sr20det - just did a compression check

[iammikeol]

Car was warmed up on idle for only 5 minutes. Just ran a compression check test on a friends sr20det, all cylinders came to around 120 psi. Added oil to one cylinder to see what would happen, results were: from 120psi to 150psi.

Bad rings? Piston failure? Should I retest?


car seems to run fine, no smoke from exhaust

[ForeignMuscle]

Check the FSM for acceptable compression readings. I would think it is just ring wear if the oil raised the reading.

Is the car low on power?

[iammikeol]

you have to push the accelerator gradually to accelerate quickly, if you bury your foot on the pedal quickly it seems to struggle to speed up like a bit sluggush

FSM is around 150 psi correct?

so the rings may be the problem?

[rcdad123]

the rings are going bad. as for the sluggish acceleration, sounds like a tuning issue.

[jr_ss]

128psi is low spec per FSM. Anything below that needs a re-ring.

[iammikeol]

turbo wastegate hose had a crack in it and was overboosting the motor, stock t25, on stock tune stock redtop.

could this of caused the rings to go bad, what else kind of damage could of been done?

[Croustibat]

That kind of things make pistons melt and det to death usually due to running lean and way too much timing (yes, even with a stock tune). Your rings look toast, so while you are changing them, check the head and pistons for det / melting marks. check the head and block are still flat too.