Your Compression Numbers

well i went and bought a compression tester about a month and a half ago. i was expecting it to be somewhere around 150 ish in most of the cylinders. did the compression test on the cylinders a few times, just to make sure that they stayed the same. so i've come up with 190 psi in each cylinder. i've been wondering if thats above average or not. has about 150000 miles on the engine, every thing is original as far as the engine itself.

how i performed the test was to run the car until it was at oporating temp. took all the plug wires and plugs off and out. then put the gauge to each cylinder, letting it turn over about 5 times with the throttal opened. that resulted in 190 psi consistantly in each cylinder with very little varriation in each. i got 180 psi with the throttal closed. so that should be a good indication the combustion chamber is well sealed.

so if you have done a compression test on your engine, list the pressure results and mileage. i'm curious to see how everyone elses is.

190 is not bad at all....i still have to test mine

thats b20 correct? That sounds pretty good

i got 200 psi

throttle closed, engine cooling, 89k

150 psi cold motor, throttle open, 120,000

i have an A20, not a B20. but wish i did.

i've always done it with the engine cold, the throttle open, and the injector fuse pulled out.

yesterday i checked and #1-4 was 180, 180, 172(ish), 175.

158,000 miles. bottom end is all original, head is rebuilt.

Last time I did a compression test was after I rebuilt the engine in late 05' to make sure everything was good. Every cylinder tested at 175-180 before the rings had a chance to seat in.

i havent tried doing one when the engine was cold. it was said to do it when the engine has reached its oporating temperature. i may try doing one when its been sitting. i'd like to see how the numbers change.

i think you're supposed to do it with the engine hot. i just don't like turning the plugs when the head is hot.

anti seize tends to keep the plugs from messing anything up i've found if you are working on a hot engine.