How much boost w cast crank?

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How much boost w cast crank?

Post  schmiddy on December 20th 2012, 12:00 am

Rebuilt my boats 514 last summer:

514 bored .030, still has the cast stroker crank, forged pistons, rods, roller valve train, non-ported BT alum heads, 1050 dom.....dyno'd 660hp w a mild cam.

I still have the cooled Banks TT setup and mulling around the idea of swapping out the cam and bolting on my tiny turbos! I know I shoulda just bucked up for the forged crank, but I thought 600+ HP would be plenty.....WRONG!!!!

Am I just asking for trouble even while running just 4-6 lbs. boost?

Opinions?


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Re: How much boost w cast crank?

Post  IDT-572 on December 20th 2012, 11:25 am

It wouldn't bother me at all...............

But you need to ask yourself and be honest , can you keep your hands off the wast gate and leave it at 6 lb's Laughing
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Re: How much boost w cast crank?

Post  dfree383 on December 20th 2012, 11:45 am

I wouldn't be afraid of using a factory 460 crank at 700-800 hp at all, I've done it quite often. Problem comes in when you start putting some bigger 4.3 and 4.5 stuff and loose the journal overlap, them the forged stuff comes into play.


Last edited by dfree383 on December 20th 2012, 11:48 am; edited 1 time in total
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Re: How much boost w cast crank?

Post  IDT-572 on December 20th 2012, 11:47 am

Wouldn't
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Re: How much boost w cast crank?

Post  dfree383 on December 20th 2012, 11:49 am

IDT-572 wrote:Wouldn't

Caught it...... king
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Re: How much boost w cast crank?

Post  Paul Kane on December 20th 2012, 1:00 pm

schmiddy wrote:Rebuilt my boats 514 last summer:

514 bored .030, still has the cast stroker crank, forged pistons, rods, roller valve train, non-ported BT alum heads, 1050 dom.....dyno'd 660hp w a mild cam.

I still have the cooled Banks TT setup and mulling around the idea of swapping out the cam and bolting on my tiny turbos! I know I shoulda just bucked up for the forged crank, but I thought 600+ HP would be plenty.....WRONG!!!!

Am I just asking for trouble even while running just 4-6 lbs. boost?

Opinions?

I know a guy with a 512 CI jet boat that uses a 4.14" OEM offset stroked crankshaft and his engine dyno'd at more than 800 hp. Then, he adds a 200 hp shot of nitrous oxide (estimated ~1000 hp total). Been running it that way on the water for years, no problems.

In regards to the Rayjay turbos with the water-jacketed exhaust housings: don't spool those little turbos up too far with the 514 stroker, be sure to limit boost. The turbos are good for their intended application; guys that go deep in the double-digit boost numbers with them spin them so high that they can fly apart. The good news is that they have a built-in bypass (aka "Okie waste gates") which ought to prevent you from over-spinning them. But if you plug the bypass ports in the housings then all bets are off.
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Re: How much boost w cast crank?

Post  schmiddy on December 21st 2012, 12:43 am

Thanks for the added assurance. I may just bolt everything on and go.....

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Re: How much boost w cast crank?

Post  Paul Kane on December 21st 2012, 12:48 am

schmiddy wrote:Thanks for the added assurance. I may just bolt everything on and go.....
What is the engine's current compression ratio?
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Re: How much boost w cast crank?

Post  schmiddy on December 21st 2012, 3:17 am

9.8:1

can't remember what my cam specs are.....but it's nothing radical

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