I have a 1994 GSR with about 150k miles on it..

My scores are..
154 149 151 155
these aren't exact on the dot.. but thats what i think the needle was pointing at. I did my compression test with a pretty hot engine.. i let it cool for like 30 min.. taking off the spark plugs wuz a bitch cuz it was kinda hot.

I let my car crank 5 times and let off to get each result.. i did it twice and i got the same results.


on another note.. my header and exhuast.

 

thats good numbers. nice car

 

i've been see'ing peoples scores and its in the 180~200 range... mine is only in the 150's.

i dunno if thas good or is that bad..

do all you people have higher compression pistons or someshit?

 

i think your supposed to crank it 7 times.. i forgot exactly.. check cspeedracing.com

mine was 220 across the board...

 

i do it 10 times, and all mine read 200-210. If you let it crank 10 times, then it will be higher. Worn rings tend to build up compression slower... and good rings build up alot compressioin in the first cranks.,
manny

 

u guys let it crank that much??
hmm...

my stupid mechani friend told me 5 times is good enuf.. and his mechanic buddy said at least 6 times.. and im like ****.. i arleady put back on teh spark plugs!..

okay... on monday.. i'll let it crank 10 times... it sounds like it hurts the engine tho.

 

There are a lot of factors in order to get an accurate compression results: the underhood fuse for the ecu or fuel pump needs to be removed, motor @ operating temperature, turn the car over 6-8 times with the gas pedal depressed while cranking. Your numbers seem to vary a little....are u burning any oil??

 

for the novice, you're just looking for numbers that fall close to each other. The range of the individual cylinder readings are far more important to you than a set of numbers to compare to factory specs. A compression test is easy as pie to do but hard as *something really hard* to do and net factory spec results on a fundamentally sound engine. And cranking more to get higher numbers is sorta kinda defeating the purpose of the test as a diagnostic tool. Rings a good amount of wear but no failure will show lower numbers to begin with and build the longer the engine is cranked. Course you could do it again and crank it for 2 minutes to make yourself feel better...

 

those are low, try a diff compression gauge just incase.

 

as long as the numbers are the same, you are fine. Those #s are definitely low, but similar to each other. Your motor seems healthy enough.

 

Time for a good cold air intake.

 

Do your compression test right after you shut your car down. Don't let it sit for 30 min next time.

Although your numbers are close together, they are still on the low side.

Tom