What could be causing this high compression, how do I lower it? Is it good that it's this high, I read that most stock Chevy's are in the 120 range...

When I tested the first time on a hot hot hot engine my # 4 tested 125 and my #6 tested 160... after running some water though my intake and warming the engine a few days later they are all at an even 160...

Can someone decipher the riddle?

 

If you look at my times they are a full .5 seconds slower than a stock 2.8 should run, I trying to find that time in my setup... the computer checks out everything is OK according to a Snap-On scanner...

 

did you do the test right, most people don't. run it with the plugs out and the throttle open. all the readings should be within 10% of each other. the actual number doesn't mean that much. 160 isn't high and 120 isn't low, all would be considered in the normal ranges, but the deviation is too much.

 

160 is not high. My '91 350 showed 150-160 psi when I checked it. There is a great article in this month's Chevy High Performance Magazine (Crank It!, September 2002), that covers this exact subject. The article states that a good range for a performance street engine is from 175-190 psi. There is also a side-bar that tells how to check compression.