I have just over 1300 hours on my 440's . Compression is within specs on all but one cylinder, which is just 5p.s.i. under. They seem to run good. So, not all marinettes had one reverse rotation motor? I haven't paid attention yet as to whether my motors are opposite or trannies.

Bret as long as your within 10 to 5 psi you okay. If the wheel aint broke don't fix it. I have seen chryslers that have been taken care of go as many as 2500 hours before any major surgery required. I luv them chryslers.

Hey Doug, No didn't hit with timing light before tear down. It just looks as though this is the cause, 3 other pistons had bubbling burn marks on them and one other was just starting to come apart. Real tough motors, we ran her hard for several hours during sea trial and then again a couple of times after we got her back here. Lucky we didn't knock a hole in the block or do more damage than we did. Oh yeah no hour meters on the boat although the gen has one and shows 565 on it and by the looks of everything else on the motors, inside and out it would be my guess not many more hours on the motors either.