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Can an 81 be rebuilt

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deuce_is_wild

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"Long story short I lost an en

"Long story short I lost an engine this weekend. #1 piston blew apart and is in pieces on my '88 3300 Tiara(Friend lent me a scope to look inside) She was re powered in 2001 with 8.1 MPI (385hp)and has 370 hours on them.

I talked with a machine shop. They say, sorry we will not touch them, the 496 cu in long block is a junk engine. Just not strong enough to be rebuilt. Go buy a base engine and start over. Better yet go get a set of 502s and do both.

A Crusader Dealer said he never rebuilt any, he just replaced three base engines in the last couple of years.

Crusader said they have never heard of any body not wanting to rebuild a 496. It is a relatively new engine and there is not allot of them out there compared to the 454.

At this point I don't know what to do. Find some one who will rebuild it. Just buy a new base engine, or move to a different re power option.

Any one else hear similar or have experience here.

Thanks in advance."
 
"Deuce, I can't help you o

"Deuce, I can't help you on your question however I will give you something to think about. I was looking to buy a Blackfin 29 that was repowered with 8.1 high output engines. Before I even went to look at it the owner was forthright and told me that one engine has a strange knock under load. Not there at lower speeds. He said alot of people had ideas what it was but no definate answer. These were 2003's! Coincidence or a problem with the 8.1's I don't know. Engines have to last longer than 370 hrs. I know of a guy in Delaware who is selling a set of 454's that have 100hours on rebuilds. He repowered his boat with diesels because of the ethanol and fiberglass fuel tank issue. One other thing, The 8.1L engines are being discontinued soon. I can't remember when the year is going to be but I think it is 2009. "
 
"A piston can certainly be rep

"A piston can certainly be replaced, provided the cylinder is not damaged. Because of the close tolerances on this engine Crusader does not offer oversize pistons or rings.

GM does not sell the block bare, only as a longblock assy.

AS far as the 8.1 being too weak to rebuild... It sounds like he just doesn't know enough about it to want to do it. That is because the failure rate on these engines is so low, he has not had a need to rebuild one yet. There aren't near as many 8.1s out there as there are 454s, but they have been out there for seven years, with very few failures."
 
"I have not heard of many fail

"I have not heard of many failures either. The machine shop claims to have re powered a few and they were not happy with the length of service after the re power.

The web is littered with 454 rebuilds but no long blocks. At this point I'm waiting for a quote from the Crusader dealer for the base engine plus install. I would hope that there is a clue as to the cause when the old engine gets torn down. If there was water intrusion from a leak, at least that may restore my confidence in the base engine.

Thanks for the replies.

Crusader gave me a part # for the base engine."
 
"New to the thread - went sear

"New to the thread - went searching for clues on the internet as to why my 1988 Luhr's 342 with 454's would not generate more than 2900 to 3000rpm (12mph) on our first trip offshore last weekend. A little history - boat was moved from fresh water enviroment (Smith Mtn. Lake)in mountains of VA to saltwater enviroment in Charleston, SC this spring. Up on the lake the boat would push 3800 rpm (22 mph at WOT and cruise at 18 mph at about 75% throttle) with no problem. Engines run excellent - about 150 original hours on each but haven't had a tune up in several years.(just wasen't used much by prior owner) Stock carb's and distributor that have never been rebuilt because the boat has run so well. The boat was disassembled (bridge and helm) for shipping south and I'm wondering if there's a way to check if throttle cables are opening throttles all the way at WOT after re assembly of helm. She just seems to be lugging or plowing and won't get up on plane even with trim tab adjustments. Any ideas as to which direction to go in would be appreciated.
Thanks-
Hatrassr"
 
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