Hey guys just ran a compression test on my LS1 from an 02 camaro. Im new to the LS platforms and just want to make sure i got a good buy. This was sitting in a garage for two years and we ran a cold compression test with motor outside of car. NOT in any specific firing order but this is what we got.

150
150
165
165
180
180
180
180

are these good numbers? also it seems as if the oil has dried and gunked up. took the valve covers up and it was gunked. stuck a camera down to inspect cylinder looks. should i do a motor flush?

 

10-15% variance is typically safe. That motor is a little more than that. Depending on what you want to do with it, if it was a daily driver, I would drop it in without hesitation.

 

planing on tracking the car for drift use eventually. just want to get this thing up and running reliably this is going into my nissan 240sx

 

Getting that engine in and out of the Nissan is a PITA. Your compression numbers are just over the edge of acceptable. It's relatively easy to do a basic overhaul now: Rings bearings, valve job, etc. I would do it now and be done with it. Then it will be good for for a few years without worries.

 

how much would that cost me estimated?

 

 

 

looks like a lot of carbon build up. yeah just want this to be reliable. where are the ring bearings? yeah im looking at valve jobs and they look pretty cheap. would you reccomend getting new valves and springs and lifters?

 

Not a whole lot of carbon, i've seen so very much worse. No such thing as ring bearings, he means the piston rings, rod bearings, and main bearings. With those numbers, I highly doubt it's the piston rings, I would be looking at the valves , I probably wouldn't even mess with the lower end.

 

if it was me,I would just re-condition the heads and be done with it.

 

i was like ok ive never heard of ring bearings lol. well thats good to know. i checked the springs and rockers and nothing looks broken or collapsed. i was thinking about a valve job but my budget is getting tight. figured id put some seafoam for now to get it on the road and upgrade the heads later??

 

by recondition do you mean a valve job? or just clean out everything

 

He means a valve job. If your budget it tight and you don't mind pulling it out later down the road, it will run fine for now. Those numbers aren't going to cause a problem.

 

That engine is sludged up, the piston rings are probably pasted and that is why your reading are low. You need to either pull it apart or use something in the oil to clean it up.

 

Before you take it apart:
1. put some light oil down the plug holes and re-do the test. Cylinder that show much higher have bad rings.
2. just to be safe, do a leak-down test to identify leaking valve seats and head gaskets.

 

yeah i figured ill upgrade later and find some different heads from a junkyard and do a valve job on those. After flushing it out multiple times i should still have a good amount of power with those numbers still correct??

 

was thinking of flushing with seafoam. you think i should take the heads off and wipe down all the gunk off then clean everything with carb cleaner? or will the seafom in the oil suffice?

 

Your power should be fine, I wouldn't expect it to be down on power at all.

 

awsome. as for cleaning the heads is that a good idea while its out? also was told 14w 40 diesel oil would be good for those compression numbers

 

I wouldn't use seafoam in a lawn mower! If you want safe cleaning put a qt of ATF dexron iv 6 in there run the engine easy for a few 100 miles, repeat until its clean.