Looking For A Jet Bote Engine

[Chili Palmer]

My son bought a 20 foot Carrera jet boat last summer, earlier this season he hit a shallow section in Parker and sucked up a rock that destroyed his impeller. He took it to a shop in Havasu to fix his jet and have the guy go over the engine and figure out why it leaks so much oil. In the process the mechanic found out that one of his cylinders has no compression. He told him that to rebuild his 454 it would be about $5,000 and to build it up to a 496 he's looking at $7,000, and either one of them is about 6 months out due to him being backed up this season. Do these numbers sound right? I know some of you ballers that spend $40K - $80k on your multiple Whipplecharged engines every season or two, but I feel for him. His last boat, a Commander, ended up with a cracked hull. He's got a conscience so he doesn't want to sell it to someone knowing that the engine is bad, and if he does sell it with a bad engine he's going to take a serious hit on what he can sell it for.

Does anyone have a good engine ready to go, or have a reputable go-to builder?

 

[rivermobster]

Price doesn't sound outa line, but I'd give Barry a call....

@obnoxious001

 

[GRADS]

Olds 455 is the preferred motor of choice for jet boters.

 

[GRADS]

Here ya go

455 Olds Big Block - boat parts - by owner - marine sale

455 BBO engine, runs excellent. Holley Fuel injection system, HEI ignition, Bassett headers, starts right up, no leaks, very clean, and it runs perfect. Hear it run jet boat edelbrock 454 350 sbc...

sacramento.craigslist.org

 

[4Waters]

If he wants to step up to a 496 then he needs to find a wrecked HD with a BB. It will be 4 bolt main, 1 piece rear main, steel crank (I think), everything he wants, different heads for a carb set up (I don't know if his heads will bolt up) and he is set

 

[Fastdadtsmith]

@namba860 has some parts laying around. IMO 5-7k isn't out of line, but it all depends on long term goals.

 

[Nikwho]

If he wants to step up to a 496 then he needs to find a wrecked HD with a BB. It will be 4 bolt main, 1 piece rear main, steel crank (I think), everything he wants, different heads for a carb set up (I don't know if his heads will bolt up) and he is set

Steel crank not needed, if you're building a 496, as you'll be swapping cranks anyhow.

 

[4Waters]

Steel crank not needed, if you're building a 496, as you'll be swapping cranks anyhow.

Confused. Why would you change a 496 crank out for a 496 crank. Maybe I am missing something.

 

[Nikwho]

Confused. Why would you change a 496 crank out for a 496 crank. Maybe I am missing something.

You wouldn't. Chevrolet didn't put 496's in HD trucks(did they?) I probably misinterpreted what you were saying. My statement was regarding if one were to source a 454, then it wouldn't matter what crank was in it if you were looking to build a 496.

 

[TrollerDave]

My son bought a 20 foot Carrera jet boat last summer, earlier this season he hit a shallow section in Parker and sucked up a rock that destroyed his impeller. He took it to a shop in Havasu to fix his jet and have the guy go over the engine and figure out why it leaks so much oil. In the process the mechanic found out that one of his cylinders has no compression. He told him that to rebuild his 454 it would be about $5,000 and to build it up to a 496 he's looking at $7,000, and either one of them is about 6 months out due to him being backed up this season. Do these numbers sound right? I know some of you ballers that spend $40K - $80k on your multiple Whipplecharged engines every season or two, but I feel for him. His last boat, a Commander, ended up with a cracked hull. He's got a conscience so he doesn't want to sell it to someone knowing that the engine is bad, and if he does sell it with a bad engine he's going to take a serious hit on what he can sell it for.

Does anyone have a good engine ready to go, or have a reputable go-to builder?

Price seems reasonable, if not good, depending on what all is involved.
The 496 would be better of course, but may not be worth the extra money depending on what your son ‘s plans are for the boat.
Bostick Racing engines out of San Diego, is very reputable. But he might also be months out. I don’t know, just a recommendation to check out.

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Olds 455 is the preferred motor of choice for jet boters.

Faster than a paddle board.

 

[mash on it]

You wouldn't. Chevrolet didn't put 496's in HD trucks. I probably misinterpreted what you were saying. My statement was regarding if one were to source a 454, then it wouldn't matter what crank was in it if you were looking to build a 496.

496 IS the 8100 (8.1liter) in hd trucks.

Last year was 2005, I think.

Dan'l
Edit: at least til 2005.

 

[Jetboatjosh]

496 IS the 8100 (8.1liter) in hd trucks.

Last year was 2003, I think.

Dan'l

I have a 2005 2500hd and it has the 8.1

 

[SoCalDave]

Sanfords got one for him, even has over the transom exhaust.

 

[Chili Palmer]

Thanks for the replies, I forwarded this thread to him.

 

[was thatguy]

Sanfords got one for him, even has over the transom exhaust.

That’s a vdrive motor... headers are backwards.

 

[2Driver]

6.0 vortec all day in that. Mine was a marine power efi 6.0 in the 21 Ultra. great set up. Plenty of hole shot did 58-60 and great gas mileage

 

[Bigbore500r]

If he wants to step up to a 496 then he needs to find a wrecked HD with a BB. It will be 4 bolt main, 1 piece rear main, steel crank (I think), everything he wants, different heads for a carb set up (I don't know if his heads will bolt up) and he is set

That's a whole different 496....

 

[dirtslinger2]

Hit up @flatfast (Kenny) on here, he does some killer engine work, and is very reasonable.

 

[Your ad here]

A bored? and stroked 454 comes out to 496 ci. I bought a jet bote with a fresh built 496 from a 454 block. The crank broke the next day and had 9 hours on it. Something about not clearancing the block for the connecting rods and I think it was a scat crank? Also had chinese aluminum heads. Ended up putting in a stock 502 and swapping on the aluminum heads with new parts on them. Ran great, sounded great, and had great power for a N/A 502 with aluminum heads.

 

[jetboatperformance]

10 k , steel crank H beams balance 496 , Aluminum head options new HP HV oil pump 10 qt pan , Comp flat tappet Hydraulic

 

[3queens]

Rebuilt Hardin Marine Olds 455 - boat parts - by owner - marine sale

Rebuilt (0 hours) Hardin marine Olds 455. Comes with everything seen in pic. Asking 2500 obo. Rob

inlandempire.craigslist.org

Engine Marine 5.0 Liter - boat parts - by owner - marine sale

Mercury MerCruiser 5.0 Liter Thunderbolt V Ignition Engine Has only 65 hours Cash only No Exception !

inlandempire.craigslist.org

Inboard Marine Engines - boat parts - by dealer - marine sale

Atlantic Marine Store is an Engine Manufacturing company that has been building Marine engines since the early 70's, we sell everything from Small Block to Big Block, from Short Block to Complete...

inlandempire.craigslist.org

 

[4Waters]

That's a whole different 496....

I call BS GM doesn't change shit, that's a Ford thing

It won't work at all

 

[4Waters]

You wouldn't. Chevrolet didn't put 496's in HD trucks. I probably misinterpreted what you were saying. My statement was regarding if one were to source a 454, then it wouldn't matter what crank was in it if you were looking to build a 496.

They put the 8.1L, I thought that was a 496

 

[Bigbore500r]

They put the 8.1L, I thought that was a 496

It is, but its far different than a standard BBC that's "stroked" and built into a 496.

The 8.1 vortec (and 496 Mag, and 496 HO...) are a "hybrid" of sorts, utilizing the same bore as a 454 @ 4.250", but with a 4.370" stroke crank. That's the largest crank GM has ever installed in a gas engine. The cylinder heads are a cathedral port LS derivative. The motor uses hyperutechnic pistons and has a relatively thin ring-land, which isn't an issue when they are left stock but under boost they aren't very tolerant of detonation. There are forged pistons and a very limited selection of heads / upgrades available for these motors.

A traditional 496" BBC build based on standard BBC architecture uses a 4.310 bore (.060 over) and an aftermarket 4.250" stroke crank, whereas a std 454 is 4.00" stroke with a 4.250" bore.

Well Chuck....then you got your 502's.....
and that's a whole different ballgame Chuck.
502's just shit all over everything!

with a itty bitty 4.00" stroke

and a HUGE 4.470"factory bore

And know you know 496 vs 496 vs 502

 

[FreeBird236]

Maybe it's just the heads?

 

[Nikwho]

496 IS the 8100 (8.1liter) in hd trucks.

Last year was 2005, I think.

Dan'l
Edit: at least til 2005.

AHHH, I was thinking those were all 502's, but was thinking of the 8.2, apparently. My apologies!

Aren't those 8100 Vortec engines kind of a pain to find aftermarket heads and intakes for? Perhaps different cylinder spacing?? I had a line on one a while back to build for a hot rod, but was told that parts compatibility issues make it not worth while, or at least more expensive than just building a 496 from a 454 block.

ETA: this was all addressed above. I don't know anything about these. I honestly didn't know that they built a factory Chevrolet based 496, outside of the Mercruiser Marine engines. Learn something new every day! Sorry for opening my mouth, when I was out of my element. Anxious to learn more.

 

[mash on it]

A bored? and stroked 454 comes out to 496 ci. I bought a jet bote with a fresh built 496 from a 454 block. The crank broke the next day and had 9 hours on it. Something about not clearancing the block for the connecting rods and I think it was a scat crank? Also had chinese aluminum heads. Ended up putting in a stock 502 and swapping on the aluminum heads with new parts on them. Ran great, sounded great, and had great power for a N/A 502 with aluminum heads.

A .030" bore 454 block, with a 4.25" stroke is a 489 inch motor.
A .060 bore and 4.25 stroke is a 496.

A GM 496 (8100) has a 4.375 stroke.

That's all I got.

Dan'l

 

[guest hs]

@namba860 has some parts laying around. IMO 5-7k isn't out of line, but it all depends on long term goals.

That engine is all fixed and back together ready to go back in my boat.

 

[obnoxious001]

Price doesn't sound outa line, but I'd give Barry a call....

@obnoxious001

Sounds like what a local shop called me about yesterday actually.

 

[rivermobster]

Sounds like what a local shop called me about yesterday actually.

Well isn't that interesting!

 

[obnoxious001]

A bored? and stroked 454 comes out to 496 ci. I bought a jet bote with a fresh built 496 from a 454 block. The crank broke the next day and had 9 hours on it. Something about not clearancing the block for the connecting rods and I think it was a scat crank? Also had chinese aluminum heads. Ended up putting in a stock 502 and swapping on the aluminum heads with new parts on them. Ran great, sounded great, and had great power for a N/A 502 with aluminum heads.

Most aftermarket rods would not require the block be clearanced for a 4.25" stroke crank, with the exception of maybe some early 427 blocks. 454 blocks have small notches in them, don't usually see an issue there.

 

[SnoC653]

Jet boat engines take a little extra attention to detail to get the most out of them. They are up against the impeller HP curve. If they fall below the curve they simply stop accelerating and that is all you get. My 489 goes on the dyno next week to see what they can get. And I agree that the prices originally quoted sounded reasonable. What did the rebuild come in at, if we can ask? And what did you get for numbers?