Im replacing my valvetrain here in the next few weeks, and was wondering if it's worth throwing in the S2S2's before building the bottom end. It will be running flat bottom valves and a mugen head gasket on a B16, so I figure around 10.5:1 -- or is my money better spent on the bottom end for now?

Thanks in advance.

 

Also, car is running CTR cams right now. Any suggestions?

 

not enough c/r to make power... need at least full point higher then you have 11.5-12:1 for such aggresive cams

 

I'd tend to agree, though the cams won't cost you much power with that compression, they just won't perform up to expectation. Use one of the online dynamic compression calculators and you can get an idea of what your dynamic compression will look like.

 

save up and install a 1.8 or 2.0 bottom end and keep the cams you have now.

 

you need more compression or those cams are pointless, build the bottom end and leave the ctr cams for now

 

you dont more displacement you need more compression


[Modified by LsVTeCTuRBo17, 11:05 PM 2/11/2003]

 

Get some CTR pistons for a cheap bump in compression.

 

waste of money for install if thats not my final product.

 

So what is the recommended C/R for the CTR cams?


btw, let me know if you are planning on selling your CTR cams after the install.
email: nomanz57@hotmail.com

 

you dont need super high compression to run ctr cams or skunk stage 2 cams. that information is not correct. i have dynoed tuned those cams with all kinds of setups with all sorts of compressions and for those particular cams in question you dont need more compression then what a stock vtec motor puts out. more is better and will benift . but its not needed. and you wont lose any power by doing so. i hope this helps. good luck!

 

Need? No. You don't "need" super high compression to run skunk2 stg2 cams. I believe I said as much previously. The problem, if indeed we can call it a problem is the late closing of the intake valves on the high lift cams causes a drop in dynamic cylinder pressure. Now while you can still make good power and the problem can be addressed by raising static compression & fiddling with cam gears, it is something to be aware of when you're shopping for bumpsticks. Here's a link to a dynamic compression calculator. You'll need the ABDC spec of whatever cams you're looking at to calculate your dynamic c/r.

http://www.rbracing-rsr.com/comprAdvHD.htm

 

Here is an example using the cams that I currently run(Crower 63403):

GSR bore in inches 85mm = 3.346
GSR stroke in inches 87.2mm = 3.433"
GSR rod length 5.43"(137.9mm)
63403 ABDC 46

Now with a static c/r of 12.3, boost of 0, and altitude of 500ft(guess) my dynamic c/r is down to 10.94:1 w/ a dynamic cylinder pressure around 237PSI. That's a healthy drop and skunk 2 stg2 cams have a longer duration, though I do not have the ABDC spec for them handy.

Crower 63403:

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

Skunk2 stg2:

INTAKE lift- 12.3 mm, duration 266 @ 1mm
EXHAUST lift - 11.8 mm, duration 262 @ 1mm

The skunk2 stg2 cams are very kewl, I've played with them, though not in my car, but you need to be aware of what you're getting into with cams of this lift & duration so you can plan your build-up around them. Good luck.

 

What I was trying to say is that he would be happier with a 1.8 or 2.0 block.
The money he is goooing to spend he can just save and get a stock itr block and he would be alot happier and more reliable.

 

What is he going to do with a stock bottom end and S2S2's cams??? Nothing!