actual engine compression PSI

[markvwguy]

Hey Volks,

This might be more of an engine performance or engine management topic with high performance AC engines.

We go through and build engine combos get them running N/A or turbo EFI and carburetor. We talk about compression ratio and high compression. We talk about heads and flow/velocity, ratio rockers, lift, stroke, air fuel ratios, EGTs and detonation.

I haven't seen any Shop Talk about actual cylinder PSI after engines are running and making the HPs . I did a compression test on my 2007cc 8.2:1
the cylinder PSI was 180-190 PSI. N/A engine.

I was surprised to see such high PSI. Out of all the things listed above, actual cylinder compression I didn't think about except for peak cylinder pressure and timing for tuning.

In building performance engines is there any data out there for the best actual cylinder PSI for performance and tuning which dove tail in with AFR and EGTs and detonation?

What's the actual compression on your performance engine combo? I know there's very smart Volks out there who might have some insight.

Mark

[bad62bug]

What Cam.

[markvwguy]

78mm crank
CB 2236 cam
5.5" I beam rods
AA 90.5 P&S B pistons
1.25 to 1 rockers
8.2:1 ratio
set up for turbo in mind; my next bad idea