Did a compression test last weekend while doing some much needed maintenence else where on my car.

The setup is 81.25x89 LSV, OS P30's, milled head which brings the CR to roughly 12-12.1 as i've measured.Cams are small, 1st gen B16's

The motor's been daily'd for over 2 years and still running strong. The results showed 240 across the board however i failed to get the motor warmed up before doing so....

I presume the reasoning is to let the pistons/rings expand to gauge an accurate measure so i should yield a higher reading once i retest post warm up, correct?


Thanks in advance...

 

Those compression numbers sound about right for the CR. And to your question, yes you should warm the motor up before performing a compression test.

 

Good to hear, i felt they were kinda low however i know the cold test didnt help + the dynamic compression could make a variation from one setup to the next but all else aside the rest of the test i performed to the best of my knowledge...WOT, decent gauge, 5 cranks, double checked each cyl, etc...

 

If your getting those numbers cold, thats a healthy motor.

 

Well its suprising cause i'm buring oil and unless its the valve seals which were new when assembled i was pegging it on the rings.... otherwise my suspicions are telling me its a result of a fumble i did when assembling the block where in one cyl i installed a piston that i managed to drop on my garage floor (yeah i know major no no)

The piston had a small light scuff in one spot where the oil ridges were so i took some high grit sand paper and smoothed out the slight imperfection by sanding the spot a few strokes in one direction only.

 

oil control rings could be taking a **** in one of the cylinders...did you use ls rod bearings??

 

Yes however the motor rarely see's high revs since its mostly driven in traffic where im shifting at 4500 or sooner

 

Leakdown test it.

Compression testing is only testing the top ring, you need to test the middle ring.

Compression is good tho, you're probably burning a little bit of oil because of vtec..are you just checking your oil, or do you see it coming out your exhaust.

 

I have to replace a quart a week + there's carbon stains from exhaust coating my back bumber and right tail lense as evidence its burning oil unless im wrong...

Its a full open exhaust.. ITR header, test pipe, 2.5 in to a fartcan so i dont know if the absense of the cat has anything to do with that or not.

I'll do the leak down and see what i get

 

All Motor I will just ask you here instead of starting a new thread.
Im having trouble finding a compression gauge that reads over 300psi do you know where I can find one? My motor pegs the gauge before about 3 compression strokes cold.