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Camshaft talk: school me

76K views 89 replies 35 participants last post by  hx40 
#1 ·
Ok i want to try to get all the good cams in one thread my goal is to find out which cam will give off the most percentage of power. Would like to stay in stage 1 and 2 cam profiles. I know every build will yield different power bands and peek power. But I want a general all around thread were I can see ok if I get this cam it will give me a minimum of 10% of what I'm Making now etc. I think by talking about the cam profiles it will give off the percentage rating of what the cam will produce. Or maby someone can school me and I'm thinking totally wrong and should be building the motor around the cams. Like finding what the cams are demanding from my motor, rather than finding profiles that will give me what I want.
 
#2 ·
Re: Camshaft talk school me

Most stage 1/2 cams should give around the same percentage gains for the same mods; listing ur setup and/or matchin it up with some others out there should give a general idea of what to expect with what. Here r some cam threads that popped up in a couple of quick searches. GL! :up:

http://www.k20a.org/forum/showthread.php?t=95853&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=97443&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=33949&page=5&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=36364&page=26&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=94492&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=93033&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=86949&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=69687&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=80895&highlight=camshaft+stage+best

http://www.k20a.org/forum/showthread.php?t=98615&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=95467&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=94181&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=91921&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=12262&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=88005&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=84258&highlight=best+drop+cams

http://www.k20a.org/forum/showthread.php?t=69786&highlight=best+drop+cams
 
#4 · (Edited)
These are roughly the 10 stages for all motor k series engines offered by www.SVMcams.com

0.49 inches (svm 111)
0.523 inches (svm 211 and svm 211.4)
0.533 inches (svm 311 and 311.4)
0.543 inches (411.4)
0.555 inches (511.4)
0.565 inches (611.4)
0.575 inches and so on
0.585 inches
0.595 inches
0.605 inches


and in mm

12.446 mm
13.2842 mm
13.5382 mm
13.7922 mm
14.097 mm
14.351 mm
14.605 mm
14.859 mm
15.113 mm
15.367 mm


That is the max lift specs, around these values

Naturally a 86mm stroke has limited valve relief so you cannot run a really big cam like on a k24 with 99mm+ stroke

Only way you could run a really big cam on a k20 block with k20 crank would be going turbo with aftermarket pistons.

Max gross valve lift might be the same between svm 211 and 211.4 but duration is different.

By covering the whole lift spectrum, we hope to help people who like to think outside the box.
 
#5 ·
Re: Camshaft talk school me

So would the 13.4 be classified as a drop in cam sense it's not as agressive as others stage 2 cams. 13.4 on intake and the 12.4 on exhaust. That would or could be a drop in right. Unless those lift specs are for as set of cams. Ps. Went to that website but don't know how to check pricing
 
#6 ·
Re: Camshaft talk school me

These were specs just for the high speed lobe (vtec lobe)

What you refer to as aggressive is not really based on the max lift but the ramps, meaning the opening and closing speeds and rate of acceleration for the valves.

That is why you can have a cam with a smaller max lift beating another with a higher max lift.

Its almost like judging NBA players based on their height instead of their actual statistics for points per game, etc etc
 
#7 ·
Re: Camshaft talk school me

O ok thanks for dumbing it down for me. So will you make any cams to use with stock valvetrain. I see what u mean they are using lift specs to sale the cams? By the way I am Looking for applications for a k24. That is another thing too. why is their not K24 specified cams I know the heads will accept any cam, but wouldnt the displacment be able to make use of diff ideas in cam duration and profile over the k20
 
#8 ·
Re: Camshaft talk school me

Nikos- the new SVM cams sound amazing. A lot of this cam spec stuff flies over my head, but I'd be interested in a good cam recomendation for road race use in a stock k24a2 with bolt-ons. Some fat mid-range power and a good even powerband would be key.

I'm not in a position to purchase any at this time, but both me and other users may benefit from this info long term, as people seem to always be asking for the "best cams" for their setup. Plus a basic K24 build with OEM pistons is a pretty popular and affordable setup.
 
#9 ·
Good points.

Correct. That is why I use the .4 to show that this cam is for 2.4L+

The manufacturing model is small batch prototypes so making any cam out of what designs we have available takes the same amount of effort vs doing all of them the same profile.

The 111 profile is for OEM valvetrain. I could make a 111.4 for you to test vs a 111 in the future. Part of the reason why I think that the 111 will work well with k24 as well is because the Redline on the k24 is usual lower.

The relationship between the cam and the spring is all that really matters. Trying to make the most power with a drop in cam is challenging but it makes more sense for a k24 than a k20.

Once the stock springs cannot support the valvemotion, the result is bounce and usually that is where your dynograph goes flat or downhill.

You might be surprised but demand on drop in Cams is very low among all cam companies.

I have also drop in cams for turbo and supercharged engines.
 
#10 ·
Re: Camshaft talk school me

Hmmm ok. Really getting interesting now, I have searched for a hour and can't find another company that makes a k24 specific cam to compaire to. Unless u know of any. Now with that said. It might cost to much to make specific litter cams for other companies. Also it might be the same reason why k24s show the same percentage increase as k20s do because the cams don't utilize the displacment. I think I Will try you on your offer with the drop in cam k24 specified. I really think your on to something and might want to protect from copy-ers.

Unless drag cartels 2.2 cam is ment for 2.4 if so it's only you and cartel
 
#11 ·
Re: Camshaft talk school me

:eek:ok so read the posts, i know your talking 2.4L here but i have a k20a i want to go n/a not interested in going 2.4/2.0 conversion like a b20/vtec, cause i want reliability and i want to keep my R together, i.e. block, and head, tranny together.

if i upgrade my valvetrain and piston rod combo what camshafts could i run that are better than skunks?

thanks.

the whole cam lobes make no sense to me in terms of lift and what not.:eek:
 
#14 ·
Re: Camshaft talk school me

:eek:ok so read the posts, i know your talking 2.4L here but i have a k20a i want to go n/a not interested in going 2.4/2.0 conversion like a b20/vtec, cause i want reliability and i want to keep my R together, i.e. block, and head, tranny together.

if i upgrade my valvetrain and piston rod combo what camshafts could i run that are better than skunks?

thanks.

the whole cam lobes make no sense to me in terms of lift and what not.:eek:
We will have to get some people with there cams to come in here and post before and after dynos so we can compare cams, liters and builds. Would be nice to get this thread a cam reference thread
 
#12 ·
Re: Camshaft talk school me

cam lobes are the "bumps that make the valves move.

lift is how much off the valve seat the vales will rise(even though technically they are dropping into the cylinder it is referred to as lift).

duration is simply how long the valve is off the valve seat a certain height(usually .050 or something like that).
 
#17 ·
Re: Camshaft talk school me

So for a high compression 2.4L, whats more important, lift or duration?
The answer to your question is "it depends."

I think a better question is, with the appropriate supporting mods..."what effect does increasing lift have on the powerband?" and vice versa "what effect does increasing duration have on the powerband?"
 
#18 ·
Need helpi dont have a huge budget but whats the best cams for a built k20 head and a crv stockblock nitrous i.will use will be tuned but not use it alot just have it there. I want cartel 2.2 but there expensive. So whats next for alittle cheaper.
 
#21 ·
shit and to think i paid $175 for mine, and sold them for $250 lol
 
#41 ·
lol, jdm4lyf works here at AFH. He's a tech.

he was posting from his phone, hence the horrid grammar and spelling.

he's been talking to ryan, rich, and myself about his motor build and is conflicted by what he wants to do. Were trying to explain and show him the way. I Had no clue of these posts til he just asked me some q's and telling me about this thread.

he's learning
 
#42 ·
Ok so let's get back to it shall we :)
Can we talk about difference between cams with large lift VS long duration and what the gain is? I'm under the impression that high rev, short stroke motors use long duration in order to "inertial supercharge" NA motors?
Large lift with shorter duration used to gain torque in the midrange but sacrifice peak HP at rev limit?
And then there is the Really Big profiles that I can only imagine are for large displacement high rev motors??
Any info appreciated :up:
 
#44 ·
if what I remember niko saying..short stroke engines don't allow for as long of a duration as long stroke engines do. High revving engine do make better use of valve overlap though IIRC.
 
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