Looking for cranking compression data + cam specs. If you have done a compression test and recorded cranking compression please list data and the cam specs.
Phillip

 

I'll start....

Comp Cams 230/230 XE 114lsa + 11.4:1 = 215-220 psi
Comp Cams 230/230 XE 110lsa + 11.4:1 = 210-215 psi
Comp Cams 232/238 XER 111lsa + 11.25:1 = 200-205 psi

 

You should also list the intake centerline as well in helping compare different cranking compressions with different cams/compression ratios.

Jason

 

Jason,
Do you by chance know what your car has for cranking compression with that big 240/236?
Phillip

 

Phillip, no, I sure don't. I never did a compression test on that motor. Sorry...

Jason

 

Jason,
How about any of the motors you have built or worked on?
Phil

 

Comp 218/218, .528 lift, 114 LSA, 114 ICL, stock compression ratio:

225 psi with 6 degrees of advance
215 psi with 2 degrees of advance

 

Comp 232/232, .575 lift on 114LSA, 110icl,
10.8:1 cr = 200-205 psi

 

TR 230.8/224.3 .576/.563 110.8 LSA 110.8 ICL, 10.8:1 compression ratio

197-203 psi

 

What were the parameters for the compression tests? 3 cranks, 5 cranks, WOT, Closed throttle?

 

Interesting results....Compression test needs the TB to be open and 3-6 cranks until you see a full reading.
Phillip

 

I had all the plugs out, WOT, and I cranked it until there was no increase in pressure.

 

This has to be standardized in order to be able to accurately compare one cam from another. Typically it's 5 cranks at WOT.

 

I did a search and found this old thread...figured I'd add to it.

I did a compression check on my 2002 Z28 with a Thunder Racing 227/224 reverse split cam and 10.8:1 compression. I think it's 114lsa with three degress of advance ground in. I had seven cylinders hit 240 and one hit 245. They all hit over 150 on the very first crank. Can anyone explain why these are so high? I've been doing a search and haven't found any with numbers like that.

I used a Mac gauge so it wasn't some crappy Autozone off brand or anything. The heads are 5.7L milled .038 Am I running more compression than I thought?

Chad

 

I did to of my cylinders last night with the throttle body closed and only got 155 160????

 

About 4 Cranks And Motor Warm, 175 In Each Cyl.

 

You can crank it 5 times or 500 times and compression will be the same so that is not a factor. Just crank it until there is no more increase in pressure on the gauge.

It is best to do it while the engine is at operating tempurature but we all know that tight spaces and hot headers equal burnt hands and forearms.

 

Yes but only one plug was out and your throttle body wasn't wide open was it?