ok so as you guys know i have been cursed with motors in my boat. I was wondering if my boat could be doing this. what if my motor and pump are not lined up correctly. would that cause the motors to gernade?

or is iti just suck with boats. or maybe my engine guy can not build a boat motor to last.

also i have a friend in town that has a vortec 454 with the roller stock cam that he will give me a killer deal on. it is a late model engine though. will my oil pan fit on it. will it work in a jet boat?

anyway lets here some ideas on what the hell is going on. i cant keep buying motors every season.

1 If ya haven't done anything major to the boat, don't see how that  would be causing your motors to keep going south.  2 How is your Maintenence   3 Your engine guy?  How well do ya know him, and how long has he been in biz Seems to me if you only get ONE season out of a motor, sumthin aint right   4  your last questions I don't have a clue, I am sure someone else will chime in 

I dont see a misalignment taking out a motor. ( a driveshaft yes ) Did your engine guy build your motor with bigger tollerances on the bearings and cylinders? Jet boat motors have ALOT more load on them CONSTANTLY than a typical car motor.

he said he knew all the clearances for a jet boat. i dont know what everything is set at exactly. i just dont know

The only thing I can think of is if there was not adequate endplay for the driveline, causing the rear main bearing to fail, and debris circulating through the engine.  If you call me we can discuss what was common between the 3 engine failures.  Phone number was sent by PM on the other site.

Man that sucks. I had to switch my builder on my last motor. aka speedomotive. They screwed so many things up. when I called them about no oil pressure after a rebuild because of their stupidity on the motor before that one. They didn't have a clue. so I yanked the motor and pulled the pan and the oil pump fell off and landed on my foot. They forgot to bolt it on . I had it with them at that point. How does a high rep engine builder forget to bolt down the oil pump. . Later I found out they use china parts, rods cranks cams ext even when the customer pays and asks for top of the line parts. To be safe I would advise having someone else look at your damaged motor to see if it was builder errors.

Sounds like your heads were not set up correctly to your cam. What are your cam specs. what kind of lifters, rocker arms, push rods, springs, spring rate? What style keepers? If you throw a nasty cam in your motor with stock heads and assy you will have major problems.

You run that thing HARD too though Tony, I'd probably spend a little more and get some better hardware in that top end.  Just my .02

Sounds awfully cheap, but might be cutting you a lot of slack since he's built it before.......and before......and........

Ray

Marine cam and stock everything may be your problem. If its a big cam. you may need better lifters and a different spring rate valve springs. I would run some roller rockers as well. Try and find out the cam specs =the lift at 50 thousandths

no that was in my friends hallet. we put a 383 in it and flattend the cam during the break in cause the water pump failed. same builder though