Someone Somewhere must have bought it from authorized GM try to get them involved I think that would be your only chance. Better chance if there was a manuf' defect but personally I have found GM to stand way behind there products. Had a newer SS camaro that spun main bearing, finally got them to replace it under warranty. That motor had 12k miles on it when it broke a crank same area where bearing spun. GM wouldn't do anything, machine shop found the cause to be a bad harmonic balancer. Also on GM crate motors racing and marine use void warranty so try to leave that part out..

Don't think electrical1's source would give that up. Vinny, what was the name of the place you purchased them from?

I put two 454h0 create motors in a 29 fountain 5 years ago ,with blowers. The boat still runs great to day. I would say It is not the motors problem, You have something wrong. Bad fuel, jetted wrong , to much timing. Intake leak or some thing. On a big block 5 and 7 are the first to blow. Most of the time due to lean cond. Let us know what you find out.

He was told a lean condition was the problem. Went out and bought larger holleys and same problem developed after the 2nd install. I'm curious to know how the bore & piston mic's out to the rest.

Give what up the marine usage?

Would think they would help him out to at least be able to charge him labor. If a shop couldn't tell me for sure why 3 motors broke they wouldn't be putting in the 4th.
Rick

Just 2 Rick. The 2nd did the same exact thing as the 1st.

I am up in MA and if there is anything that I can do to give you any help please let me know.

Jon

Sorry I read the first post wrong, thought two blew up and 3rd was ticking..my bad! I'd like to see what the pistions and also plugs looked like. If it was a lean condition and both sides were set up the same they should have been giving some signs- pinging, temps, something?? I'm thinking if nothing is wrong with the exhaust on that side then maybe a manuf' defect. Reguardless of seller I would push for some help from GM if it wasn't user/installer error or caused by exhaust. Buying carb's you didn't need stunk.. hope things start going better!
Rick

well nothing yet. everyone is taking there sweet time thinking about what to do and of course i'm the one out of the water while there having fun on there boats. after reading all the advise I just want to clearify 1 thing, we didn't put 3 motors in one after another and watch all 3 blow. the boat has 2 motors. the first one blew about an hour in to the first ride after replacing both motors. we replaced that one again
with another and that one lasted about 5 minutes into the second ride. The 3rd one hasn't blown yet but just sounds awful after about 15 minutes, it's ready to go. STAN (CIG1988) has been a lot of help and is ready a great guy, great to talk with. A credit to this site.