VTEC Cams Specs Comparison for Bseries Engines - Team Integra Forums - Team Integra
Rating: 35 votes, 4.43 average.

VTEC Cams Specs Comparison for Bseries Engines

Posted 02-16-2002 at 12:00 AM by MichaelDelaney

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?


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.

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 window of time between the the Intake Cam's opening point BTDC and the Exhaust Cam's closing point ATDC (i.e. the brief time when both intake & exhaust valves are partially open simultaneously).
Increasing the degrees of overlap tends to move the powerband up the RPM range. Increasing the overlap can increase peak power, but only if the exhaust system is properly designed and sized to scavenge the cylinder. Decreasing the overlap tends to improve lower rpm range performance.
Overlap can be increased in 2 ways independently:
- Increasing the Duration of the Cam (without changing the LSA) - 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). The smaller LSA cam produces more peak horsepower but with a loss of low-end torque. Smaller or tighter LSA is better for a drag engine than a street machine, due to an increase in valve overlap. LSA can also be slightly increased or decreased by changing the aftermarket adjustable cam gears settings, when you dyno tune.

5. Tailoring the Cam Specs for the Powerband Location You Want: Changing the Duration Spec and LSA's (from http://www.newcovenant.com/speedcraf...camshaft/3.htm) :

- Short duration with a wide lobe separation angle might be best for towing, producing a strong, smooth low-end torque curve.

- Long duration with a short separation angle might be suited for high-rpm drag racing, with a high-end, sharp torque peak.

- Moderate duration with wide separation angle might be best suited for an all-around street performance engine, producing a longer, smoother torque band that can still breathe well at higher RPM.

Remember, there's always a compromise made when you select your cam specs in N/A engines. You gain hp/torque at one end of the rpms but lose it at the oppsite end.

6. Why Duration and Lift Doesn't Tell Everything About the Cam's Performance Potential ?

Lift & duration don't tell the whole picture. Here's 2 cams (red line and dotted line) with the exact same lift & duration. 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. AUC combines the effects of lift, duration, and ramp. This what makes some cams with lower specs perform better. 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.

7. 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.....

- when engine stress levels are high.

- when competition requires valve opening and closing velocities faster than a standard rocker can provide, especially with higher redlines > 9,500 rpms.

- when you simply must have that extra level of performance, but can't sacrifice emissions or low-end drivability.

The N/A Integras like high lift, long duration, big overlap (tight LSA) cams. The forced-induced Integras like high lift, short duration, short overlap (wide LSA) cams. In contrast, the B16A VTEC Civics like high lift, short duration, short overlap cams, due to the B16A's differences in cylinder filling characteristics compared to the Integras which is associated with the B16A's higher rod ratio.

B. Anytime you upgrade cams you should do 4 things:

1. change to the valvesprings that were proven not to coil bind at the cam's max. lift on a Spintron test but not go overly stiff to create excessively high valve seat pressures (stock 40 lb., Toda valvesprings 50 lb., max. acceptable range is 70-90 lb. at 33.66 mm installed valvespring height) causing wear.
if you don't upgrade the valvesprings, even though the company says it's ok to use the stock ones, you still will see mild valve float. Mild valve float is not catastrophic compared to severe valve float or coil binding. But you know what valve float is right? The spring has fatigued at high rpm and loses it's ability to control the rate at which the valve closes against the seat. 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. You get extra wear-related damage and possibly structural fatigue at the valve seat, valveface, rocker arm lobe, valvespring retainer, and cam lobe. 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.
2. ensure that valvespring installed height is stock (1.320-1.325 in. or 33.53-33.66 mm) and check that the lost motion devices (for VTEC cams) are all present.
3. use assembly lube on the cams during install and do the proper oil change maintenance schedule.
4. Ensure the install is at TDC throughout including the timing belt install. Use a new timing belt or a stronger aftermarket belt, if the mileage (every 40-60,000 miles) or camshaft/application (Toda Spec B,C,D, Killer, or Jun Type 3, or race engine) warrants it. If you can, have the cams degreed. Ensure that the valve lash was set to the camshaft manufacturer's specs, the cam gears & cam journals were oriented and torqued down correctly using Honda's or the manufacturer's specs, and the timing belt is tensioned correctly (no flapping).

C. What's with the different Duration Specs?:
1. "Advertised duration" is the duration @ 0.015 in., 0.020 in., or 0.030 in. valve lift (i.e. 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).
The Society of Automotive Engineers (SAE) chose this as their standard reference for when to measure duration . It is easier to read the dial indicator and cam degree wheel (when you degree your cams) at 0.015-0.030 in. than at the very start of when the valve starts to lift. So the engineers chose the lowest valve lift point to take a cam reading that was also the easiest to read.
Other Standardized Valve Lift Points to Read Duration Spec from: 2. Domestic V8 cam manufacturers reported their cam duration @ 0.050 in. valve lift. This has been their standard.
3. Japanese cam manufacturers report their cam duration @ 0.04 in. (or @1mm).
The lower the lift from which the duration is taken, the bigger the number for duration.
So there are 3 standards from which any person can list their duration specs. To compare between different cam manufacturers' profiles, howver, you must find the duration spec @ the same lift. Obviously, advertised duration sounds the best for marketing hype because it is the largest duration number of the 3 standards. Remember this fact and don't get fooled by a sales pitch quoting no reference lift. If there is no reference lift for the duration spec, you have to assume that it is "advertised duration" and not. When you shop between cams from different brands, make sure you use the or 0.04 in. or 0.05 in. lift quote for duration to compare apples to apples between them. A "300 degree duration" may not automatically it is bigger than a cam quoted as 270 duration @ 0.05 in. Compare using the same standard quoted lift.
Bottomline: Be careful when you read and compare duration specs between 2 different cam makers...make sure they are using the same lift reference point for the duration spec.

D. Some Rarely Known , Advanced Camshaft Tech Terms:
These terms deal more with the rate at which the camshaft accelerates your valve opening and closing. Manufacturers rarely will divulge these aspects of camshaft ramp speed unless you ask them when comparison shopping.:
1. Camshaft Major Intensity - is defined as the difference between the camshaft advertised duration (valve lift @ 0.020 in.) from the cam's duration @ 0.050 in. valvelift duration. It is an estimate of the cam's ramp. 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.
It is an indication of the steepness of the ramp indirectly. A number that is too low can mean an excessively steep ramp and can be harmful to the valve seat itself. The lower the number the faster the valve slams onto the seat. The accepted number for major intensity is one that is > 32 degrees.
2. Camshaft Limit Speed - is the speed beyond which the valvetrain can't be turned any faster.This maximum should be much higher than your redline.
3. RPM Bounce- each camshaft spec will induce significant valve face bounce off the valve seat at a certain rpm. This spec should be much higher than your redline.

Now let's get on with the spec comparisons between VTEC cams for the Integra...
4. Custom Camshafts - camshaft makers can grind you a custom lobe spec but require you to provide them with the bore, stroke, rod length, static CR, injector size, powerband location (rpm range where you want your peak torque to reside), and port flow capacity numbers (not just peak flow but also your flow rates at various valve lifts). E. 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.e. installed height, seat opening & closing pressures, coil binding height, retainer to oil seal clearance, retainer to guide clearance, rocker to retainer clearance): http://cranecams.com/?show=faq&id=5 From Larry Carley's Informative Articles: " When installing performance valve springs, 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. Most performance valve springs are closely matched but, if adjustments are needed, it can be done by shimming the valves to equalize pressures. Shims are made of hardened steel, come in various thicknesses and are usually serrated on one side to prevent rotation (the serrated side faces the head). The thicker the shim, the more it increases spring pressure. Don't overshim, though, because doing so may lead to coil bind with a high-lift cam or rocker arms. The spacing between the spring coils must also be checked with the valves at full lift to make sure the springs do not bind. 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. This can be done by inserting a feeler gauge between the coils. A minimum clearance of .060 inch is usually recommended." F. Proper Cam Break-In Procedure : 2000 rpm , 20 min. (lather cams with molybdenum based assembly lube on install). http://www.pumaracing.co.uk/cam1.htm The initial higher rpms (eg. 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. If the engine does not fire up on the first couple of cranks, do not continue to try to turn it over with multiple attempts as this will cause extreme wear and scoring on your new cams. Locate the cause of the non-start up problem instead immediately. I. For beginners who aren't familiar with what cam lift, duration, and VTEC are, please read these good links first before starting here:

II. 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..that's it!! The intake max. lift are identical. The exhaust cams for both are identical. :
The 2000-2001 ITR cams are identical to CTR cams.
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. - about 8-10 peak whp gain properly tuned.

III. Moderate Cam Upgrade: Spoon, Toda Spec A, Crower 63402/403 cams, Skunk2 Stage 1, Crane Standard Follower, Zex 57200.
Do not need compression increase but an increase will help gain more from the cams.Use JDM style 2.5 in. collector header. about 15-20 whp properly tuned.

IV. Aggressive/Extreme Cams: Toda Spec B/C, Jun Type 3, Skunk2 Stage 2 or Stage 3, Crower 63412 or 63413, and Zex 57300.
Needs valvesprings upgraded, compression increase , JDM style long primaries with 2.5 in. collector header, and ECU reprogramming. about 22-25+ whp gain, if properly combined in a package and tuned.

V. 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 . Hytech sells their own line of roller race cams as well but chose not to divulge their specs to me.

VI. Cam Specs:

The Honda cam has 3 lobes per cylinder: The two staggered primary non-VTEC lobes flank the middle bigger VTEC lobe.

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, he is referring to the individual cam lobes on a VTEC cam.)

There are three cams and three rockers per pair of valves. The cams have different profiles and lift amounts. On either side are "primary" or low-to-mid-speed cams, flanking the lone "secondary" or high-speed cam. Obviously the secondary power cams have a wider opening period and a higher lift: a 90 (degree) overlap and a 10-mm lift,which is indeed similar to those of a Group A racing Civic.

The primary valves have milder timings and smaller lifts, the latter 8 mm and 5 mm. One of these primary cams, the 8-mm lift one, operates its intake valve first via rocker arm, letting mixtures in and generating swirl motion. The other 5-mm lift primary cam-valve combination follows 10 (degrees) later, further filling the combustion chamber.

While the primary cams are opening and closing the valves, the center cam and rocker are turning and moving, but are disengaged from operating the valves. At higher rpm and higher (engine) load conditions, a hydraulically operated piston pushes in a two-piece pin interconnecting the three rocker arms in unison, which are now operated by the center power cam that opens the valves longer and lifts them higher for producing more power. Interconnection of the three rocker arms is controlled by an ECU that gathers signals on engine rpm, load, vehicle speed, water temperature, and other relevant data.

The switchover between the primary and secondary cam operations is variable, dependent on load and rpm. For example, with intake manifold vacuum of -20 mmHg, the secondary power cam comes on at 4800 rpm, with -100 mmHg at 5000, and optimum -300 mmHg load at 5200 rpm. Anything below, the primary low and mid-range cams produce ample torque and tractable power. All profiles listed here represent the VTEC lobe spec only and duration is @1mm or 0.0394 in. valve lift (which is the import standard for comparing cam profile durations), unless otherwise specified (manufacturer was unwilling to provide the spec). Notice that ALL manufacturer's websites, except Skunk2, do NOT list the standard 1mm or 0.0394 in. valve lift spec for duration. Marketing is huge and only an uninformed customer does not understand that reporting the domestic duration standard @ 0.05 in. lift or advertised duration @ 0.015-0.020 in. lift is not providing fair comparative profile info between import cam grinds . No ramp/flank angles or ramp speeds are provided, except for Jun. All rocker arm ratios are stock at 1.55 for the VTEC lobe and 1.50 for the nonVTEC lobes. All recommend stock Honda specs for the valvespring installed height. Valve lash settings can be obtained from the manufacturer. Prices listed are from the manufacturer's link (MSRP) in US dollars.

I don't cover the specs of regrind VTEC cams available like Web, Gude, and JG. Web Camshafts makes very good quality hard weld cams ground to any spec you request. RS Machine (Exospeed) will not release the specs for their race or street cams when we asked . All of the aftermarket cams listed below are billet core, non-reground cams, unless otherwise stated.

STOCK GSR : b17a and b18c1 (Chilled Cast Core)

INTAKE lift - 10.6 mm,duration - 230 @1mm
EXHAUST lift - 9.4mm, duration - 227@1mm

1. ITR/CTR (Chilled Cast Cores)

http://tech.hybridgarage.com/tech/bseries.html (originally this table came from Frank Lin's old gspeed.com website and the legend of b16a section which is now 404)

- STOCK 1997-1999 ITR ($500-580/pr, ITR intake cam $250-290)

INTAKE lift - 11.5 mm, duration 240 @1mm
EXHAUST lift - 10.5mm, duration 235 @1mm

- STOCK CTR and 2000-2001 ITR (CTR intake cam $300-350)

INTAKE lift - 11.5 mm, duration 243 @1mm
EXHAUST lift - 10.5mm, duration 235 @1mm


2. Blox (no @1mm specs available)

( MSRP $750 US/pr for Tuner Series not Competition Series, Chill Cast Cores )


- Type A , Tuner Series($450-535 US / pr)

INTAKE lift - 11.7 mm, duration 247 @ 0.05 in.
EXHAUST lift - 10.7mm, duration 239 @0.05 in.

- Type B, Tuner Series ($450-540 US /pr)

INTAKE lift - 12.4 mm, duration 266 @0.05 in.
EXHAUST lift - 12.0 mm, duration 266 @0.05 in.

- Type HSL, Competition Series ($510-570 US /pr)

INTAKE lift - 12.6 mm, duration 255 @0.05 in.
EXHAUST lift - 12.5 mm, duration 256 @0.05 in.

no available specs for Tuner Series Type HSL or Turbo, Competition Series Type B , 10124 Race, or Turbo yet.

3. Buddy Club

- Spec 3 Plus ($549 US / pr)

INTAKE lift - 11.2 mm, duration 250 @1mm
EXHAUST lift - 11.5mm, duration 245 @1mm

- Spec 4 ($600 US /pr)

INTAKE lift - 12.3 mm, duration 269 @1mm
EXHAUST lift - 11.8 mm, duration 274 @1mm

4. 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. They require a VTEC/fuel controller like the Apex VAFC for tuning the idle and have an aggressive ramp and more aggressive nonVTEC lobes, despite the relatively mild specs on the VTEC lobe. Thanks goes to Steve at Johnston Research & Performance for the info.


INTAKE lift - 11.1 mm, duration 242 @1mm
EXHAUST lift - 10.32mm, duration 240 @1mm

5. Crane Standard Tappet & Race Only Roller Follower Cams

The specs listed on the Crane Cams website are at 0.05 in. valve lift. Thanks to Dave Maxwell at Crane for forwarding the duration @1mm valve lift specs for the Stage 1 cams.


- Stage 1 (part no. 2530010 - $773.33/pr)

INTAKE lift- 11.6 mm, duration 243 @ 1mm
EXHAUST lift - 10.8mm, duration 237 @ 1mm

- Stage 2 (part no. 2530012)

INTAKE lift- 11.99 mm, duration 248 @ 0.05 in.
EXHAUST lift - 11.6 mm, duration 242 @0.05 in.

- Stage 3 (part no. 2530016)

INTAKE lift- 12.39 mm, duration 254 @ 0.05 in.
EXHAUST lift - 11.99 mm, duration 248 @ 0.05 in.

- Crane/Ferrea Roller Cams (part no. 2530514 $629/pr but must also purchase Crane/Ferrea Roller Followers Set price - unknown. See comments below about using roller cams and standard rockers or followers)


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. This causes the effective rocker arm ratio to vary as the cam acts across the span of the pad. If you hold a Honda rocker arm so you can look at it from the side (looking through the shaft axis), you'll notice that there's an "arc" or radius to the rocker pad's configuration. This radius is quite large, so imagine the diameter of the circle it would be part of, were it extended. I haven't measured it, but the circle would be quite large ...something on the order of 2.5" or so.

In order to have the same valve action (as with the Honda rockers) from a Honda "type" camshaft, the radius of the roller in the rocker arm would have to be that same (large) diameter. Since there's no room for a roller that's that large, not to mention that the mass would be "extreme", any roller rocker arm that has a roller that's smaller can not provide the same valve action. This means that anytime you use the roller rocker on a cam ground for Honda rockers, you won't achieve as much area under the valve lift curve and the opening / closing rates will also be slowed considerably. Bottom line is that you will not make as much power with these roller rockers, as you would with the Honda rockers.

6. Crower VTEC Cams (Chilled Cast Cores)


Here are the cam durations @ 1mm valve lift which are not on the Crower website. Thanks to Brian Crower for providing these.According to Brian the reason why he did not provide the duration @ 1mm:

"The Toda advertised specs are at .0143", so that's why we adopted that number as our advertised number." All cams $642/pr.

- 63402's have the same lift but lopier idle and bigger intake duration than the 63402A :

INTAKE lift - 11.83 mm, duration 237 @1mm
EXHAUST lift - 11.81 mm, duration 228 @1mm

- 63403

INTAKE lift - 11.98 mm, duration 246 @1mm
EXHAUST lift - 11.83 mm, duration 238 @1mm

- 63412 N/A Race Core Cams

INTAKE lift - 11.84 mm,duration - (estimated) 260 @1 mm
EXHAUST lift - 11.81 mm, duration - (estimated) 252 @1 mm

- 63413 N/A Race Core Cams

INTAKE lift - 11.99 mm,duration - (estimated) 269 @1 mm
EXHAUST lift - 11.84 mm, duration - (estimated) 258 @1 mm

- 63411T Turbo Race Core Cams

INTAKE lift - 11.81 mm,duration - (estimated) 242 @1 mm
EXHAUST lift - 11.30 mm, duration - (estimated) 238 @1 mm

7. Dan Paramore


Dan Paramore did not get back to me to provide the duration @1mm lift specs when I had requested them. The intake ABDC closing spec is 52 degrees.

307 Cam (Race Only, $649/pr)

INTAKE lift - 12.07 mm, duration 248 @0.05 in.
EXHAUST lift - 12.07 mm, duration 248 @0.05 in.

8. Jun

Here is Jun's website:


Here are their max. lift and duration 1mm valve lift specs for the VTEC lobes :

- Type 1

INTAKE lift - 10.9 mm, duration 265 @ 1mm
EXHAUST lift - 10.0 mm, duration 268 @ 1mm

- Type 2

INTAKE lift - 12.0 mm, duration 267 @ 1mm
EXHAUST lift - 10.9 mm, duration 265 @ 1mm

- Type 3 ($890/pr)

INTAKE lift - 12.0 mm, duration 265 @ 1mm (Advertised 304)
EXHAUST lift - 11.5 mm, duration 265 @ 1mm (Advertised 304)

- Type 4($??/pr)

INTAKE lift - 12.5 mm, duration 265 @ 1mm (Advertised 304)
EXHAUST lift - 12.5 mm, duration 265 @ 1mm (Advertised 304)

Jun Type 3's have the reputation of eating valves if you milled the head, advanced cam gear timing more than 3 degrees, use oversized stainless valves, or use non-Jun or non-Toda valvesprings.

9. Piper

Here is Piper's website:


- BP285

INTAKE lift - 11.6 mm, duration 256 @ 1mm
EXHAUST lift - 11.2 mm, duration 256 @ 1mm

10. Rocket Motorsports (formerly Hondasaver, formerly EF-1)

thanks goes to Tom (aka Tbone) for emailing me the @1mm duration specs. ($750/pr or $990 with RM valvesprings as a kit). These cam lobes come Parkerized coated.


M20 and M21 specs (11.5-11.6 lift 274 advertised duration) not listed since we don't have their @1mm duration specs but are much less aggressive than M22's. M22 (street N/A)

INTAKE lift - 12.1 mm, duration 244 @ 1mm
EXHAUST lift - 12.1 mm, duration 244 @ 1mm

M23 (no longer available)

INTAKE lift - 12.1 mm, duration 252 @ 1mm
EXHAUST lift - 12.1 mm, duration 252 @ 1mm

M24 plain (no longer available)

INTAKE lift - 12.1 mm, duration 258 @ 1mm
EXHAUST lift - 12.1 mm, duration 258 @ 1mm


INTAKE lift - 12.7 mm, duration 263 @ 1mm
EXHAUST lift - 12.7 mm, duration 263 @ 1mm


INTAKE lift - 12.7 mm, duration 258 @ 1mm
EXHAUST lift - 12.1 mm, duration 265 @ 1mm


INTAKE lift - 12.1 mm, duration 270 @ 1mm
EXHAUST lift - 12.1 mm, duration 270 @ 1mm


INTAKE lift - 13.25 mm, duration 276 @ 1mm
EXHAUST lift - 13.25 mm, duration 276 @ 1mm


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. XX denotes 2 large nonVTEC lobes unstaggered like the Toda cams' nonVTEC lobes.

11. Skunk2 (Chilled Cast Cores)

www.skunk2.com now have the specs available. At the time of writing this article, they did not have the specs listed and I had emailed them via info@skunk2.com. Here are the specs provided by Dave Hsu at Skunk2 to me:

- Stage I (best price $712.50/pr, retail $797/pr, CARB Exempt pending)
INTAKE lift- 11.58 mm, duration 252 @ 1mm
EXHAUST lift - 10.8 mm, duration 249 @1mm

- Pro I+ for B series
INTAKE lift- 12.6 mm, duration 264 @ 1mm
EXHAUST lift - 11.9 mm, duration 264 @ 1mm

- Stage II (Not CARB Exempt, $700-725/pr, retail $849/pr)
INTAKE lift- 12.3 mm, duration 266 @ 1mm
EXHAUST lift - 11.8 mm, duration 262 @ 1mm

- Stage III - (race only, $700-725/pr, retail $849/pr)
INTAKE lift- 12.8 mm, duration 270 @ 1mm
EXHAUST lift - 11.8 mm, duration 279 @ 1mm

quote: I had an interesting discussion with Dave Hsu at skunk2.com :

These (Stage I) cams pass smog and do not require the use of new valvesprings (though recommended). B18C1 engine makes 17+ more to the tire on average.

Please inform your readers that bigger is not necessarily better. We have only seen 2-4hp increases when using toda B's or jun3's. Neither pass smog. Both require new valve train and in the case of Jun's, there is only a 3-4 degree margin of error before the valves grab each other and destroy the motor.

With the current (Stage I) cam our goal was to make as much power using stock valvetrain, while preserving driveability, reliability, and emission friendliness. 12. Spoon ($1045/pr)

Specs were kindly provided by Alan Chow at A&J Racing


INTAKE lift - 11.53 mm, duration 256 @1mm
EXHAUST lift - 11.13 mm, duration 245 @1mm

13. Toda

The advertised duration @ 0.015 in. lift can be found on their website. Thanks to Ali Jahed at AKH Racing for the duration @1mm valve lift specs.:


- Spec A's ($920/pr)

INTAKE lift - 11.6 mm,duration 250 @1mm
EXHAUST lift - 11.2mm, duration 240 @1mm

- Spec B's ($980/pr)

INTAKE lift - 12 mm, duration 255 @1mm
EXHAUST lift - 12mm, duration 245 @1mm

- Spec C's ($1100/pr)

INTAKE lift - 12.5 mm, duration 255 @1mm
EXHAUST lift - 12.5mm, duration 255 @1mm

- Spec D's ($ Not Available/pr, RACE ONLY )

INTAKE lift - 12.9 mm, duration - estimated 265 @1mm (Advertised 305)
EXHAUST lift - 11.9 mm, duration - estimated 275 @1mm (Advertised 315)

In terms of streetable cams, Toda D's have the highest non-roller intake lift in the market.If you rev past 8400 rpm, Toda valvesprings are required.

Interesting Comments by Endyn on Toda B-D Cams:

Valve problems can also be attributed to valve springs failing to control valve motion. 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. When the springs go soft, valvetrain separation occurs and the valves typically end up being "dropped" on the seats, rather than eased to their seats by the closing ramps on the cams, thus pounding out the valves and seats.

The potential damage from weakened valve springs is that great in my opinion...at least with Todas. I also don't think their valve springs are up to the task either. If you (have) to run cams like those, you can't run springs that "fit" in an installed height that's relatively "stock". You MUST run a spring that has at least 1.400" installed height with about 68-70 psi on the seat.

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. This tool fits in a collet on the Serdi machine and it not only machines the top of the guide, but it also machines the sides and step so the seal will actually sit lower. On heads running in engines with cams with .485" or higher lift, we always machine the top of the guides to maintain .060" clearance between the retainer and the seal. If you don't, oil is forced (by the retainer) through the guide, contaminating the mixture, and burning oil.

- Race-Only "Killer Cams" ($1,800/pr includes solenoid oil line plug)


INTAKE lift - 12.0 mm, duration 265 @1mm
EXHAUST lift - 11.5 mm, duration 255 @1mm

The profile is similar to spec C's. The biggest difference is the much reduced valve train weight. For full race you don't need VTEC components. They just weigh you down. To go beyond 10k rpm one better have some strong yet light weight piston/rods...

These race-only cams are light as hell, idles at 2000 rpm, redline at 12,000 rpm, and have a powerband from 5000-12000 rpm. There is NO VTEC LOBE. They have JUST 2 NON-VTEC BIG ASS SIZED LOBES FROM THE START. There is NO STAGGERED LIFT/DURATION for enhanced low rpm swirl filling as seen in the stock nonVTEC primary lobes.

When you look at the 305 degrees "advertised duration" spec for the Toda Killer cam, you should be aware that the duration at 1mm valve lift is only 265 degrees which is identical to the Toda Spec C.

So what's so special about them? Well, 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, but the ramp speed/angle is waaaay different.

As you already know, 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.

Lift and duration specs are not the only numbers to look at. Clearance ramp and flank angles or the steepness of how fast the valves open and close also is important to performance.

14. Zex/Comp Cams

http://www.zex.com or http://www.compcams.com/catalog/192_193.html

Thanks to Matt Patrick at Zex (Comp Cams). All $566.61/pr (the 57300 are by far the best bargain on the market).

- 57100, no valvespring change required:

INTAKE lift - 11.05 mm, duration 230 @ 0.05 in.
EXHAUST lift - 9.90 mm, duration 228 @ 0.05 in.

- 57200, valve spring change is required:

INTAKE lift - 12.45 mm, duration 248 @ 0.05 in.
EXHAUST lift - 11.43 mm, duration 246 @ 0.05 in.

- 57300, for racing only, high compression and major port work needed, for 10,000 rpm engines only:

INTAKE lift - 13.20 mm, duration 260 @ 0.05 in.
EXHAUST lift - 11.94 mm, duration 258 @ 0.05 in.
Posted in Engine Internal
Views 84258 Comments 0 Edit Tags Email Blog Entry
« Prev     Main     Next »
Total Comments 0


For the best viewing experience please update your browser to Google Chrome