I just did a compression test this last weekend... was wondering if this is ok. I have JE forged pistons from HRC the low compression ones.... This is a brand new built engine and i did some searches in the forums and noticed that most are at about 180....are those stock pistons? we haven't broken in the engine yet so could this also be because the rings haven't seated yet?

Was the engine fully warmed up? What compresson ratio do you have? 8.1:1 or 8.8:1? If the motor isnt full warm, the #'s will be lower. Also, it needs to be fully broken in for a bit higher #'s also..Give it at least 1000-1500 miles.

They look fine for cold numbers.

Yeah, 150-160 cold, 170-190 warmed, on JE 8.8:1's.

As long as it's all even like that, you're perfect.

i've gotten these same numbers, regardless of the car, engine, whatever.

my stock engine, before i blew it was exactly 150 across all 4.
my stock engine, after i blew it was 150, 120, 0, 20.
my rebuilt engine, before starting it up for the first time, was exactly 150 across all 4.
my rebuild engine, after 3000 miles, was exactly 150 across all 4.

my dad's car, a 2000 Merc C280 was exactly 150 across all 6 cylinders.

my friend's 1993 Audi 90CS was exactly 150 across all 6 cylinders.

my friend's 1995 300ZX was exactly...


...you get the idea. something tells me that there's something wrong with my compression tester.

ner i think u need a new compression tester dude!

you're supposed to release the pressure in it after each test! ha. just kiddin w/ ya

heh!!!!!!!! maybe its stuck der! lol.... yeah, and when you switch cylinders, you have to actually move the gauge and screw it into the according spark plug hole.

you are pressing the gas pedal to the floor when you do the test, right? That will make a difference