Thread: SR20VE compression test numbers...

All plugs out is definitely better especially when you get into really high compression motors. People do it different ways. I prefer to put less stress on the starter and have them all out at the same time, unplug the distributor so you get no spark or fuel and do the test. You definitely get faster cranking with it and you can hear how many compression cycles you go through as the other cylinders wont do anything.

The more you guys talk, the more I think I had all of the plugs out last time. I can't remember? I must be getting old or something. I bet I get 220 PSI when I re-do it.

Ashton, as I was cranking I do remember thinking the starter had a MUCH different sound to it this time.

Get 4tester and put it in each cyclinder Lolz

Starting with cylinder # 1 in order to 4, i got 235,211,215,210. This test was done with engine on the ground using a car battery. Can anyone explain the amount of variance in the first to last cylinder?

Starting with cylinder # 1 in order to 4, i got 235,211,215,210. This test was done with engine on the ground using a car battery. Can anyone explain the amount in variance in the first to last cylinder?

Thanks to eggman for a nice flywheel

so me that looks like good numbers, keep in mind that the motor is cold, i would consider that a good motor. the difference i cant say for sure but im going to guess either lack of rotational power or it just being cold. maybe when the engine is running then everything will loosen up again

Those numbers seem pretty good for a cold motor. A hot motor would give you different/better numbers.

The variance in between the cylinders could be from a number of things. If you powered the test off of a car battery that was not under constant charge or full charge, testing of cylinder one may have drained the battery enough to have given you lower readings on the next three cylinders. Also, you may have done more compression strokes (cranks) on the first cylinder. Another reason for lower numbers on some cylinders could be worn piston rings, valve seats or a bad HG seal. Judging by your numbers, a HG issue is unlikely. To test the rings, add 1 full tablespoon of oil to the three lower psi (as tested) cylinders. Crank the engine a couple of times to distribute the oil and then re-test the cylinders with a fully charged battery, making sure to do equal cranks for each cylinder. If the numbers go up signifigantly, it shows that the piston rings are worn, or more likely that the cylinder just didn't seal properly because the engine was cold. If adding oil does not improve the compression numbers, more than likely, it is because of a leaky valve seat. If the spark plugs that were in the engine were neither fouled nor covered in oil, I would chaulk all of this up to a cold engine.

Those numbers, while not perfect because of the variance, seem healthy to me. If you are anxious, you could try the test again, with the oil in the combustion chamber and a fully charged battery.

Thanks for the feed back guys, i will retest again tomorrow, i was also thinking the battery was a little drained from the first to last and i didnt account for amount of cranks.

I comp tested mine with stick cams and got 245,245,243,245

Motor sounds like it is band new