new to this forum need your input

[jet454boat]

I currently live in mesa az and i have a 18 ft jet boat with a 454 bbc i had a shop rebuild the motor last summer and about a month ago at the lake i cruising about 4300 rpm when a valve ethier broke but i think the keeper came loose so i took it back to the guy and he said i over revved it!!! i have talked to other shops and they say overrevving it would throw a rod... is this possible for what my engine builder said???

[DelawareDave]

1. Who diagnosed the problem?
2. If he (or you) didn't take a valve cover off to determine if the actual
problem is with the valves, then you (and he) are just guessing at the
problem, and therefore unable to say what caused the damage.
3. How long of a WRITTEN warranty do you have, and what does it
specifically cover?

[QuickJet]

I currently live in mesa az and i have a 18 ft jet boat with a 454 bbc i had a shop rebuild the motor last summer and about a month ago at the lake i cruising about 4300 rpm when a valve ethier broke but i think the keeper came loose so i took it back to the guy and he said i over revved it!!! i have talked to other shops and they say overrevving it would throw a rod... is this possible for what my engine builder said???
4,300 rpm in a jet boat is a cruising RPM. You did not over rev it!!!

[jet454boat]

he took the motor apart and the valve is in the piston and he tried to say it looked like a came out of the water and overrevved it... i have the piston at my house now... i also have a rev limiter on the motor

[Daytona100]

Pics please.

[502 JET]

If the piston to valve clearence was too tight over reving could do this.Did the pushrod bend?Did the spring or retainer break?Intake or exhaust valve?

[jet454boat]

it was the exhuast valve and i know the spring wasnt broke cause i looked at that but thats all he would tell me

[502 JET]

You could have run lean and melted the valve or if it was a two piece valve it just decided to seperate.
Not many engine builders want to assume responsibility (this would cost them money).Always quick to put blame on the operater (not on the parts they sold or serviced for you).Even the best most expensive parts break/fail.
If it was my money I would want to know for sure what went wrong if your builder wont tell you then I would think it was something they f-up on.

[wickedfab]

that sawks mang...
i was cruzin at 5g and broke a rocker...right at the trunion,it wedged the valve open and you know the rest. half the valve in the piston the other half in the exhaust, stupid rocker...also two weeks before i blew the motor in my 96 gmc.

[Cas]

could be wrong valve springs also, they may have bound up and let loose at the wrong time. Lots of things could have caused it.