Sr20det compression test

[ZeNkI S14]

I had my sr20 motor built by rpm in mt. juliet, tn. and had the motor bored .20 over i was just wondering would the compression be different vs. the factory sr20det? right now my compression is low. it reads 120psi across the cylinders. if you guys have any answers i would greatly appreciate the info thanks.

[RED_DET]

My stock sr20det read 150psi across the board a couple years ago. This was on a FWD SR though, I would assume it should be the same. I moved the thread over to the RWD section for better responses.

[duffman1278]

If it's still freshly built and you havn't had time to run it much then it should be a little low.

Let the rings break in.

[xrproto07]

Well usually when you are dealing with swapped sr's you gotta drive them a while and get them in operating temperature's to get good reading's on compression test's or a break in period...don't be alarmed on the low number's just yet

[Sil80315]

once the motor has fresh piston rings, they need to be broken in. Your not suppose to baby the sr during break in, your suppose to do 2,3, and 4 gear pulls at 70% throttle but let the rpms vary. A good break in will increase the compression numbers

[ZeNkI S14]

well i have blow by issues really bad and the motor has about 6 to 10,000 miles on it. and my catch can was about half full. the blow by is coming out of the intake pipe side of my bov. now i forgot to put about half a quart of oil back in the motor. would that also throw my reading off. right now the car is untuned as of right now, and that i was told by the guy that built the motor for me said that if it is dumping to much fuel in the cylinder that it would wash the rings out causing it not to seed properly. but my thing is that would a half a qt. low on oil give it that reading? i just hope my rings are not bad. and their goes another 500 something odd dollars back into it again.