FAQ : B Series Cam Guide

FAQ : B Series Cam Guide

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We’ve tackled the Cam Guide or How to Choose Cams Guide for the LS1 series of engine in our How to Swap LS1 segments at great lengths. Today we’ll be looking at the B series Honda engine and showing you what you need to look for when selecting a VTEC cam, whether you are after NA or forced fed power.

The easiest part of selecting a cam from our B series cam guide is figuring out what kind of power you want to make. All-motor power or from the forced fed variety, determining what kind of horsepower is right for your application is the first thing to do.

What to know before our B series Cam guide


 

  1. Engine goals
    1. What is the PEAK horsepower you are trying to achieve?
    2. Where do you want the power to begin in your powerband?
  2. Knowing the camshaft terms
    1. What is Lift? Duration?
    2. What is Overlap?
    3. What is Lobe Separation Angle?

To kick off our B series cam guide, we’ll be looking at bullet point 1.2, which is where do you want the power to begin in your engine’s powerband? Do you want to gain power from your aftermarket camshafts in the upper rpm range or do you want gains in the lower to midrange of your B series engine?

What TDC should look like
What TDC should look like

Low rod ratio engines like the stock B18 make a lot of power compared to other engines with higher ratios, because of the piston geometry at work. If you own a VTEC engine, it’s almost a foregone conclusion that you want more power up top where the airflow can work with the variable cam timing of your engine.

Ways to move the powerband higher in the RPM


 

Increase Duration – Answering the question of “What is Cam Duration” in our B series cam guide, is cam term number 1 duration. Duration or the period of time that the valve in question is being held open, is a vital part of knowing what your camshafts do. Increasing this value or the amount of time the valve is held open, shifts the peak torque and peak hp location to a higher rpm.

In a B series engine, the absolute peak torque and peak hp number also increases in parallel with the camshaft duration. More duration means the cam will hold the valve will stay open during the cranks rotation. The longer the valve stays open the longer the time the cylinder can be filled. This is important at high rpm, since there is less and less time for the cylinder to fill.

The image above shows a comparison of two different camshafts with 20 º of increased duration ( line graph with no dots) vs a camshaft with the same lift and LSA values, but lower duration. Notice the differences in power and where the differences begin to see what camshaft duration does for your powerband.
Increase Cam Lift – B series camshafts can also benefit and move the powerband further up in RPM by increasing camshaft lift. Cam Lift is the value assigned to the aftermarket cam in question, and tells you how far the valve is lifted from it’s seat. Increased camshaft lift will also result in higher torque and horsepower numbers.
Increasing camshaft lift can do good things as well as bad for your B series engine. You want the ideal amount of lift that won’t conflict or cause problems with other components of your engine. Too much camshaft lift however can help contribute to valve float and can cause catastrophic engine failure.
You can also change the camshaft lift values by changing the rocker arm ratio in your B series cylinder head.
Lower Lobe Separation Angle (LSA) – Honda VTEC engines can benefit from lowering the gap of camshaft LSA. The LSA or lobe separation angle refers to the angle between the intake and exhaust camshafts. The LSA is important for camshaft purchasers for two reasons.
  1. Valve Overlap
  2. Intake and exhaust valve closure delay
A lower LSA or tighter LSA results in more overlap at engine Top Dead Center (TDC). A higher LSA or making the LSA larger will result in less overlap at TDC.

What is Engine Overlap?


A good primer to read about engine overlap can be found in our How to Tune your 4G63 cam gears article here. Overlap is 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.

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.

B16AG1

You can increase overlap in one of two ways.

You can either increase the duration of your B series camshaft, or you can reduce the LSA without changing the duration of the camshaft in question.

Keep in mind however because you are lowering the LSA instead of raising the duration, the smaller LSA cam may make more peak power but will produce a lot less lower end torque.

The B18 engine in natural aspiration have typically done well with camshafts featuring high lift, long duration, and big overlap. The B18 turbocharged or forced fed engine do well with high lift, short duration, short overlap (wide LSA) cams. If you are modifying a B16 however, you will want a high lift, short duration, short overlap cams, because of the B16’s higher rod ratio.

Be aware of what the camshaft will do to your powerband before making your purchase.

Things to do when upgrading your B series cams


 

Upgrade or check valvetrain – Make sure your valvetrain or at least your valvesprings are in good shape, and rated enough to handle the camshaft you are installing. Do not simply skip over this step in valvespring inspection, because coil bind can occur.

 

zexcam

 

 

Even if you are installing a camshaft that the company claims does not require spring upgrades, you will see some valve float. Valve float is when the spring has fatigued at high rpm and basically fails to push the valve back into the seat. Valve float causes damage to your cylinder head and valvetrain components in a least case scenario. It can cause your pistons to slam into your valves in the worst case scenario. Don’t let this happen to you.

Make sure your valve springs are set to the correct installed height of (1.320-1.325 in. or 33.53-33.66 mm) and check that the lost motion devices (for VTEC B series engines) are all present and in good shape.

Always use assembly lube on the cams during install and follow the Honda oil change maintenance schedule.

Check and double check that your B series engine is at TDC during the timing belt installation.

Always use a new or upgraded timing belt to make sure that the engine operates at a high level for a long period of time.

Make sure the valve lash is set to the manufacturer’s specifications and that the cam gears and journals were orientated the right way.

 

B series DOHC Camshaft Tips


– 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.

We’ve also taken some time to list out some of the more popular B series camshafts, as voted by our customers and My Pro Street users. We’ve broken this down into a format similar to the one submitted by Joey B on SiCivicforums, please enjoy!

Integra Type-R(Through 1999 Spec)

Int-240 dur. / 11.5mm lift
Exh-235 dur. / 10.5mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms. Mugen Valve Springs can also be used.
Description: These are great, reliable cams for the money. You can pick up a set for as little as $500.00 new if you are lucky! They will give good gains from midrange all the way until 8400rpms. These cams have stock idle characteristics.

Civic Type-R And Integra Type-R(Integra Type R 2000/01 Spec)
Int-243 dur. / 11.5mm lift
Exh-235 dur. / 10.5mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms. Mugen Valve Springs can also be used.
Description: These are great, reliable cams for the money. You can pick up a set for as little as $550.00 new if you are lucky! They will give good gains from midrange all the way until 8400rpms. These cams have stock idle characteristics.

Skunk2 Stage 1
Int-252 dur. / 11.5mm lift
Exh-249 dur. / 10.8mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms. Skunk2 Valve Springs can also be used.
Description: These are very underrated cams. They do cost around $100-$200 more than the Type-R cams but they also offer much more duration and will give more power than the Type-R cams.

JUN Type 1
Int-265 dur. / 10.9mm lift
Exh-268 dur. / 10.0mm lift
Valve Springs to be used: Tough to say. I have never seen anyone use this cam. The characteristics say that a stock B16A/GSR valve spring could handle these cams for use up to 8200rpms. Any operation above that and I would use ITR valve springs or even JUN valve springs.
Description: Again, I have never seen these used. I have no clue on the power these cams will deliver but it should be similar to that of a Skunk2 Stage 1 cam, although they are very different cams. These cams have stock idle characteristics.

Spoon Sports
Int-256 dur. / 11.5mm lift
Exh-245 dur. / 11.1mm lift
Valve Springs to be used: Integra Type-R. These cams are wild enough that you should not be using the low 8200rpms rev limit. If using these cams past 8800rpms(why would you) I would think that Port Flow or even Toda valve springs would work but I don’t think these cams will make much power after 8400rpm.
Description: Another somewhat rare cam. Will show definite gains over that a Type-R cam and very good gains on a stock B16A/GSR motor. Stock idle characteristics from the few users I have seen use them. I would recommend using Spoon cam gears with these cams.

JUN Type 2
Int-267 dur. / 12.0mm lift
Exh-265 dur. / 10.9mm lift
Valve Springs to be used: Integra Type-R up to 8800rpms or JUN valve springs for all operations. These cams are wild enough that you should not be using the low 8200rpms rev limit.
Description: Another rare cam but a few people have used it including JSIR. Cams will have just as much midrange gain as the big-brother JUN Type 3 but will start to slack off over 8400rpms when the Type 3s are still making power.

Skunk2 Stage 2
Int-266 dur. / 12.3mm lift
Exh-262 dur. / 11.8mm lift
Valve Springs to be used: Skunk2 preferred but Port Flow will work as well. These cams are wild enough that you should not be using the low 8200rpms rev limit.
Description: The new top dog of the cam world. This will become the most common aftermarket (non OEM) cam in the US when they start getting distributed more. These have a very similar power band as the JUN Type 3, with less cost and better reliability (I said the “r†word). Not huge midrange but very good gains from 7000rpms all the way to 9000rpms(peak is usually around 8000-8200rpms). These cams have stock idle characteristics, thus making them the ultimate street/strip cam. I recommend using Skunk2 cam gears with these cams.

JUN Type 3
Int-265 dur. / 12.0mm lift
Exh-265 dur. / 11.5mm lift
Valve Springs to be used: JUN preferred but Port Flow works as well. These cams are wild enough that you should not be using the low 8200rpms rev limit.
Description: Until the Skunk2 Stage 3 this was the best high-end performing cam on the market. The JUN 3 and Toda B were the two fighting out for the top dog when it was just JUN and Toda

Skunk2 Stage 3
Int-270 dur. / 12.8mm lift
Exh-279 dur. / 11.8mm lift
Valve Springs to be used: Skunk2.
Description: A race only cam. Not to be used on the street, if they are you should pull the head every oil change to make sure everything is OK.
________________________________________________________________________
Following cam measured with 0mm of lift:
Civic Si(1999 Spec)
Int-265 dur. / 10.5mm lift
Exh-267 dur. / 9.6mm lift

Integra GS-R
Int-274 dur. / 10.7mm lift
Exh-276 dur. / 9.6mm lift

Crower 400
Int-279 dur. / 10.7mm lift
Exh-280 dur. / 9.6mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms.
Description: This is a weird cam. I would call it an OEM replacement cam. It fits in between stock B16A/GSR cams and Type-R cams. There are not huge power gains to be had with these cams but you may notice a small difference. These cams have stock idle characteristics.

Civic Type-R And Integra Type-R(Integra Type R 2000/01 Spec)
Int-278 dur. / 11.5mm lift
Exh-280 dur. / 10.5mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms. Mugen Valve Springs can also be used.
Description: These are great, reliable cams for the money. You can pick up a set for as little as $550.00 new if you are lucky! They will give good gains from midrange all the way until 8400rpms. These cams have stock idle characteristics.

Crower 401(NA Version)
Int- 282 dur. / 11.3mm lift
Exh-277 dur. / 10.5mm lift
Valve Springs to be used: Stock B16A/GSR if using stock 8200 re-limit. Integra Type-R if using rev limit over 8200rpms. Crower Valve Springs can also be used.
Description: This cam is almost identical to the Type-R cams. A little more duration overall but that is traded off with a little less lift on the intake cam.

Crower 401-T(Forced Induction Version)
Int-280 dur. / 11.8mm lift
Exh-276 dur. / 11.3mm lift
Valve Springs to be used: Crower.
Description: One of the only true boost cams for B-Series Hondas on the market. This cam is designed for low overall to prevent blow-by and to save boost. This is typically associated with lower duration and high lift but cam lobe separation is also a factor with these cams.

Toda Spec A
Int-290 dur. / 11.6mm lift
Exh-280 dur. / 11.2mm lift
Valve Springs to be used: Integra Type-R up to 8800rpms or Toda valve springs for all operations. These cams are wild enough that you should not be using the low 8200rpms rev limit.
Description: One of my favorite set of cams. Toda does not actually mix and match their cams but they are similarly tied when it comes to power. The Toda A will offer the midrange gain of a Type-R cam but the high-end gain of the Toda B cam. These cams will have gains from midrange to 8800rpms with peak gains concentrated on 7000-7800rpms.

Crower 402(Both Regular 402 and 402-A, 402-A is milder off VTEC)
Int-297 dur. / 11.8mm lift
Exh-287 dur. / 11.8mm lift
Valve Springs to be used: Crower.
Description: There are two 402 versions offered. The 402 is the regular version and offers better midrange power than the 402-A. Both are similar on the high end of the cam and will create similar peak power numbers. They will make peak power around 7900-8200rpms and have nice gains all the way up to 9000rpms. Stock idle is attained with the 402-A but the regular 402 will have a slightly “bumpier†idle than stock. I recommend using Crower cam gears with both sets of the 402 cam.

Toda Spec B
Int-295 dur. / 12.0mm lift
Exh-285 dur. / 12.0mm lift
Valve Springs to be used: Toda but Port Flow will work well too.
Description: My personal pick. These cams have the most midrange gains out of any B-Series cam when they are tuned right. They have the same midrange gains of a Toda Spec C and the same top end as the Toda Spec A. They are in tight competition with the Skunk2 Stage 2 and JUN Type 3. Those care are more concentrated on top-end, peak power gains.

Crower 403
Int-295 dur. / 12.0mm lift
Exh-293 dur. / 11.8mm lift
Valve Springs to be used: Crower.
Description: Crowers wildest cam. The 403 has good midrange of the 402 cam but with a little more top-end power. They will make more power above 8200rpms than the 402 cams. Like the 402, the idle will be “bumpier†due to the aggressive non-VTEC profile.

Toda Spec C
Int-295 dur. / 12.5mm lift
Exh-295 dur. / 12.5mm lift
Valve Springs to be used: Toda
Description: The ultimate cam. This cam mixes the midrange power of the Toda B cam with the top end of similar to that of the JUN Type 3 and Skunk2 Stage 2. Power gains from 4500rpms all the way to 9000rpms. This is truly, the best overall cam for both midrange and top-end power.

Toda Spec D/Ericks Racing
Int-305 dur. / 12.9mm lift
Exh-315 dur. / 11.9mm lift

That does it for our B series cam guide, please take a look at our B series camshaft selection in our store, or leave us any questions or messages below.

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