455 Olds

[LoganWC34]

Bought a boat with a 455 olds. Runs, but did a compression test. Heres the results :
cylinder 1 135psi

cylinder 3 90psi

cylinder 5 0psi

cylinder 7 120psi

cylinder 2 0psi

cylinder 4 140psi

cylinder 6 140psi

cylinder 8 0psi

Ultimately there all low, but what would cause no compression? Boat was never winterized so its missing the freeze plug ( i have a new one otw). How hard would it be to fix??

 

[FENDERFAB]

Could be a variety of things. Head gaskets, Could be head issues with the valves. Could be a fucked cam. Could be messed up pistons. Start tearing it down from the top and see what you find.

 

[4xFoorOffroad]

Borescopes are pretty reasonably priced these days. Can check it out before even turning a wrench if it’s going to take awhile to get around to taking it apart.

 

[84Prerunner]

Multiple cracks in the block if it really froze or rust holding valves open. Pulling valve covers will pretty quickly tell if there is a valve issue.

 

[LoganWC34]

Could be a variety of things. Head gaskets, Could be head issues with the valves. Could be a fucked cam. Could be messed up pistons. Start tearing it down from the top and see what you find.

tore off the intake/valve covers. Head gaskets and valves are my issue. Did a leakdown test and figured that out. Now my issue is finding a machine shop that wont r@pe me in money for a valve job

 

[FENDERFAB]

I would just search for a cylinder head shop on google and call around and get some pricing!