looking at an l98 motor out of an 89 trans am.... what should the compression be in all the cylinders if i am going to do a compression test??

 

My LB9 with 150 K mi. on it was 160 psi +/- 3.5% which I think is typical.

 

cool beans thanks!!!!

 

The actual numbers are not as significant as the maximum difference between the numbers. A lot of variables are involved when performing a cranking compression test. Most engines with a "decent" cam will produce a lot lower compression numbers while cranking, but a lot higher actual (dynamic) compression while running. As long as all the cylinder results are within 5-10%, things are probably all good.

 

thx for that info Vader! I just swapped my cam and I'm going to be doing a compression test hopefully later on tonight when I get out of work.