Opinion on compression results for 502
 

How is it going new to this forum and looking for some helpful opinions. I am looking at a 2000 Baja 272 with a 502 in it with 400 hours on the motor. I just had a compression test ran on the motor and the results are as follows

#1 - 140
#2 - 135
#3 - 140
#4 -140
#5 - 140
#6 - 125
#7 - 135
#8 - 130

Now I am pretty comfortable with those numbers being a mechanic all my life but I want to know everyone else opinion on that one low cylinder. I know it is not that low but should I be concerned that it is the only low one. I also have oil samples on the way being that it is a 12 hour drive from me. Thank you in advance for any replys

If all you do is cruise with a little bit of full throttle now and then, I would leave it alone for another hundred or two hours. Just keep maintaining it properly. Those numbers are only down a little bit and they are pretty consistant.

They are pretty much within the 10% spec from highest to lowest and about what I would expect for a 400hr engine. The results can vary a little bit if the engine has not been run for a while. I wouldn't let it scare me away, but might use it as a way negotiate off another $500-1000.

Thanks for the replys. I appreciate your help

What's the other engine read? Just kidding. Sounds reasonable for the hours. A good friend of mine works for BG automotive products. Believe it or not they have some oil and fuel addatives that work awesome on used engines. Not your typical over the counter products. They call on a lot used car dealers offering lifetime warranty. I would never believe how well it worked until I tried it for myself in 2 different applications. Amazing how the fuel addative cleans the valves and the oil addative works it's way into the ring glands and helps increase the comp. Again, I know this sounds like a sales person talking however it truly works.

After running the oil addative in my 76 chevy 350 it bumped the comp up between 7 to 12 pds in 4 of the 8 cyl. This was doing the procedure 2 and only takes 20 minutes per. It's really interesting to pull apart the filter and inspect afterwards.

Hot or cold? #s are not that bad for the hours, I would do a leak down and see where it is going.

Sounds like he's a ways away from the boat however I'm sure he'll be on that one soon. I would have to bet that it's a combination of intake, exhaust, rings, bore. Still decent numbers though for 400 hours. From all my old boat engines it always seems to be around that 500 hours that's time for a tear down. As you mentioned though a leak down is always good.

The numbers are from a cold engine