VTEC Cams Specs Comparison for Bseries EnginesPage 1 sur 30 VTEC Cams Specs Comparison for Bseries Engines by [ MichaelDelaney ] (Article ID: 51) [ Print ] [ Close ] Everyone understands that more a cam aggressive gives more power due to increased mixture filling and scavenging effect for normally aspirated engines. But a wilder cam is not always better. Too much cam overlap in turbocharged/supercharged engines also increases the chance of more fresh intake boost going into the exhaust manifold instead of going into the combustion chamber (overscavenging) or a loss of cylinder pressure or intake reversion in N/A engines . So it depends on whether you are all motor N/A or force-induced: There 's no one single law for both. So what determines the best cam for your engine package? A. Beginner's Understanding of Basic Camshaft Terms: 1. Before We Start - 2 Goals You Must Know: 1. What is the PEAK WHP you are trying to achieve? AND 2. Where Do You Want The Power Gain To Be Along the RPMs (POWERBAND LOCATION) ? HOW DO THE CAM'S SPECS (LIFT, DURATION, OVERLAP or LOBE SEPARATION ANGLE, FLANK STEEPNESS) CHANGE THE POWERBAND OR TORQUE CURVE? Before you start selecting cams, you may want to first decide where you want your powerband to be. Do you want to gain power in the upper rpm range ( ie. from 5500 to 7200 rpm in a B18A/B and from 6000-8100 rpm in a B18C) or do you want the gain to be more in the midrange from 3500-6000 rpm? Remember that low rod ratio engines, like in our stock Integras, already make more power in the low to mid rpms compared to the higher rpms simply determined by the engine's piston geometry. This section is based on some lectures from Crane Cams and can help clear up some ideas about selecting cam specs for your engine package. Do you want more duration? Do you want more lift? Do you want a smaller LSA (more overlap)? How much of each? and Why? -------------------------------------------------------------------- http://www.team-integra.net/sections/articles/showArticlePrint.asp?ArticleID=51 19/11/2006 VTEC Cams Specs Comparison for Bseries Engines Page 2 sur 30 Legend for Figures Below: The red lines are comparing hp vs rpm. The green lines are comparing torque vs rpm. -------------------------------------------------------------------2. Increase Cam Duration (i.e. How Long the Valve is Open): Moves or shifts the peak torque and peak hp location to a higher rpm. The absolute peak torque and peak hp number also increases. Cam duration comparison: the aftermarket cam with 20 degrees more duration has lines with no dots. Lift and LSA are identical. Twenty degrees more duration moves the torque peak up in the rpm range by 1000 rpm (i.e. peak torque occurs later) . With 20 degrees less duration, both peak horsepower and peak torque drop. 3. Increase Cam Lift (i.e. How Much the Valve Lifts Off or Opens From Its Seat.): Higher lift gives a higher absolute peak torque and peak hp number. http://www.team-integra.net/sections/articles/showArticlePrint.asp?ArticleID=51 19/11/2006 VTEC Cams Specs Comparison for Bseries Engines Page 3 sur 30 Cam lift comparison: the cam with 0.200" (5 mm) more lift has lines with no dots. The duration and LSA are identical. Notice how the torque starts out equal at lower rpm, but the overall torque and horsepower are hurt by less lift, a sure sign of an engine that isn't getting enough mixture at higher rpm. The ideal amount of lift for the desired powerband location is also affected by the size of the intake/IM runner, size and number of the intake valves, and the amount the intake valves are "deshrouded" from the combustion chamber's wall. Lift can be further increased proportionally by changing the rocker arm ratio without having to change the cam's lift spec. 4. Tighten Lobe Separation Angle (Increase Cam Overlap): Gives more peak hp but less low end torque. 4 a) Lobe Separation Angle (LSA) Definition: This is the angle between the intake and exhaust camshaft lobe peaks described in camshaft degrees. This angle dictates two important events: the valve overlap around TDC and how much intake or exhaust valve closure delay there is (see Engine Package I Article for more details on LSA). Tightening the lobe separation angle (making the LSA value smaller)produces more overlap around TDC. Widening the lobe separation angle (making the LSA value bigger) results in less overlap. 4 b) Overlap Definition: The amount of time, expressed in crankshaft degrees, that describes the http://www.team-integra.net/sections/articles/showArticlePrint.asp?ArticleID=51 19/11/2006 team-integra. but only if the exhaust system is properly designed and sized to scavenge the cylinder.htm) : http://www. 5.VTEC Cams Specs Comparison for Bseries Engines Page 4 sur 30 window of time between the the Intake Cam's opening point BTDC and the Exhaust Cam's closing point ATDC (i. Increasing the overlap can increase peak power. LSA can also be slightly increased or decreased by changing the aftermarket adjustable cam gears settings. the brief time when both intake & exhaust valves are partially open simultaneously).Increasing the Duration of the Cam (without changing the LSA) . The smaller LSA cam produces more peak horsepower but with a loss of low-end torque. Overlap can be increased in 2 ways independently: .com/speedcrafter/Tech/camshaft/3. Tailoring the Cam Specs for the Powerband Location You Want: Changing the Duration Spec and LSA's (from www.net/sections/articles/showArticlePrint.Reducing or Tightening the LSA (without changing the Duration) Affects of Changing LSA: Compare the cam with a bigger 116 degrees lobe separation (lines with no dots) with one having a 106-degree separation (with dots).e. due to an increase in valve overlap. Decreasing the overlap tends to improve lower rpm range performance. when you dyno tune. Smaller or tighter LSA is better for a drag engine than a street machine.newcovenant.asp?ArticleID=51 19/11/2006 . Increasing the degrees of overlap tends to move the powerband up the RPM range. Moderate duration with wide separation angle might be best suited for an allaround street performance engine.asp?ArticleID=51 19/11/2006 . duration. AUC combines the effects of lift. with a high-end. and ramp. producing a strong. there's always a compromise made when you select your cam specs in N/A engines. This what makes some http://www. Here's 2 cams (red line and dotted line) with the exact same lift & duration.Long duration with a short separation angle might be suited for high-rpm drag racing.VTEC Cams Specs Comparison for Bseries Engines Page 5 sur 30 . producing a longer. Why Duration and Lift Doesn't Tell Everything About the Cam's Performance Potential ? Lift & duration don't tell the whole picture. smoother torque band that can still breathe well at higher RPM.team-integra.Short duration with a wide lobe separation angle might be best for towing. sharp torque peak. . Remember.net/sections/articles/showArticlePrint. This is the effect of cam ramp angle that can be measured with a cam doctor (blue shaded in area): it's the area under the valve lift curve (AUC) that's the major factor overall. 6. . smooth low-end torque curve. You gain hp/torque at one end of the rpms but lose it at the oppsite end. when you simply must have that extra level of performance. short duration. The forced-induced Integras like high lift. due to the B16A's differences in cylinder filling characteristics compared to the Integras which is associated with the B16A's higher rod ratio. When Do I Want To Switch To Roller Cams With Roller Rockers Instead of Standard Honda Cams and Rockers?: Consider using a Roller Cam and Roller Rockers. Toda valvesprings 50 lb.. Anytime you upgrade cams you should do 4 things: 1. But you know what valve float is right? The spring has fatigued at high rpm and loses it's ability to http://www. B. max. . if you don't upgrade the valvesprings.. big overlap (tight LSA) cams. the B16A VTEC Civics like high lift.. . The intake valve slams open faster to give a better AUC than a longer duration/lift cam and doesn't sacrifice ABDC and the need for static CR changes to compensate for the reversion loss. short overlap cams.. acceptable range is 70-90 lb.66 mm installed valvespring height) causing wear. even though the company says it's ok to use the stock ones. short duration. especially with higher redlines > 9. change to the valvesprings that were proven not to coil bind at the cam's max.net/sections/articles/showArticlePrint. The N/A Integras like high lift. 7.when competition requires valve opening and closing velocities faster than a standard rocker can provide.asp?ArticleID=51 19/11/2006 . long duration. . at 33. you still will see mild valve float.500 rpms. Mild valve float is not catastrophic compared to severe valve float or coil binding. lift on a Spintron test but not go overly stiff to create excessively high valve seat pressures (stock 40 lb.VTEC Cams Specs Comparison for Bseries Engines Page 6 sur 30 cams with lower specs perform better..when engine stress levels are high. but can't sacrifice emissions or low-end drivability. short overlap (wide LSA) cams. In contrast..team-integra. 325 in. valvespring retainer. Other Standardized Valve Lift Points to Read Duration Spec from: 2. If you can.net/sections/articles/showArticlePrint.VTEC Cams Specs Comparison for Bseries Engines Page 7 sur 30 control the rate at which the valve closes against the seat. It is easier to read the dial indicator and cam degree wheel (when you degree your cams) at 0.030 in.66 mm) and check that the lost motion devices (for VTEC cams) are all present. 0.. Domestic V8 cam manufacturers reported their cam duration @ 0. The valveface slams shut against the seat and transfers this shock or load up the valve stem to the rocker arm and then to the camshaft lobe-rocker arm interface. or 0. valveface.015 in. or Jun Type 3. if the mileage (every 4060. Ensure that the valve lash was set to the camshaft manufacturer's specs.015-0. rocker arm lobe. Ensure the install is at TDC throughout including the timing belt install.team-integra. or 33. Killer. whatever the cam manufacturer wants to quote for duration at the lowest readable valve lift on the camshaft degree wheel when they degree the cams on install). have the cams degreed. C. So the engineers chose the lowest valve lift point to take a cam reading that was also the easiest to read.D. use assembly lube on the cams during install and do the proper oil change maintenance schedule.asp?ArticleID=51 19/11/2006 . "Advertised duration" is the duration @ 0. You get extra wear-related damage and possibly structural fatigue at the valve seat.C. The Society of Automotive Engineers (SAE) chose this as their standard reference for when to measure duration .e. Use a new timing belt or a stronger aftermarket belt. http://www. the cam gears & cam journals were oriented and torqued down correctly using Honda's or the manufacturer's specs.030 in. ensure that valvespring installed height is stock (1.. and cam lobe. valve lift (i. 3. 4.320-1. or race engine) warrants it.050 in. What's with the different Duration Specs?: 1. Valve float can be identified on a chassis dynosheet as a sudden very sharp or steep drop in hp (in the order of 5% [7-10 whp] or more) at the last 500-600 rpm before the redline. and the timing belt is tensioned correctly (no flapping).020 in. 2. than at the very start of when the valve starts to lift.000 miles) or camshaft/application (Toda Spec B.5333. The smaller the number the steeper the ramp and therefore a more aggressive cam that snaps the valve open faster and closes it faster off the flank of the cam lobe.) from the cam's duration @ 0. Advanced Camshaft Tech Terms: These terms deal more with the rate at which the camshaft accelerates your valve opening and closing. Compare using the same standard quoted lift. The lower the number the faster the valve slams onto the seat. To compare between different cam manufacturers' profiles. advertised duration sounds the best for marketing hype because it is the largest duration number of the 3 standards.team-integra.05 in.: 1. It is an indication of the steepness of the ramp indirectly. Camshaft Major Intensity .05 in. you have to assume that it is "advertised duration" and not. Japanese cam manufacturers report their cam duration @ 0. So there are 3 standards from which any person can list their duration specs.04 in. Manufacturers rarely will divulge these aspects of camshaft ramp speed unless you ask them when comparison shopping.net/sections/articles/showArticlePrint. howver.make sure they are using the same lift reference point for the duration spec. Obviously. This has been their standard. valvelift duration. or 0. Bottomline: Be careful when you read and compare duration specs between 2 different cam makers.04 in. 3. (or @1mm).050 in.. Some Rarely Known ..asp?ArticleID=51 19/11/2006 . The lower the lift from which the duration is taken. The http://www. you must find the duration spec @ the same lift. A "300 degree duration" may not automatically it is bigger than a cam quoted as 270 duration @ 0. Remember this fact and don't get fooled by a sales pitch quoting no reference lift. A number that is too low can mean an excessively steep ramp and can be harmful to the valve seat itself. If there is no reference lift for the duration spec. lift quote for duration to compare apples to apples between them. make sure you use the or 0. When you shop between cams from different brands.VTEC Cams Specs Comparison for Bseries Engines Page 8 sur 30 valve lift. D.020 in.is defined as the difference between the camshaft advertised duration (valve lift @ 0. the bigger the number for duration. It is an estimate of the cam's ramp. if adjustments are needed. coil binding height.camshaft makers can grind you a custom lobe spec but require you to provide them with the bore.asp?ArticleID=51 19/11/2006 . Now let's get on with the spec comparisons between VTEC cams for the Integra. rod length. powerband location (rpm range where you want your peak torque to reside). The thicker the shim. injector size. it can be done by shimming the valves to equalize pressures. Custom Camshafts . pay close attention to the installed height. This ensures that the springs have the required pressure to keep the valves shut. Height is checked by measuring the distance between the spring seat in the head and the retainer on the valve stem.e. RPM Bounce. the more it increases spring pressure. and port flow capacity numbers (not just peak flow but also your flow rates at various valve lifts). though. Don't overshim.. static CR.is the speed beyond which the valvetrain can't be turned any faster. seat opening & closing pressures. come in various thicknesses and are usually serrated on one side to prevent rotation (the serrated side faces the head).net/sections/articles/showArticlePrint. Valvespring Install Considerations and Checks Please read this link to familiarize yourself with the terms used to select the proper valvespring for your cams (i. retainer to oil seal clearance. rocker to retainer clearance): http://cranecams. 3..This maximum should be much higher than your redline. because doing so may lead to coil bind with a high-lift cam http://www. E. Most performance valve springs are closely matched but. installed height.team-integra. This spec should be much higher than your redline. retainer to guide clearance. 4. Shims are made of hardened steel.each camshaft spec will induce significant valve face bounce off the valve seat at a certain rpm.com/?show=faq&id=5 From Larry Carley's Informative Articles: " When installing performance valve springs. Camshaft Limit Speed . stroke.VTEC Cams Specs Comparison for Bseries Engines Page 9 sur 30 accepted number for major intensity is one that is > 32 degrees. 2. about 8-10 peak whp gain properly tuned.com/question562. Proper Cam Break-In Procedure : 2000 rpm . 20 min." F. If the engine does not fire up on the first couple of cranks.htm The initial higher rpms (eg.co. The spacing between the spring coils must also be checked with the valves at full lift to make sure the springs do not bind.net/spfeature/vtecimpl/vtec1. . do not continue to try to turn it over with multiple attempts as this will cause extreme wear and scoring on your new cams.pumaracing. please read these good links first before starting here: http://www.asp?ArticleID=51 19/11/2006 . : The 2000-2001 ITR cams are identical to CTR cams. duration.howstuffworks.net/sections/articles/showArticlePrint. I. A minimum clearance of . For beginners who aren't familiar with what cam lift. http://www. This can be done by inserting a feeler gauge between the coils. The exhaust cams for both are identical.com/camshaft.060 inch is usually recommended. Mild Cam Upgrade: ITR cams CTR cams differ only with the 1997-1999 ITR cams at the intake VTEC lobe duration ( by only 3 degrees more duration ) and ramp angle. High lift cams and/or rocker arms push the valves open more. so it's important to make sure there's still some room between the coils at maximum lift. And yet the 2000-2001 ITR's make identical power to 1997-1999 ITR's!! There's no advantage in getting CTR cams for a B18C. and VTEC are.howstuffworks.VTEC Cams Specs Comparison for Bseries Engines Page 10 sur 30 or rocker arms.vtec. 2000 rpm for 20-30 min) that is varied up and down is done to minimize wear on the nose of the cam lobe at first usage and to circulate more oil to the rockers/cam lobe.that's it!! The intake max.uk/cam1.htm http://asia. http://www. lift are identical. Locate the cause of the non-start up problem instead immediately.. (lather cams with molybdenum based assembly lube on install).team-integra.htm http://www.html II. 5 in. and Zex 57300.VTEC Cams Specs Comparison for Bseries Engines Page 11 sur 30 III. Crower 63402/403 cams.asp?ArticleID=51 19/11/2006 . Zex 57200. Toda Spec A.team-integra. about 22-25+ whp gain. IV. http://www. Crower 63412 or 63413. and ECU reprogramming. Needs valvesprings upgraded. collector header. VI. JDM style long primaries with 2. if properly combined in a package and tuned. Skunk2 Stage 1. Do not need compression increase but an increase will help gain more from the cams. compression increase . Cam Specs: The Honda cam has 3 lobes per cylinder: The two staggered primary non-VTEC lobes flank the middle bigger VTEC lobe. Skunk2 Stage 2 or Stage 3. Hytech sells their own line of roller race cams as well but chose not to divulge their specs to me.Use JDM style 2. about 15-20 whp properly tuned. V. collector header. Moderate Cam Upgrade: Spoon. Jun Type 3. Crane Standard Follower.5 in. Very interesting but unknown performance wise: Crane and Ferrea partnered to make Crane Roller Follower cam 253-0514 with Crane Roller Rockers 253-0805 (also known as RR1000 Roller Rockers) which are made by Ferrea .net/sections/articles/showArticlePrint. Aggressive/Extreme Cams: Toda Spec B/C. the center cam and rocker are turning and moving. The switchover between the primary and secondary cam operations is variable. The other 5-mm lift primary cam-valve combination follows 10 (degrees) later. load. flanking the lone "secondary" or highspeed cam. At higher rpm and higher (engine) load conditions.net/sections/articles/showArticlePrint. For example.team-integra. Interconnection of the three rocker arms is controlled by an ECU that gathers signals on engine rpm. and other relevant data. but are disengaged from operating the valves. Obviously the secondary power cams have a wider opening period and a higher lift: a 90 (degree) overlap and a 10-mm lift. further filling the combustion chamber. water temperature. The primary valves have milder timings and smaller lifts. the latter 8 mm and 5 mm.asp?ArticleID=51 19/11/2006 . the 8-mm lift one. vehicle speed. which are now operated by the center power cam that opens the valves longer and lifts them higher for producing more power. One of these primary cams.VTEC Cams Specs Comparison for Bseries Engines Page 12 sur 30 quote: by Jack Yamaguchi at Automotive Engineering on the first street VTEC cam on a JDM b16A in 1988 (Moderator's note: When Jack speaks of cams in this quote. dependent on load and rpm. with intake http://www.which is indeed similar to those of a Group A racing Civic. While the primary cams are opening and closing the valves. The cams have different profiles and lift amounts. On either side are "primary" or low-to-mid-speed cams. letting mixtures in and generating swirl motion. he is referring to the individual cam lobes on a VTEC cam.) There are three cams and three rockers per pair of valves. a hydraulically operated piston pushes in a two-piece pin interconnecting the three rocker arms in unison. operates its intake valve first via rocker arm. 50 for the nonVTEC lobes. and JG.10. All profiles listed here represent the VTEC lobe spec only and duration is @1mm or 0. Marketing is huge and only an uninformed customer does not understand that reporting the domestic duration standard @ 0. All recommend stock Honda specs for the valvespring installed height. RS Machine (Exospeed) will not release the specs for their race or street cams when we asked . do NOT list the standard 1mm or 0. Gude.net/sections/articles/showArticlePrint. with -100 mmHg at 5000. except for Jun.020 in.227@1mm 1. Web Camshafts makes very good quality hard weld cams ground to any spec you request.duration .05 in. Anything below. the secondary power cam comes on at 4800 rpm. lift is not providing fair comparative profile info between import cam grinds . All of the aftermarket cams listed below are billet core. valve lift spec for duration.55 for the VTEC lobe and 1. duration .asp?ArticleID=51 19/11/2006 .0394 in. except Skunk2.team-integra. lift or advertised duration @ 0. ITR/CTR (Chilled Cast Cores) http://www. Valve lash settings can be obtained from the manufacturer. unless otherwise specified (manufacturer was unwilling to provide the spec). valve lift (which is the import standard for comparing cam profile durations).0394 in.4mm.VTEC Cams Specs Comparison for Bseries Engines Page 13 sur 30 manifold vacuum of -20 mmHg. STOCK GSR : b17a and b18c1 (Chilled Cast Core) INTAKE lift . the primary low and mid-range cams produce ample torque and tractable power. and optimum -300 mmHg load at 5200 rpm. All rocker arm ratios are stock at 1. non-reground cams. Notice that ALL manufacturer's websites. No ramp/flank angles or ramp speeds are provided. Prices listed are from the manufacturer's link (MSRP) in US dollars.9. unless otherwise stated.6 mm.015-0. I don't cover the specs of regrind VTEC cams available like Web.230 @1mm EXHAUST lift . 10.com .hybridgarage. duration 235 @1mm AFTERMARKET CAMS (LISTED IN ALPHABETICAL ORDER) 2. http://www.5mm. Chill Cast Cores ) http://www.STOCK CTR and 2000-2001 ITR (CTR intake cam $300-350) INTAKE lift .wicked-industries.VTEC Cams Specs Comparison for Bseries Engines Page 14 sur 30 http://tech. duration 243 @1mm EXHAUST lift . Tuner Series($450-535 US / pr) INTAKE lift .11.11.team-integra.10.5 mm. duration 235 @1mm . duration 240 @1mm EXHAUST lift .11.Type A .5 mm. Blox (no @1mm specs available) ( MSRP $750 US/pr for Tuner Series not Competition Series. ITR intake cam $250-290) INTAKE lift .com/tech/bseries.asp?ArticleID=51 19/11/2006 .com website and the legend of b16a section which is now 404) .7 mm.5mm.STOCK 1997-1999 ITR ($500-580/pr.html (originally this table came from Frank Lin's old gspeed.05 in.net/sections/articles/showArticlePrint. duration 247 @ 0. asp?ArticleID=51 19/11/2006 .net/sections/articles/showArticlePrint.6 mm.12. duration 239 @0. EXHAUST lift . duration 255 @0. .12.5 mm.7mm. duration 250 @1mm EXHAUST lift . duration 256 @0.Type B. Competition Series ($510-570 US /pr) INTAKE lift .05 in. duration 266 @0.2 mm.05 in. duration 269 @1mm EXHAUST lift .Type HSL. duration 266 @0. 10124 Race. .8 mm. Competition Series Type B . or Turbo yet.11.05 in.05 in.VTEC Cams Specs Comparison for Bseries Engines Page 15 sur 30 EXHAUST lift .5mm.Spec 4 ($600 US /pr) INTAKE lift . 3.team-integra.10.12.Spec 3 Plus ($549 US / pr) INTAKE lift .11.05 in. no available specs for Tuner Series Type HSL or Turbo. duration 245 @1mm .3 mm.12.12.4 mm. Tuner Series ($450-540 US /pr) INTAKE lift . duration 274 @1mm http://www. Buddy Club .0 mm.11. EXHAUST lift . duration 248 @ 0.Stage 1 (part no. http://www.jrponline.11. duration 243 @ 1mm EXHAUST lift .com/ INTAKE lift .team-integra.$773. despite the relatively mild specs on the VTEC lobe.1 mm. http://www.05 in. Crane Standard Tappet & Race Only Roller Follower Cams The specs listed on the Crane Cams website are at 0.99 mm. duration 237 @ 1mm .11. Cat from Europe ($485 US / pr) These 2501606 billet VTEC road racing cams come from the Euporean import scene and Cat are cam makers for some of the Honda British Touring Car Championship teams.10.8mm.33/pr) INTAKE lift.com/import/avteccams. duration 240 @1mm 5.10.asp?ArticleID=51 19/11/2006 . They require a VTEC/fuel controller like the Apex VAFC for tuning the idle and have an aggressive ramp and more aggressive nonVTEC lobes. 2530010 . 2530012) INTAKE lift.htm . valve lift.Stage 2 (part no. Thanks to Dave Maxwell at Crane for forwarding the duration @1mm valve lift specs for the Stage 1 cams.05 in.32mm. http://www.11. duration 242 @1mm EXHAUST lift . Thanks goes to Steve at Johnston Research & Performance for the info.cranecams.net/sections/articles/showArticlePrint.6 mm.VTEC Cams Specs Comparison for Bseries Engines Page 16 sur 30 4. 05 in.com/Import_Cars_/import_cars_..ferrea.12. EXHAUST lift . 2530514 $629/pr but must also purchase Crane/Ferrea Roller Followers Set price . you'll notice that there's an "arc" or radius to the rocker pad's configuration.unknown.5" or so.html Crane/Ferrea Roller Followers Should Not Be Used With Standard Follower Cams (Here's Why): quote: Larry Widmer at Endyn All cams designed to work with Honda rocker arms utilize almost the full length of the rocker pad.39 mm.99 mm. . duration 248 @ 0.11. so imagine the diameter of the circle it would be part of..VTEC Cams Specs Comparison for Bseries Engines Page 17 sur 30 EXHAUST lift . duration 254 @ 0.6 mm. but the circle would be quite large .05 in. This radius is quite large.team-integra.05 in. I haven't measured it. 2530016) INTAKE lift. In order to have the same valve action (as with the Honda rockers) from a Honda "type" camshaft.something on the order of 2. duration 242 @0. Since there's no http://www. If you hold a Honda rocker arm so you can look at it from the side (looking through the shaft axis).net/sections/articles/showArticlePrint. were it extended.11.asp?ArticleID=51 19/11/2006 . See comments below about using roller cams and standard rockers or followers) http://www.Stage 3 (part no. the radius of the roller in the rocker arm would have to be that same (large) diameter.Crane/Ferrea Roller Cams (part no. . This causes the effective rocker arm ratio to vary as the cam acts across the span of the pad. 6. not to mention that the mass would be "extreme".team-integra. duration 238 @1mm .asp?ArticleID=51 19/11/2006 .98 mm. This means that anytime you use the roller rocker on a cam ground for Honda rockers.63403 INTAKE lift .11. Bottom line is that you will not make as much power with these roller rockers. as you would with the Honda rockers. so that's why we adopted that number as our advertised number. .net/sections/articles/showArticlePrint. duration 228 @1mm .VTEC Cams Specs Comparison for Bseries Engines Page 18 sur 30 room for a roller that's that large.11.63412 N/A Race Core Cams http://www. Crower VTEC Cams (Chilled Cast Cores) http://www.11.83 mm.According to Brian the reason why he did not provide the duration @ 1mm: "The Toda advertised specs are at . any roller rocker arm that has a roller that's smaller can not provide the same valve action.11.0143".crower.63402's have the same lift but lopier idle and bigger intake duration than the 63402A : INTAKE lift .83 mm. duration 237 @1mm EXHAUST lift .com/ Here are the cam durations @ 1mm valve lift which are not on the Crower website. duration 246 @1mm EXHAUST lift ." All cams $642/pr.81 mm. you won't achieve as much area under the valve lift curve and the opening / closing rates will also be slowed considerably. Thanks to Brian Crower for providing these. 63413 N/A Race Core Cams INTAKE lift . Jun http://www.05 in.duration .(estimated) 260 @1 mm EXHAUST lift .VTEC Cams Specs Comparison for Bseries Engines Page 19 sur 30 INTAKE lift .07 mm.81 mm.(estimated) 242 @1 mm EXHAUST lift .duration .(estimated) 258 @1 mm .(estimated) 238 @1 mm 7.12.team-integra.11. The intake ABDC closing spec is 52 degrees. 307 Cam (Race Only. 8.asp?ArticleID=51 19/11/2006 .net/sections/articles/showArticlePrint.(estimated) 269 @1 mm EXHAUST lift .11.11. EXHAUST lift .84 mm. duration .11.07 mm.63411T Turbo Race Core Cams INTAKE lift .(estimated) 252 @1 mm . duration .11. $649/pr) INTAKE lift . duration 248 @0.dprracing.com/pages/products/cams.99 mm. duration 248 @0.05 in.duration .htm Dan Paramore did not get back to me to provide the duration @1mm lift specs when I had requested them.11.81 mm.12.84 mm.30 mm. Dan Paramore http://www. duration . duration 265 @ 1mm (Advertised 304) EXHAUST lift . lift and duration 1mm valve lift specs for the VTEC lobes : . duration 265 @ 1mm (Advertised 304) EXHAUST lift . use oversized stainless valves.5 mm.Type 1 INTAKE lift .html?en#B16A/B16B/B18C Here are their max.10.12.Type 3 ($890/pr) INTAKE lift .0 mm.9 mm.5 mm. advanced cam gear timing more than 3 degrees. duration 265 @ 1mm (Advertised 304) Jun Type 3's have the reputation of eating valves if you milled the head. duration 265 @ 1mm EXHAUST lift .0 mm.12.Type 4($??/pr) INTAKE lift .junauto.12.5 mm. duration 265 @ 1mm (Advertised 304) .VTEC Cams Specs Comparison for Bseries Engines Page 20 sur 30 Here is Jun's website: http://www.12.asp?ArticleID=51 19/11/2006 .11.co. duration 268 @ 1mm .10. duration 267 @ 1mm EXHAUST lift .team-integra.net/sections/articles/showArticlePrint.9 mm.10.0 mm. duration 265 @ 1mm .jp/products/cylinderhead-part/camshaft/highcamshaft-honda. http://www.Type 2 INTAKE lift . or use non-Jun or non-Toda valvesprings. BP285 INTAKE lift .co.asp?ArticleID=51 19/11/2006 . http://www. duration 256 @ 1mm EXHAUST lift .11.12.uk .6 lift 274 advertised duration) not listed since we don't have their @1mm duration specs but are much less aggressive than M22's.team-integra.net/sections/articles/showArticlePrint. duration 256 @ 1mm 10. M22 (street N/A) INTAKE lift .12. formerly EF-1) thanks goes to Tom (aka Tbone) for emailing me the @1mm duration specs. Piper Here is Piper's website: http://www.1 mm.com/ M20 and M21 specs (11.11. Rocket Motorsports (formerly Hondasaver. duration 244 @ 1mm EXHAUST lift .VTEC Cams Specs Comparison for Bseries Engines Page 21 sur 30 9.m24x. These cam lobes come Parkerized coated.1 mm. ($750/pr or $990 with RM valvesprings as a kit).6 mm.pipercams.5-11.2 mm. duration 244 @ 1mm http://www. 1 mm. duration 263 @ 1mm M24X INTAKE lift .1 mm. duration 258 @ 1mm EXHAUST lift .12. duration 263 @ 1mm EXHAUST lift .1 mm.12.1 mm. duration 252 @ 1mm M24 plain (no longer available) INTAKE lift .7 mm.12.1 mm.1 mm.12.12.asp?ArticleID=51 19/11/2006 .12. duration 258 @ 1mm EXHAUST lift .1 mm. duration 270 @ 1mm EXHAUST lift . duration 270 @ 1mm M25E http://www.12. duration 252 @ 1mm EXHAUST lift .VTEC Cams Specs Comparison for Bseries Engines Page 22 sur 30 M23 (no longer available) INTAKE lift .net/sections/articles/showArticlePrint.team-integra. duration 265 @ 1mm M25 INTAKE lift .12. duration 258 @ 1mm M24E INTAKE lift .12.7 mm.12.7 mm. duration 252 @ 1mm EXHAUST lift . duration 276 @ 1mm MXX Propriety Specs for Contracted Race Teams. X denotes 1 large nonVTEC lobe resulting in staggering like the stock nonVTEC lobes layout for swirl filling and good emissions/idle quality.13.Pro I+ for B series INTAKE lift.11.10. duration 266 @ 1mm http://www.net/sections/articles/showArticlePrint.12.58 mm.8 mm. 11.6 mm.50/pr. duration 276 @ 1mm EXHAUST lift . duration 264 @ 1mm EXHAUST lift .asp?ArticleID=51 19/11/2006 . retail $849/pr) INTAKE lift.25 mm.11.skunk2. Here are the specs provided by Dave Hsu at Skunk2 to me: . $700-725/pr. At the time of writing this article. CARB Exempt pending) INTAKE lift.12. duration 249 @1mm .team-integra. retail $797/pr.13.3 mm.Stage II (Not CARB Exempt.com now have the specs available. duration 264 @ 1mm .Stage I (best price $712.VTEC Cams Specs Comparison for Bseries Engines Page 23 sur 30 INTAKE lift . XX denotes 2 large nonVTEC lobes unstaggered like the Toda cams' nonVTEC lobes.25 mm.com. Skunk2 (Chilled Cast Cores) www.9 mm. they did not have the specs listed and I had emailed them via info@skunk2. With the current (Stage I) cam our goal was to make as much power using stock valvetrain. Spoon ($1045/pr) http://www.com : These (Stage I) cams pass smog and do not require the use of new valvesprings (though recommended). $700-725/pr.12.8 mm. B18C1 engine makes 17+ more to the tire on average. 12. We have only seen 2-4hp increases when using toda B's or jun3's. while preserving driveability.Stage III . duration 270 @ 1mm EXHAUST lift .11.(race only. Please inform your readers that bigger is not necessarily better. reliability.net/sections/articles/showArticlePrint.VTEC Cams Specs Comparison for Bseries Engines Page 24 sur 30 EXHAUST lift .asp?ArticleID=51 19/11/2006 . Neither pass smog. duration 279 @ 1mm quote: I had an interesting discussion with Dave Hsu at skunk2. retail $849/pr) INTAKE lift.8 mm. duration 262 @ 1mm . Both require new valve train and in the case of Jun's.team-integra. there is only a 3-4 degree margin of error before the valves grab each other and destroy the motor. and emission friendliness.11.8 mm. Toda The advertised duration @ 0.12mm.12.11.Spec C's ($1100/pr) INTAKE lift . duration 255 @1mm EXHAUST lift . duration 255 @1mm EXHAUST lift .6 mm.2mm.13 mm. duration 245 @1mm .53 mm.12.015 in.Spec B's ($980/pr) INTAKE lift .com/products/honda_b16a_b18c/camshafts.todaracing.12 mm.11. duration 256 @1mm EXHAUST lift .11.html .5mm.5 mm. lift can be found on their website.VTEC Cams Specs Comparison for Bseries Engines Page 25 sur 30 Specs were kindly provided by Alan Chow at A&J Racing http://www.duration 250 @1mm EXHAUST lift .Spec A's ($920/pr) INTAKE lift .spoon-sports. Thanks to Ali Jahed at AKH Racing for the duration @1mm valve lift specs. duration 245 @1mm 13.11.asp?ArticleID=51 19/11/2006 .net/sections/articles/showArticlePrint.team-integra. duration 240 @1mm .com/ INTAKE lift .: http://www. duration 255 @1mm http://www. If you (have) to run cams like those.. This tool fits in a collet on the Serdi machine and it not only machines the top of the guide.12.team-integra. We also have a tool that we've built that allows us to machine the tops of the valve guides down in height to get some much-needed clearance between the bottom of the spring retainer and the top of the valve seal.11. valvetrain separation occurs and the valves typically end up being "dropped" on the seats.net/sections/articles/showArticlePrint.Spec D's ($ Not Available/pr.VTEC Cams Specs Comparison for Bseries Engines Page 26 sur 30 . thus pounding out the valves and seats. You MUST run a spring that has at least 1. Toda valvesprings are required. duration . you can't run springs that "fit" in an installed height that's relatively "stock".If you rev past 8400 rpm.9 mm.asp?ArticleID=51 19/11/2006 .at least with Todas. Toda D's have the highest non-roller intake lift in the market. The potential damage from weakened valve springs is that great in my opinion.400" installed height with about 68-70 psi on the seat.estimated 265 @1mm (Advertised 305) EXHAUST lift .estimated 275 @1mm (Advertised 315) In terms of streetable cams. duration . but it also machines the http://www. RACE ONLY ) INTAKE lift . When the springs go soft.. rather than eased to their seats by the closing ramps on the cams. I also don't think their valve springs are up to the task either. I won't build any engine with Toda cams these days because there are no springs we've ever found that will last any length of time with them.9 mm. quote: Interesting Comments by Endyn on Toda B-D Cams: Valve problems can also be attributed to valve springs failing to control valve motion. 5 mm.VTEC Cams Specs Comparison for Bseries Engines Page 27 sur 30 sides and step so the seal will actually sit lower.team-integra. oil is forced (by the retainer) through the guide.asp?ArticleID=51 19/11/2006 . duration 255 @1mm http://www.060" clearance between the retainer and the seal. On heads running in engines with cams with . contaminating the mixture. duration 265 @1mm EXHAUST lift .com/products/honda_b16a_b18c/vtec_killer.11.485" or higher lift. and burning oil.net/sections/articles/showArticlePrint.0 mm.todaracing. .Race-Only "Killer Cams" ($1.12. If you don't.html INTAKE lift .800/pr includes solenoid oil line plug) http://www. we always machine the top of the guides to maintain . To go beyond 10k rpm one better have some strong yet light weight piston/rods.000 rpm. They have JUST 2 NON-VTEC BIG ASS SIZED LOBES FROM THE START. The biggest difference is the much reduced valve train weight.. idles at 2000 rpm. There is NO STAGGERED LIFT/DURATION for enhanced low rpm swirl filling as seen in the stock nonVTEC primary lobes. according to Ali Jahed at AKH Racing (Toda official distributor in North America) : quote: The duration isn't much more than the Spec C's.VTEC Cams Specs Comparison for Bseries Engines Page 28 sur 30 quote: The profile is similar to spec C's. you should be aware that the duration at 1mm valve lift is only 265 degrees which is identical to the Toda Spec C. redline at 12. and have a powerband from 5000-12000 rpm. http://www. For full race you don't need VTEC components. So what's so special about them? Well.. They just weigh you down. When you look at the 305 degrees "advertised duration" spec for the Toda Killer cam. These race-only cams are light as hell. There is NO VTEC LOBE. but the ramp speed/angle is waaaay different.net/sections/articles/showArticlePrint.asp?ArticleID=51 19/11/2006 .team-integra. 14.zex. Lift and duration specs are not the only numbers to look at.net/sections/articles/showArticlePrint.VTEC Cams Specs Comparison for Bseries Engines Page 29 sur 30 As you already know.team-integra.asp?ArticleID=51 19/11/2006 . Zex/Comp Cams http://www. lift/duration don't tell the whole story when it comes to camshafts and in this case the lower inertia (hollow core) and consistent oil pressure (no vtec solenoid) contribute to consistent performance and improved throttle response which is top priority in a professional race car.com http://www. Clearance ramp and flank angles or the steepness of how fast the valves open and close also is important to performance. 12. .11. no valvespring change required: INTAKE lift .57200. high compression and major port work needed. duration 230 @ 0.57100.05 in.com/catalog/192_193.20 mm.13.net/sections/articles/showArticlePrint.05 in.team-integra. EXHAUST lift .05 in.90 mm. All $566.11.43 mm.61/pr (the 57300 are by far the best bargain on the market).000 rpm engines only: INTAKE lift . Posted 2/16/2002 6:44:18 PM http://www.11. duration 248 @ 0. duration 228 @ 0. duration 258 @ 0.compcams. EXHAUST lift .asp?ArticleID=51 19/11/2006 . for racing only.9.VTEC Cams Specs Comparison for Bseries Engines Page 30 sur 30 or http://www.57300. EXHAUST lift .05 in.05 in. .45 mm.html Thanks to Matt Patrick at Zex (Comp Cams). for 10. valve spring change is required: INTAKE lift .05 in. duration 260 @ 0. duration 246 @ 0.05 mm.94 mm. .
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