traviss

Dyno.. Find a crank thats forged 4130-4340 that fits your budget and you wil be happy. You just don't skimp on major parts like cranks. The marine enviroment is the hardest on engines, with the load, rpms, temps, ect. My idea is to always over build so nothing will break. My experiance with my small block crank, I have run my forged 4340 eagle crank for a total of 125 hrs, and most of the time it is running hard. I am going to be running it in my 3rd motor come spring, I have not even had to polish the crank yet, it was gorgeous and undamaged. If you use the clevite "h" series bearing you should have no problem withe fillets on the crank, I know alot of people on here have had a bad experiance with eagles.. But for me.. I love my eagle, perfect foundation for my 570+ hp small block

just my .02

AWELSH

I had my Mag496 reworked by Tyler Crockett. Dyno sheet shows 550hp at 5400rpm. Haven't used it much since being reworked. I think Tyler suggested WOT rpm should be 5100 to 5200 rpm. I have some minor idle issues which I need to work out with Tyler. He won't be back in the shop until after the new year, I'll speak with him then.

Whiteknuckle

The last dyno pull on my stock cast crank and rods was 440HP. I twist it to 5200 RPM often. These are stock 330 HP components. We did align bore the block, use ARP rod bolts and re-balanced the rotating assembly. I would not hesitate to upgrade to 500 HP on the crank.
What is wrong with the GM forged crank? I don't hear anyone using that, they just talk about aftermarket stuff.

mcollinstn

Nothing wrong with the GM forged crank.
It just doesn't have the big fillets you'll find on an aftermarket crank.

The GM forging will hold up nicely in a 6000rpm 700 horse marine motor (I'd use a Fluidampr on it, though - but then again, I'd use one regardless).

I would stick with the GM forged crank unless I was going bigger than a 509. And I wouldn't bother going bigger unless I had a talldeck.

Crazyhorse

Nuts to the gas engines. I think we oughta use electric motors and batteries with a deck full of solar panels.

Crazyhorse

Oh crap, the Percodan is wearing off.

dyno

Dave go back to bed!!! Step away from the perscripition drugs!!

Crazyhorse

No way, bub! My only regret is that I have to waste them on pain.

dyno

I'm going to put you on the 12 slap program!!!an intervention is in your near future!!!LOL

Crazyhorse

yeah, sooner or later (I'm hoping later) our employer is going to intervene and want me to actually perform physical labor again.