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Mesa AZ
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got a little problem? a buddy of mine blew up his 454 in his jet ,a spun bearings , crank junk. he is debating building a 502 but dosent want to have to buy everything . his pistons ,heads ,rods, cam are all still good from the 454 . Is it worth buying all the parts for the 502 or would it be more benificial to stay with the 454 . some questions are what parts will not fit from the 454 to the 502 . the 454 was 11:1 comp. what will be the hrse power gains . just looking for solid opinions and he isnt building a jet dragboat 60 to 65 mph boat.
 

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He could stroke the 454 to 496. Does he already have a 502 block? I think the head interchanging is somewhat iffy, water jacket issues. May be some one else will chime in.
 

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B.A.M aka "Black Azz Mike
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B.A.M aka "Black Azz Mike
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Hit it where you fit it
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got a little problem? a buddy of mine blew up his 454 in his jet ,a spun bearings , crank junk. he is debating building a 502 but dosent want to have to buy everything . his pistons ,heads ,rods, cam are all still good from the 454 . Is it worth buying all the parts for the 502 or would it be more benificial to stay with the 454 . some questions are what parts will not fit from the 454 to the 502 . the 454 was 11:1 comp. what will be the hrse power gains . just looking for solid opinions and he isnt building a jet dragboat 60 to 65 mph boat.


I have a Gen IV 496 (4,310" x 4.25" ) and it runs hard but........ a 502 with the exact heads , cam ect... will run slightly harder. The larger bore & short stroke is the hot set up for unshrouding your valves and improving overall air flow as well as a decreased rod angle ect..( less stroke can fit a longer rod in a standard deck block)...

Drag boat or not if a 502 is easy to get rolling I would lean towards a 502. If you have a lot of 454 goods laying around it may make more sense to go that route instead $$$$$.

Big bore + short stroke IMO is the hot set up for a jet boat, and maybe next time I will figure that out prior to having my motor built..:D
 

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jetboataholic
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If I had the money, I would go with the 502. But, if money is an issue (as it usually is) I would go with the 454, especially if you have most of the parts for the 454. Try sticking this thing in the "On the Dyno" section as well.

My dream engine for my boat is a 502, but that is a long way off in the distance.:(

Good Luck!:)hand
 

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If I had the money, I would go with the 502. But, if money is an issue (as it usually is) I would go with the 454, especially if you have most of the parts for the 454. Try sticking this thing in the "On the Dyno" section as well.

My dream engine for my boat is a 502, but that is a long way off in the distance.:(

Good Luck!:)hand
If it is a dream why stop at 502. there are bigger motors.

Cy
 

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He could stroke the 454 to 496. Does he already have a 502 block? I think the head interchanging is somewhat iffy, water jacket issues. May be some one else will chime in.
i have a gen 5 block with gen 4 heads.never had a problem as long as you use the right head gasket.the oil pan was to deep,but milodon make a 10 quart pan for around 300.dooley makes one to.
 

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Where Are You Located?? I Have A Gen 4 Crank Just Polished I Picked Up Tuesday That I Was Gonna Use But I Got A Deal On A Steel Crank So I Dont Need It Anymore. Mains Are At 30 And The Rods Are At 20. I Have Clevlite Bearings In Boxes Ready To Go. $300
 

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E-7 Sheepdog (ret)
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Sounds like a decent deal there Klinger.
 

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"It's HONDO, honey"
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stick with the 454, save money........................ and when it blow invest the saved money in 608 :D. 454 reuse what hes got go for reliability and cost effect. "Speeds money, how fast you want to go" :)hand
 

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21 Daytona
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5,291 Posts
got a little problem? a buddy of mine blew up his 454 in his jet ,a spun bearings , crank junk. he is debating building a 502 but dosent want to have to buy everything . his pistons ,heads ,rods, cam are all still good from the 454 . Is it worth buying all the parts for the 502 or would it be more benificial to stay with the 454 . some questions are what parts will not fit from the 454 to the 502 . the 454 was 11:1 comp. what will be the hrse power gains . just looking for solid opinions and he isnt building a jet dragboat 60 to 65 mph boat.
If he wants a complete GEN 6 HO 502 450HP Marine power worth the $$ send me a PM.
 

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502 or 454

I have a Gen VI Steel Crank listed here in Parts Spam. Magnaflux was good and it was just turned .010/.010. Sounds like you might not need the other parts listed. Let me know. And basically the difference (depending on the Generation of your engine) between a 454 and 502 is bore. 502 is a 4.00 inch stroke and a 4.467 inch bore, 454 is a 4.00 inch stroke and a 4.250 inch bore. Hope this helps. What Gen is your BBC? 1 or 2 piece rear main seal?
 

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forget the engine and get some paddles...then buy lots of beer and enjoy this sh*& is crazy 5.29 for diesel 4.50 for premium..just my .02 I bought a new boat and cant sell my jet boat or get my new boat to the lake WTF...I think I quit...better yet buy the 87 Bahner in the spam section and pull the 1 season old 496 out of it and sell the rest, maybe make some money on the deal too it runs 68 mph in my 21 so in a smaller boat who knows definitely faster...
 

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jetboataholic
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If it is a dream why stop at 502. there are bigger motors.

Cy
I know!:rolleyes:

My dreams are realistic!!!:D

But, I don't think that fuel is going to get any cheaper, any time soon. And the 502 would suck down enough fuel as it is, why suck down more, when the 502 would be plenty powerful enough.:)sphss:)bulb:D

I never said it would be a stock 502, either.;) Maybe some nitrous, and some goodies on the inside and outside.:D

Plus, I wouldn't be drag racing it. I just want to be able to run 90 mph or so if I want to.:D (Of course with the right pump setup too.) If I had the money I would just take a 500 mile drive to MO and have Duane at HTP setup my boat right, and really make it rock!:)devil

:)hand
 

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"It's HONDO, honey"
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4.500 bore and a 4.250 stroke, 6.385 rods and in standered bore punch one of dem chevy's out to a 555 cid. hell ya :)devil
 
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