compression tested a motor i have. these were the results 230, 220, 195, 180. i cant remember if that was in exact order, just those were the results though.

 

if those are accurate, then it's a problem. You've got a variation of 50psi between cylinders. However, the 230 seems way high, unless you're running 13:1 compression, or so...

 

thats what i thought too. its a BONE STOCK 94 GSR motor. its the same guage i used on my built GSR motor that read all 4 cyl dead even at 295psi a few weeks back. i got 12.5:1CR on my motor.

 

diagnose on basis of compression test?

give us a break?!!

what prompted you to do the test? loss of power? any smoke?

what does it sound like? drive OK?

thanks,

t..

 

just got the wrecked car. curiousity is my basis. i didnt know i had to have a basis to post a ? on honda-tech. the motor would run if i tried to start it. just kinda weird that 2 cyl would b high like that and 2 low. but for a BONE STOCK gsr motor its got way above ave cyl pressure on 2 of the cylinders. i think stock compression for GSR is 210-230 and this is a 94 with a supposed (theft recovered b4 i got ahold of it) 100k on it

 

whoah!

if people didnt have a basis to post, this would be a crap place to come. jsut stupid **** posts about nothing!

but your post is about something, a comp test - which looks pretty bad!!!

damn hard to diagnose though, without other info.

on the basis of the test though, id say it could be the something to do with the cams timing?

beacuse two are way high and two are way low...

have you pulled hte rocker cover? an signs of anything unusual?

HTH,

t..

PS i wasnt having a go at you, it is just a big ask to "give me a diagnosis" based on 4 numbers and nothing else...

 

well unfortunately i havent taken the motor outta the car yet. so i have yet to really diagnose anything, just wanted some thoughts from everyone. like i said its really weird how 2 r high and 2 r low, but the 2 highest are above factory specs. last time i heard the car run, it did sound like it needed some valves adjusted but its not goin to bring that compression up that much. i should just get it outta the car and tear it down. id rather get rid of it though.

 

Carbon build up in engines adds to compression.
An old Buick V8 that I helped put into my friend's C10 had compression readings waaay above normal. The engine was stock, turned out that the carbon in there had built up pretty thick.

Fuel additives that are supposed to clean your injectors and cylinders, can cause thick carbon buildup to break loose in large chunks. It's really up to chance how the carbon buildup comes off (or if it does). But if something like that happens, then you've got large pieces of debris being processed through your engine.

So maybe someone added some of that FI cleaner LATE in the engine's life. It could have had a dramatic effect on 2 cylinders, but not the others.

Hypothetically speaking.

 

Did you have the engine warmed up before you did the comp. test? You're not going to get accurate readings on a cold engine.