Technologies. Large Engine Application Information Worksheet (Complete and forward to your local distributor) Name: Company: Location: Engine Manufacturer: Displacement: Configuration: Inline one) Rated Speed: Aspiration: Normal Stoichiometric Vee Date: Telephone: Fax: Model: Year: Liters (check one) # of Cylinders: 4-Cycle BHP (check one) Ignition Type: Throttle Body Bolt Ctr. Inc. 2007 . (check one) rpm Turbocharged Rated Power Supercharged Lean Burn (check one) (check one) Type: SAE Flange Size: AFC Installed: Yes No Carburetor: Model # Fuel Type: NG LPG Digester Land Fill (check one) Known Contaminants: Minimum Fuel Pressure @ Carburetor (Engine @ Full Load): Minimum Fuel Pressure @ Carburetor (Engine not Running): Engine Location: Engine Application: Generator Compressor Pump Other NOTES: (check one) IMPCO: Carburetor: Mixer: Gas Inlet Module: Mixture Outlet Module (Throttle Body): Air Inlet Module (Air Horn) Adapters: Written By: Gas Conversion Kit: Pressure Regulator: Pressure Sub-Regulator: Accessories/Options: ©2007 IMPCO Technologies. 113 June. BTU: 2-Cycle KW (check (check one) Cubic In. They support a wide array of functions making them extremely versatile. yet very convenient and easy to use pressure measurement tool. It can and should be used to measure or calibrate other face type gauges. add the number of inches one column travels up to he amount the other column travels down. It is designed to measure slight positive and negative pressures. vacuum or differential pressure according to the manufacturer’s instructions. 114 June. Inc. 2007 . Figure #44 Figure #45 ©2007 IMPCO Technologies. digital manometers are very accurate. While pressure is applied. Electronic Manometer (Figure #45): Electronic. but more costly than a U-tube manometer. Follow the manufacturer’s instructions for use on these types of meters.Test Equipment/Tools U-Tube Manometer: The U-tube manometer is a highly accurate. Taking a reading: • • Connect the manometer to the source of pressure. • G2-2 Lever Gauge: For correct adjustment of the IMPCO pressure regulator. primary pressure. The kit contains the following: • 0-200 PSI Gauge: For measuring fuel container pressure or (on dual fuel systems) it may be used to measure gasoline fuel system pressure. • Assorted Fittings • Hose • Instructions Figure #46 ©2007 IMPCO Technologies.IMPCO ITK-1 Test Kit: The IMPCO ITK-1 test kit is designed for testing and troubleshooting IMPCO gaseous fuel systems. secondary pressure. 2007 . • 0-5 PSI Gauge: For measuring IMPCO pressure regulator. 115 June. • 0-10” H2O Column Gauge: For measuring IMPCO pressure regulator. Inc. secondary lever. Inc. It is used for measuring various types of electrical signals. adjustable sample rates. The use of a Fluke™ or equivalent DVOM is highly recommended for their reliability and accuracy. This is the only empirical way to ensure adherence to emission requirements. • Figure #48 ©2007 IMPCO Technologies. 116 June. solid state circuits) Very accurate Filtered. Figure #47 Digital Volt and Ohm Meter (DVOM): The DVOM is a standard and essential diagnostic tool.Gas Exhaust Gas Analyzer: IMPCO recommends the use of a 5-gas exhaust gas analyzer (such as the Infrared Industries FGA5000). Some important characteristics of a DVOM are: • • High-impedance (safe for sensitive. 2007 . 915 cubic inches The power of 10-2 indicates moving the decimal point two places to the left (or minus side) of the result.48 x 104 = 424. to transpose it to a desired equivalent unit and quantity. the following table of conversion factors is expressed entirely as multiplication of a known unit and quantity. 117 June. Multiply 15 Cubic Feet By 2. Inc.Conversion Factors Powers of Ten: For simplification. 2007 . and to assist in the proper placement of the decimal point in the result.1 x 10-2 = cubic inches 91. The powers of ten are used to reduce the length of unwieldy numbers. ©2007 IMPCO Technologies.5 x 10-2 = 0.832 x 104 = cubic centimeters 42. Examples: Multiply 15 Cubic Centimeters By 6.800 cubic centimeters The power of the 104 indicates moving the decimal point 4 places to the right (or plus side) of the results.10 x 10-2 To Obtain Cubic Inches 15 x 6.832 x 104 To Obtain Cubic Centimeters 15 x 2. 52 109 9x1020 39364 39361 1/9x10-20 1.662x102 103 39370 39358 39364 1/9x10-20 39358 6.0155 0.38 4840 39092 6.4 10 3x1010 64.52 10 12. 118 June.257 2.015x10-3 1/3x10-10 39363 43560 3.155 4.259x105 43560 4047 1.54 0.02471 To Obtain Amperes Statamperes Amperes per sq inch Ampere-turns Gilberts Ampere-turns per inch Coulombs Statcoulombs Coulombs per sq inch Farads Statfarads Henries Millihenries Stathenries Mhos per mil foot Megmhos per cm cube Megohms microhms Ohms Statohms Micohms per cm cube Ohms per mil foot Statvolts Volts Cubic feet Gallons Square feet Square meters Square miles Square varas Square yards Abamperes Amperes per sq inch Abamperes per sq cm Amperes per sq cm Statamperes per sq cm Abampere-turns Gilberts Ampere-turns per inch Abampere-turns per cm Ampere-turns per cm Gilberts per cm Newton Centimeters Acres ©2007 IMPCO Technologies.562x10-3 5645.57 25. 2007 . Inc.03937 0.453 0.Conversion Table Multiply Abamperes Abamperes Abamperes per sq cm Abampere-turns Abampere-turns Abampere-turns per cm Abcoulombs Abcoulombs Abcoulombs per sq cm Abfarads Abfarads Abhenries Abhenries Abhenries Abmhos per cm cube Abmhos per cm cube Abohms Abohms Abohms Abohms Abohms per cm cube Abohms per cm cube Abvolts Abvolts Acre-feet Acre-feet Acres Acres Acres Acres Acres Amperes Amperes per sq cm Amperes per sq inch Amperes per sq inch Amperes per sq inch Ampere-turns Ampere-turns Ampere-turns per cm Ampere-turns per inch Ampere-turns per inch Ampere-turns per inch Amp-weber/meter Angstrom unit Ares By 10 3x10-10 64.3937 0.650x108 39092 1.495 1 39363 0. 92 Approx.244 2150 0.899 12. Inc.01316 0.3937 0.7 10 108 0.5 144 0.239 1 0. 1 14.88 1.333 14.96 0.927x10-4 1054 107.5 3.5556 2.01 0.01 1.57 0.122 4.376x10-8 980.4461 To Obtain Square meters Feet of water Kg per sq meter Pounds per sq inch Tons per sq foot Cms of mercury Inches of mercury Kilowatt-hours Pounds per sq inch Cubic inches Kilogram-calories Foot-pounds Horsepower-hours Joules Kilogram-meters Kilowatt-hours Kg-cal per cu meter Foot-pounds per sec Horsepower Kilowatts Watts Kg-cal per kg Kg-cal per sq meter Watts per sq inch Kg-cal/(hr)(sq m)(deg C) Cubic feet Cubic inches Cubic meters Pecks Pints (dry) Quarts (dry) Joule Sq meters Grams Liters Centimeter-grams Meter-kilograms Pound-feet Centimeter-dynes Meter-kilograms Pound-feet Inches Meters Mils Millimeters Angstrom unit Atmospheres Feet of water ©2007 IMPCO Technologies.02356 0.7 1.01 393.253 777.01757 17.Multiply Ares Atmospheres Atmospheres Atmospheres Atmospheres Atmospheres Atmospheres Average noon sunlight on 1 sq meter Bar Board-feet British thermal units British thermal units British thermal units British thermal units British thermal units British thermal units BTU per cu ft BTU per min BTU per min BTU per min BTU per min BTU per pound BTU per sq ft BTU per sq ft per min BTU/(hr)(sq ft)(deg F) Bushels Bushels Bushels Bushels Bushels Bushels Calorie Centares Centigrams Centiliters Centimeter-dynes Centimeter-dynes Centimeter-dynes Centimeter-grams Centimeter-grams Centimeter-grams Centimeters Centimeters Centimeters Centimeters Centimeters Centimeters of mercury Centimeters of mercury By 100 33.5 2.233x10-5 0.928x10-4 8.9 10.712 0.03524 4 64 32 0.7 39360 7.020x10-8 7. 119 June. 2007 .058 76 29.020x10-3 1. 02832 0.39 5.03281 0.Multiply Centimeters of mercury Centimeters of mercury Centimeters of mercury Centimeters per second Centimeters per second Centimeters per second Centimeters per second Centimeters per second Centimeters per second Circular mils Circular mils Circular mils Cm per sec per sec Cm per sec per sec Cm per sec per sec Cords Coulombs Coulombs Coulombs per sq inch Coulombs per sq inch Coulombs per sq inch Cubic centimeters Cubic centimeters Cubic centimeters Cubic centimeters Cubic centimeters Cubic centimeters Cubic centimeters Cubic centimeters Cubic feet Cubic feet Cubic feet Cubic feet Cubic feet Cubic feet Cubic feet Cubic feet Cubic ft per minute Cubic ft per minute Cubic ft per minute Cubic ft per minute Cubic inches Cubic inches Cubic inches Cubic inches Cubic inches Cubic inches Cubic inches By 136 27.155 4.531x10-5 6. 120 June.7854 0.278x10-4 5.03281 0.639x10-5 To Obtain Kg per sq meter Pounds per sq foot Pounds per sq inch Feet per minute Feet per second Kilometers per hour Meters per minute Miles per hour Miles per minute Sq centimeters Sq inches Sq mils Feet per sec per sec Km per hour per sec Miles per hour per sec Cubic feet Abcoulombs Statcoulombs Abcoulombs per sq cm Coulombs per sq cm Statcoulombs per sq cm Cubic feet Cubic inches Cubic meters Cubic yards Gallons Liters Pints (liq) Quarts (liq) Cubic cms Cubic inches Cubic meters Cubic yards Gallons Liters Pints (liq) Quarts (liq) Cubic cm per sec Gallons per sec Liters per sec Lb of water per min Gallons Liters Pints (liq) Quarts (liq) Cubic centimeters Cubic feet Cubic meters ©2007 IMPCO Technologies.329x10-3 1.650x10-5 3.057x10-3 2.4 4.642x10-4 39358 2. 2007 .1247 0.854x10-7 0.03704 7.113x10-3 1.0155 0.6 0.10x10-2 39361 1.308x10-6 2.481 28.639x10-2 0.85 0.036 0.036 0.1924 1.84 29.92 472 0.969 0.03463 0.832x104 1728 0.067x10-4 7.02237 3.32 59.787x10-4 1.01732 16.472 62.02237 128 39092 3x108 0. Inc. 646x105 27 46656 0.020x10-3 To Obtain Cubic yards Cubic centimeters Cubic feet Cubic inches Cubic yards Gallons Liters Pints (liq) Quarts (liq) Cubic centimeters Cubic feet Cubic inches Cubic meters Gallons Liters Pints (liq) Quarts (liq) Cubic ft per sec Gallons per sec Liters per sec Hours Minutes Seconds Meters Grams Liters Meters Minutes Radians Seconds Radians per sec Revolutions per min Revolutions per sec Grams Liters Area of a circle Area of a sphere Grams Ounces Newtons Grams Poundals Pounds Bars BTUs Dyne-centimeters Foot-pounds Gram-centimeters ©2007 IMPCO Technologies.1667 0.01745 0.7854 3.367 12. 121 June.Multiply Cubic inches Cubic meters Cubic meters Cubic meters Cubic meters Cubic meters Cubic meters Cubic meters Cubic meters Cubic yards Cubic yards Cubic yards Cubic yards Cubic yards Cubic yards Cubic yards Cubic yards Cubic yards per min Cubic yards per min Cubic yards per min Days Days Days Decameters Decigrams Deciliters Decimeters Degrees (angle) Degrees (angle) Degrees (angle) Degrees per sec Degrees per sec Degrees per sec Dekagrams Dekaliters Diameter squared Diameter squared Drams Drams Dynes Dynes Dynes Dynes Dynes per sq cm Ergs Ergs Ergs Ergs By 2. Inc.1 0.2 103 2113 1057 7.7646 202 764.31 61023 1308 264.48x10-11 1 7.74 24 1440 86400 10 0.0625 39360 1. 2007 .143x105 106 35.002778 10 10 0.772 0.6 1616 807.376x10-8 1.9 0.45 3.1 0.248x10-6 1 9.1 60 0.233x10-5 2.020x10-3 7.01745 3600 0.1416 1. 508 0.36 39085 0.43 0.01136 30.3048 0.8826 304.01136 30.766x10-7 1.356 3.3048 0.241x10-4 1.692x10-9 4.0295 0.286x10-3 1.8 62.48 1.097 18.1383 3. Inc.01667 3.48 12 0.376x10-8 1.020x10-8 5.356x107 5.097 0.29 0.434x10-9 39365 39364 106 9x10-11 6 30.6818 0.3048 0.426x10-6 7.030x10-5 To Obtain Joules Kilogram-calories Kilogram-meters BTU per min Foot-pounds per min Foot-pounds per sec Horsepower Kg-calories per min Kilowatts Abfarads Microfarads Statfarads Feet Centimeters Inches Meters Varas Yards Atmospheres Inches of mercury Kg per sq meter Pounds per sq ft Pounds per sq inch Per cent grade Centimeters per sec Feet per sec Kilometers per hr Meters per min Miles per hr Centimeters per sec Kilometers per hr Meters per min Miles per hr Miles per min Cm per sec per sec Cm per sec per sec Meters per sec per sec Miles per hr per sec Kilogram-meters Kilowatt-hours British Thermal Units Ergs Horsepower-hrs Joules Kilogram-calories BTU per min Foot-pounds per sec Horsepower ©2007 IMPCO Technologies.6818 0.39x10-11 1. 122 June.01667 0.48 1.341x10-10 1.050x10-7 1.286x10-3 0.4335 1 0. 2007 .Multiply Ergs Ergs Ergs Ergs per sec Ergs per sec Ergs per sec Ergs per sec Ergs per sec Ergs per sec Farads Farads Farads Fathoms Feet Feet Feet Feet Feet Feet of water Feet of water Feet of water Feet of water Feet of water Feet per 100 feet Feet per min Feet per min Feet per min Feet per min Feet per min Feet per sec Feet per sec Feet per sec Feet per sec Feet per sec Feet per sec per sec Feet per sec per sec Feet per sec per sec Feet per sec per sec Foot-pounds Foot-pounds Foot-pounds Foot-pounds Foot-pounds Foot-pounds Foot-pounds Foot-pounds per min Foot-pounds per min Foot-pounds per min By 39362 2.01829 0. 600x10-3 62.7 15.118 3.06308 6.951x10-3 3.03613 3.7 7.43 0.302x10-8 980.968x10-3 9.228x10-3 0.0648 0.Multiply Foot-pounds per min Foot-pounds per min Foot-pounds per sec Foot-pounds per sec Foot-pounds per sec Foot-pounds per sec Furlongs Gallons Gallons Gallons Gallons Gallons Gallons Gallons Gallons Gallons per min Gallons per min Gausses Gilberts Gilberts Gilberts per centimeter Gills Gills Grains (troy) Grains (troy) Grains (troy) Grains/US gallon Gram-calories Gram-centimeters Gram-centimeters Gram-centimeters Gram-centimeters Gram-centimeters Gram-centimeters Grams Grams Grams Grams Grams Grams Grams Grams Grams per cm Grams per cu cm Grams per cu cm Grams per cu cm Hectares Hectares By 3.07958 0.717x10-2 1.25 1 0.03215 0.1337 231 3.07093 2.43 39358 103 0.076x105 To Obtain Kg-calories per min Kilowatts BTU per min Horsepower Kg-calories per min Kilowatts Rods Cubic centimeters Cubic feet Cubic inches Cubic meters Cubic yards Liters Pints (liq) Quarts (liq) Cubic feet per sec Liters per sec Lines per sq inch Abampere-turns Ampere-turns Ampere-turns per inch Liters Pints (liq) Grains (av) Grams Pennyweights (troy) Parts per million BTUs BTUs Ergs Foot-pounds Joules Kilogram-calories Kilogram-meters Dynes Grains (troy) Kilograms Milligrams Ounces Ounces (troy) Poundals Pounds Pounds per inch Pounds per cu foot Pounds per cu inch Pounds per mil-foot Acres Sq feet ©2007 IMPCO Technologies.7958 2.233x10-5 9.452 0.471 1.785 8 4 2.356x10-3 40 3785 0.405x10-7 2.205x10-3 5.241x10-4 2.807x10-5 2. 123 June.945x10-2 1.260x10-5 7.785x10-3 4.03527 0.344x10-8 39360 980.021 0. 2007 . Inc.818x10-3 1.04167 17.1183 0. 03 1.7457 745.3 70.7457 60 3600 2540 103 0.014 10.002458 0.73 0.684x106 641.44 33000 550 1.03613 0.5 4 6.283 109 103 1/9x10-11 42.Multiply Hectograms Hectoliters Hectometers Hectowatts Hemispheres (solid angle) Hemispheres (solid angle) Hemispheres (solid angle) Henries Henries Henries Horsepower Horsepower Horsepower Horsepower Horsepower Horsepower Horsepower Horsepower (boiler) Horsepower (boiler) Horsepower-hours Horsepower-hours Horsepower-hours Horsepower-hours Horsepower-hours Horsepower-hours Hours Hours Inches Inches Inches Inches of Hg Inches of Hg Inches of Hg Inches of Hg Inches of mercury (Hg) Inches of water Inches of water Inches of water Inches of water Inches of water Inches of water Joule Joule per sec Joule/sq amp sec Joules Joules Joules Joules By 100 100 100 100 0.7 2.07355 25.7376 2.184 1 1 9.98x106 2.133 345.486x10-4 107 0.390x10-4 To Obtain Grams Liters Meters Watts sphere Spherical right angles Steradians Abhenries Millihenries Stathenries BTU per min Foot-pounds per min Foot-pounds per sec Horsepower (metric) Kg-calories per min Kilowatts Watts BTU per hr Kilowatts BTUs Foot-pounds Joules Kilogram-calories Kilogram-meters Kilowatt-hours Minutes Seconds Centimeters Mils Varas Feet of water Kg per sq meter Pounds per sq ft Pounds per sq in Atmospheres Pounds per sq foot Pounds per sq in (PSI) Atmospheres Inches of mercury Kg per sq meter Ounces per sq inch Calorie Watts Ohm BTUs Ergs Foot-pounds Kilogram-calories ©2007 IMPCO Technologies.4 0.03342 5.4912 0. 124 June.737x105 0. 2007 .7 0.5781 4. Inc.204 0.7 33520 9804 2547 1. 102x10-3 103 103 105 3281 103 To Obtain Kilogram-meters Watt-hours Newton meters Watt-sec Volt-coulomb Grams per cu cm Pounds per cu foot Pounds per cu inch Pounds per mil-foot Pounds per foot atmospheres Bars Feet of water Inches of mercury Pounds per sq foot Pounds per sq inch Kg per sq meter BTU per cu foot BTU per pound BTU per sq foot Foot-pounds per sec Horsepower Kilowatts Pounds-feet squared Pounds-inch squared Newton BTUs Foot-pounds Horsepower-hours Joules Kilogram-meters Kilowatt-hours BTUs Ergs Foot-pounds Joules Kilogram-calories Kilowatt-hours Dynes Grams Poundals Pounds Tons (short) Maxwells Liters Centimeters Feet Meters ©2007 IMPCO Technologies.778x10-4 1 1 1 39358 0.06243 3.07 3.43 0.724x10-6 980665 103 70.281x10-3 2.102 2.405x10-10 0.06972 2.302x10-3 9.8 0.678x10-5 98.162x10-3 9.3688 51.233 9. 125 June.896x10-3 0.672 9.344x10-3 2. 2007 .2046 1.807 2.422x10-3 106 0.556x10-3 4183 426.3417 1 3. Inc.968 3086 1.93 2.613x10-5 3.807x107 7.6 1.2048 1.Multiply Joules Joules Joules Joules Joules Kg per cu meter Kg per cu meter Kg per cu meter Kg per cu meter Kg per meter Kg per sq meter Kg per sq meter Kg per sq meter Kg per sq meter Kg per sq meter Kg per sq meter Kg per sq millimeter Kg-cal/cu meter Kg-cal/kg Kg-cal/sq meter Kg-calories per min Kg-calories per min Kg-calories per min Kg-cm squared Kg-cm squared Kg-meter/sq second Kilogram-calories Kilogram-calories Kilogram-calories Kilogram-calories Kilogram-calories Kilogram-calories Kilogram-meters Kilogram-meters Kilogram-meters Kilogram-meters Kilogram-meters Kilogram-meters Kilograms Kilograms Kilograms Kilograms Kilograms Kilolines Kiloliters Kilometers Kilometers Kilometers By 0.09351 0.373x10-3 0.1124 1. 057 103 5. 2007 .853 1.4343 2.Multiply Kilometers Kilometers Kilometers per hr Kilometers per hr Kilometers per hr Kilometers per hr Kilometers per hr Kilometers per hr Kilometers per min Kilowatt-hours Kilowatt-hours Kilowatt-hours Kilowatt-hours Kilowatt-hours Kilowatt-hours Kilowatt-hours Kilowatts Kilowatts Kilowatts Kilowatts Kilowatts Kilowatts Km per hr per sec Km per hr per sec Km per hr per sec Km per hr per sec Knots Knots Knots Knots Lines per sq cm Lines per sq inch Links (engineer's) Links (surveyor's) Liters Liters Liters Liters Liters Liters Liters Liters Liters per min Liters per min Log/e N or In N Log10 N Lumens per sq ft Maxwells By 0.341 14.6 27.425x104 737.155 12 7.152 2027 1 0.6 1.67x105 56.6214 6080 1.03531 61.113 1.92 0.9113 0.303 1 39358 To Obtain Miles Yards Centimeters per sec Feet per min Feet per sec Knots Meters per min Miles per hr Kilometers per hr Average noon sunlight on 1 sq meter BTUs Foot-pounds Horsepower-hours Joules Kilogram-calories Kilogram-meters BTU per min Foot-pounds per min Foot-pounds per sec Horsepower Kg-calories per min Watts Cm per sec per sec Ft per sec per sec Meters per sec per sec Miles per hr per sec Feet per hr Kilometers per hr Miles per hr Yards per hr Gaus Gaus Inches Inches Cubic feet Cubic inches (=dm3) Cubic meters Cubic yards Gallons Pints (liq) Quarts (liq) Cubic cm Cubic ft per sec Gallons per sec Log10 N Log/e N or In N Foot-candles Kilolines ©2007 IMPCO Technologies.68 0.02 39358 1. 126 June.2778 0.403x10-3 0.6214 1093.2642 2.92 4.78 54. Inc.5 3.78 0.308x10-3 0.655x106 1. 1 3415 2.5396 16.67 0.6x105 860.9113 0.886x10-4 4.34 103 27.6214 60 Appox.341 3. 281 0.1662 0.28 9.03728 3.281 3.667 3.03728 1968 3.06 2.870x10-7 1 0.281 6 0. 2007 .237 6.237 0.3937 6.807x107 105 7.54 0.37 39358 103 1.015x10-3 6.0102 2.2808 39.015 15.089x10-3 1. 127 June.06 0.6 2.3937 106 9.450x10-5 39370 39361 9x105 39361 103 39367 39361 1/9x10-17 103 0.Multiply Megalines Megmhos per cm cube Megmhos per cm cube Megmhos per cm cube Megmhos per inch cube Megohms Meter-kilograms Meter-kilograms Meter-kilograms Meters Meters Meters Meters Meters Meters Meters per min Meters per min Meters per min Meters per min Meters per min Meters per sec Meters per sec Meters per sec Meters per sec Meters per sec Meters per sec Meters per sec per sec Meters per sec per sec Meters per sec per sec Mhos per mil foot Mhos per mil foot Mhos per mil foot Microbars Microbars Microbars Microbars Microbars Microfarads Microfarads Microfarads Micrograms Microhms Microhms Microhms Microhms Microhms per cubic cm Microhms per cubic cm Microhms per cubic cm By 106 39358 2. Inc.015 To Obtain Maxwells Abmhos per cm cube Megmhos per in cube Mhos per mil ft Megmhos per cm cube Ohms Centimeter-dynes Centimeter-grams Pound-feet Centimeters Feet Inches Kilometers Millimeters Yards Centimeters per sec Feet per min Feet per sec Kilometers per hr Miles per hr Feet per min Feet per sec Kilometers per hr Kilometers per min Miles per hr Miles per min Feet per sec per sec Km per hr per sec Miles per hr per sec Abmhos per cm cube Megmhos per cm cube Megmhos per in cube Atmoshpheres Dynes per sq cm Kg per sq meter Pounds per sq foot Pounds per sq inch Abfarads Farads Statfarads Grams Abohms Megohms Ohms Statohms Abohms per cubic cm Microhms per cubic in Ohms per mil foot ©2007 IMPCO Technologies.233 100 3.0936 1.05468 0. 1 0.54 39361 39361 1. Inc.82 44.6093 60 14.6093 0.5x10-3 39358 106 1/9x10-14 39358 0. 128 June.8 44.447 2682 88 1.609x105 5280 1.03937 39.8684 26.467 1.6093 1760 1900.Multiply Microhms per cubic in Microliters Microns Miles Miles Miles Miles Miles Miles per hr Miles per hr Miles per hr Miles per hr Miles per hr Miles per hr Miles per hr per sec Miles per hr per sec Miles per hr per sec Miles per hr per sec Miles per min Miles per min Miles per min Miles per min Millibars Milligrams Millihenries Millihenries Milliliters Millimeters Millimeters Millimeters Mils Mils Miner's inches Minutes (angle) Minutes (angle) Months Months Months Months Myriagrams Myriameters Myriawatts Newton Newton Newton meters Newton-meter/amp Newtons Newtons By 2.909x10-4 60 30.5 2.00254 1.7 88 1.37 39358 0.7 1.467 1. 2007 .42 730 43800 2.6093 0.628x106 10 10 10 1 1 1 1 1.355 105 To Obtain Microhms per cubic cm Liters Meters Centimeters Feet Kilometers Yards Varas Centimeters per sec Feet per min Feet per sec Kilometers per hr Knots Meters per min Cm per sec per sec Feet per sec per sec Km per hr per sec Meters per sec per sec Centimeters per sec Feet per sec Kilometers per min Miles per hr Pounds per sq inch Grams Abhenries Stathenries Liters Centimeters Inches Mils Inches Centimeters Cubic ft per min Radian Seconds (angle) Days Hours Minutes Seconds Kilograms Kilometers Kilowatts Amp-weber/meter Kg-meter/sq sec Joules Weber Pound-feet Dynes ©2007 IMPCO Technologies. 555 0.6 16 32.Multiply Ohm Ohms Ohms Ohms Ohms Ohms per mil foot Ohms per mil foot Ohms per mil foot Ounces Ounces Ounces Multiply Ounces Ounces (fluid) Ounces (fluid) Ounces (troy) Ounces (troy) Ounces (troy) Ounces (troy) Ounces per sq inch Parts per million Pennyweights (troy) Pennyweights (troy) Pennyweights (troy) Perches (masonry) Pints (dry) Pints (liq) Poundals Poundals Poundals Pound-feet Pound-feet Pound-feet Pound-feet Pounds Pounds Pounds Pounds Pounds Pounds (troy) Pounds of water Pounds of water Pounds of water Pounds of water per min Pounds per cubic ft Pounds per cubic ft Pounds per cubic ft Pounds per cubic ft By 1 109 39361 106 1/9x10-11 166.06524 8 437.01602 16.05 24.02 5.68 0.17 0. 129 June.805 0.5 28.2 0.1 20 0.6 28.787x10-4 5.87 13826 14.01602 27.738 444823 7000 453.0625 1.75 33. Inc.35 By 0.1383 0.03108 1.08333 0.1198 2.0625 0.1 0.1662 0.456x10-9 To Obtain Joule/sq amp sec Abohms Megohms Microhms Statohms Abohms per cubic cm Microhms per cubic cm Microhms per cubic in Drams Grains Grams To Obtain Pounds Cubic inches Liters Grains (troy) Grams Pennyweights (troy) Pounds (troy) Pounds per sq inch Grains/US gallon Grains (troy) Grams Ounces (troy) Cubic feet Cubic inches Cubic inches Dynes Grams Pounds Centimeter-dynes Centimeter-grams Meter-kilograms Newtons Dynes Grains Grams Ounces Poundals Pounds (av) Cubic feet Cubic inches Gallons Cubic ft per sec Grams per cubic cm Kg per cubic meter Pounds per cubic in Pounds per mil foot ©2007 IMPCO Technologies.669x10-4 0.02957 480 31.356x107 13825 0.0584 24 1. 2007 .8229 0. Multiply Pounds per cubic in Pounds per cubic in Pounds per cubic in Pounds per cubic in Pounds per ft Pounds per in Pounds per mil foot Pounds per sq ft Pounds per sq ft Pounds per sq ft Pounds per sq in (PSI) Pounds-ft squared Pounds-ft squared Pounds-inches squared Pounds-inches squared PSI PSI PSI PSI Quadrants (angle) Quadrants (angle) Quadrants (angle) Quarts (dry) Quarts (liq) Quintals Quires Radians Radians By 27.3 144 2. 2007 .571 67.306x106 0.3 3438 To Obtain Grams per cubic cm Kg per cubic meter Pounds per cubic ft Pounds per mil foot Kg per meter Grams per cm Grams per cubic cm Feet of water Kg per sq meter Pounds per sq in Atmospheres Kg-cm squared Pounds-in squared Kg-cm squared Pounds-ft squared Feet of water Inches of mercury Kg per sq meter Pounds per sq ft Degrees Minutes Radians Cubic inches Cubic inches Pounds Sheets Degrees Minutes ©2007 IMPCO Technologies.488 178.6 2.01602 4.68 2.882 6. Inc.945x10-3 2.425x10-6 1.06804 421.307 2.2 57.768x104 1728 9.1 144 90 5400 1. 130 June.944x10-3 0.75 100 25 57.036 703.926 6. 150 3.082 3.253 5. Energy Source Asphalt Aviation Gasoline Butane Butane/Propane (60/40) Crude Oil Distillate Fuel Oil Ethane Ethane/Propane (70/30) Energy Content 6. Inc.048 4.825 3.974 5.836 ©2007 IMPCO Technologies.670 5.636 5.Approximate Heat Content of Petroleum Products Table is in millions of BTUs per barrel (42 gallons) (High heat content).130 5.539 3.308 Energy Source Isobutane Jet Fuel (Kerosene Type) Jet Fuel (Naphtha Type) Kerosene Motor Gasoline (Conventional) Motor Gasoline (Oxygenated or Reformulated) Motor Gasoline (Fuel Ethanol) Propane Energy Content 3. 131 June.800 5. 2007 .355 5.670 5.326 4. 64” 3.92” Hg) Altitude (in feet) 100 250 500 750 1000 1250 1500 1750 2000 2100 2200 2300 2400 2500 Deduct from 29.72” Altitude (in feet) 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 4000 4500 5000 5500 Deduct from 29.68” Hg.13” 3.66” 1.24” 4.39” 1.3.93” 2.85” 1.92” Hg minus 9” Hg differential with an additional deduction of 3.29” 0.92” Hg.82” 2.62” 2. An intake manifold vacuum gauge will read approximately 20.20” 2. 132 June. the values above can be deducted directly from the gauge.20” 5.34” 3.9”). Example: The manifold depression for an engine operating at 3000 feet would be the standard 29.93” 3.03” 3.67” These values can be deducted directly when reading an intake manifold depression (vacuum) gauge at one of the given altitudes on a normally aspirated engine.51” 2.12” 1.54” 3. 2007 .12” 0.92” Hg @ sea level on an unloaded engine.92” Hg 2.44” 3.74” 4. Inc. Since the 9” Hg differential between atmospheric pressure and the intake manifold does not change with altitude. or 20.92”.24” Hg=(29.41” 2.30” 2.3.Correction Table for Altitudes (Standard Atmospheric Pressure @ Sea Level is 29.72” 5.92” Hg 0.68” Hg ©2007 IMPCO Technologies.24” = 17.57” 0.24” = 17.24” 3.