Quick compression question
 

I glanced through the FAQ and how to buy page but i didnt see the answer. What should be the compression on a cold S4 TII,, my friends have one sitting in their shop all torn down so i grabbed my 19mm socket and gave it a couple turns :) Came out to around 25 on both rotors. I read that N/A should be around 30 and turbo should be a little lower right?

Cranking speed and oil viscosity due to temp has a significant effect on compression numbers. To compare with factory numbers (6.0 kg/cm2, 85psi) the engine should be warm, the throttle plates wide open and cranking at 250rpm. The chamber differential (1.5 kg/cm2, 21psi) is also very important.

Spinning it by hand ain't going to tell you much beyond the basics, i.e. your apex seal integrity.

Here's a thread with some of my testing a while back right after I built my own digital tester. http://forum.teamfc3s.org/showthread.php?t=38420

Cheers

Hand cranking can no way give you a valid number.
Hell, we don't even know how lubricated the insides are?
You can stuff Vaseline in there and pump out some fantastic numbers! :eek:


-Ted