120-120-119-118 compression results, need part list for shortblock rebuild

[Verticaljump1]

Lol, my compression results were 120-120-119-118, so the car obviously needs a rebuilt motor. I've got my plans down pact for the head, but I have no idea what I need for the shortblock other than the aftermarket rods and pistons. If anybody could run a list of the parts I'll need and where I can find them that'd be great. I considered an engine kit but I didn't know if it would include EVERYTHING I needed to do the shortblock. I've got the machine work covered, I just need the parts. And what should I replace as far as the front case goes. I want to see if I can get this done for about $1200, machine work/assembly will be $600, so the rest lays in the parts I'll need. Thanks~Brandon.

 

[biglady112]

A leak down test will yeild accurate results of the condition of the motor. What is your elevation in whyoming. I live in denver and my 9:1 motor fresh off the rebuild only got me 135 across the board. My friends 115,xxx mile 1995 GSX put in between 125-130 across the board. After cams it went down to 115-120 accros the board. So The fact that they match is a good sign.

Let us know your elevation and then we can determine from there.

Wait I just checked. Your the guy who bought the 25/44 from me. I am sure everything is ok. If they match then it may not be as bad as you think.

Steven

 

[Verticaljump1]

Lol, yeah what's up Steven. We're at 6000ft. elevation up here. The air is thin . I'm thining about a completely stock rebuild, with the exception of arp main studs, arp main studs, and forged pistons. I need something that will hold up the wrath of a 60-1 w/ cams, so probably not more than 475whp. A stock rebuild could even take that couldn't it?

 

[JohnnyC]

475 WHP on a stock rebuild is pushing it....

 

[PieEyedPiper]

I agree that since your cyls are so close to each other that your problem might not be a problem at all. How did you perform your compression test? Was the engine at normal operating temperature (192F - 204F)? Did you perform a wet test? what lead you to perform a compression test to begin with? What ailments is your car suffering from?

I'd just hate to see you a) rebuild when you don't need to and b) rebuild and end up right where you started. If you're bent on rebuilding I'd do something a little more interesting with it, especially if you like the sound of 475hp.

 

[siceclipse]

I see nothing really wrong with the motor. Its always common to look for the correct #'s but its more important that all the #'s are within 2-3psi of each other. I had the same #'s as you and was freaked out cause they were low, but my friends dad said its fine cause they are all even with each other. Later i found i was doing the test wrong (wasnt at WOT when cranking) and figured where the 30-35psi i was missing was. but again, you should do a leak down test to be sure. I just find it funny that all 4 are reading the same and all 4 are blown (rings or valves)

 

[marcmsj]

i'm also still trying to find out my problem... i'm getting 135 115 110 135 and a wet test only yields about a 10-15psi difference so i don't think it's my rings. if i could only find a leakdown tester but everywhere i go, no one knows what the damn thing is

 

[oldman]

Lol, my compression results were 120-120-119-118.

I suggest re-checking your test procedure and try a different tester because like already mentioned, the numbers are low and close across the board.

 

[marcmsj]

I suggest re-checking your test procedure and try a different tester because like already mentioned, the numbers are low and close across the board.

and what's my advice? already tried 2 compression testers and i did everything as i was supposed to.

 

[Verticaljump1]

I just realized I didn't do it at WOT, we just cranked it over and tried. I decided to do the compression test cuz I knew I was going to get a new motor and I wanted to see how my stock one would do. I'm going to get my battery charged and then give it a go and see how it runs. The car also wasn't warmed up.

 

[Verticaljump1]

I'm thinking about just doing a completely stock rebuild, with the exception of arp rods bolts, main studs, and head studs, and 9:1 pistons.

 

[oldman]

and what's my advice?

Perform your own leakdown.

 

[marcmsj]

Perform your own leakdown.

knew you were gonna say that

know where i can get the gauges? no one around here has even heard of a leakdown test. i went to a few local parts store and they were all clueless...

 

[oldman]

I think Summit have them or check any on-line mechanic tool out fit. If you find one, let me know.

 

[oldman]

Nothing a little search can't find.

 

[siceclipse]

told ya something was fishy. go retest and come back and tell us of your 173psi across the board. and when you are done with that it would be nice to be rewarded with reputation points

 

[marcmsj]

Nothing a little search can't find.

thanks.. i'll have to try it out and keep you guys posted.