Did a compression test on my SR...

[Jesse SR20]

Results as follows-

#1 - 170#2 - 175#3 - 170#4 - 170

I let the engine give about 5-6 pulses on the gauge. Is that correct ? I've heard you're supposed to do 4, and I've heard to go untill the gauge stops.

BTW, this is on a cold motor out of the car.
Modified by Jesse SR20 at 8:22 PM 10/1/2004

[SpeedRacer1]

Warm up the engine. Remove all the spark plugs. Then do four compression strokes (aka four needle movements) at wide open throttle. Your numbers are too far above the proper specs, but at least they are consistant.

Standard pressure should be around 156 psi, minimum limit is 128 psi.

[Jesse SR20]

Yeah, all the plugs were out. I'll do it again, and stop on 4 pulses. No real way I can warm up the motor though, since it's out of a clip, and sitting on a roller cart.

[Jesse SR20]

Ok, test #2 results-

#1- 160#2- 155#3- 160#4- 162

This time I only cranked the engine through 4 compression strokes.

*EDIT* Damn it, I forgot to hold the throttle plate @ WOT. Oh well, with numbers this consistant I doubt there's any concern.

[Hijacker]

worst compression i saw was on an L28 that was bored and stroked to over 3.1. All cylinders save for one read over 280. He was wondering why he burnt up a valve, or why he was knocking when he hit the nitrous. I'm surprised he didn't have detonation before the nitrous

[daz1320]

When I tested my motorset I got 60,60,90,110. The numbers were so low I went and bought a new gauge.I got the same #s after the second test .After I got the motor running I tested when it was warm and got 157,160,159 and161.

[Hijacker]

sometimes if you put a drop of oil in the cylinder, that will raise the compression back up. The oil helps the piston rings make their seal if they've been dormant for a long time