Interesting...

I did a compression test today.

131/131/130/130


I guess I am now a little concerned. At least they are close to each other.
I think a leak down is in order


Edit: Just corrected my pressures for altitude.

153/153/152/152

 

185/185/185/185

 

Did the test again for about the 10th time however I did two separate test because there is not any official instructions as to how many times to cycle the starter

So first test is with 4 turns of starter and second run is with 7 turns

1) 175-176-174-186 (four starter turns)

2) 189-190-190-196 (seven starter turns)

OK every on, which run is most accurate, #2 I hope is it because of only 7 psi diff.

Nonetheless, #2 is how I allways did the test and with same results from 1st time.

I need expert opinion here thaks

 

the rule is you should be at top psi by 4 revolutions of the motor.. just watch the needle jump 4 times and thats your number.. thats the industry standard.. its a little odd, the one being higher than the rest. but nothing to worry about.. your fine and have good numbers..
03-04 evo's thats a good number..

 

My 2003 is 188,190,188,190 with 55,500 Miles on the clock.

 

i have checked 3 diff evo's with diff. years, and i come up with 150-155 range.. last i heard, dont quote me but im pretty sure the shop manual says around 150 for our cars.. i wonder why so many cars are reading this high.. itzwolf how did you perform your test and what gauge are you using..

 

Static cylinder pressure readings will be affected by upgrades such as cams, changes in cam timing, etc., so don't assume that they should all be equal.

 

yes and with cams you would get lower readings..

 

Not necessarily.

 

Not sure the actual gauge, it was my buddies kit that has leakdown also.

I have 272 cams and no advance/retard of my cam gears. Car was hot, let sit for about 30 minutes, the test was performed with throttle 100%. I forget how many turn overs to be exact this was a few months ago. I am at roughly 5-10ft above sea level too.

Also the car consumes no oil.

 

how do figure that.. longer durations, higher lifts, promote the valve to be open longer.. thus not giving an accurate reading.. in cases of aggresive cams you would want to do a running comp. check. then you would have better readings than just cranking the motor over..

 

I'm still somewhat bothered about why it takes at least seven starter turns to get the peak pressure when everyone else does fine with 4 turns.

Another concern is the higher reading on #4, it's either 1, 2, and 3 are low or 4 is just unusually high.

Who knows, car runs fine - a little knock prone (probably 4) and was a little underpowered off the lot but does just fine now with mods.

 

Yes....I have 272/272 cams and mine read 175, 165, 165, 175....at 3000 ft elevation. My car is damn quick for the mods and the elevation I run at.