Required internals for 6 psi?
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Required internals for 6 psi?
I'm piecing together some 454/468 motors with forged pistons. I read somewhere that for 90/100 hp per piston, you can stick with stock internals(??). Forged pistons are a no brainer (probably set these up with 0.005" clearance)...went through the hyper-u-cracked it experience on a naturally aspirated motor...wasn't pretty. Will shot peened stock rods and a standard cast crank work with 6 psi (intercooled) efi boost? I plan to use wide band O2 sensors and EGTs so I have a good grasp on what's burning inside. Also, what about the standard mercruiser coupler...and Bravo ones hold up to 600 hp...continuous? Obviously, a forged crank is the way to go, but is it necessary with mild boost and just over 5000 RPM?
The boat is primarily just a cruiser with the periodic grudge race for a few minutes. No poker runs for me...can't afford the engine builds let alone, the fuel costs! I thought twin 400 hp motors would do...the addition continues with turbos!
The boat is primarily just a cruiser with the periodic grudge race for a few minutes. No poker runs for me...can't afford the engine builds let alone, the fuel costs! I thought twin 400 hp motors would do...the addition continues with turbos!
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The stock rods, as long as they have 7/16 bolts, not 3/8, will work just fine. I would in put a set of ARP bolts. The rods must then be resized. However, I would not even try with a cast crank. You can pick up a used forged crank pretty cheap. You can also get a new Scat for about $600-$700. The coupler and drive should be fine as long as you don't drag race it. Hard acceleration will kill a bravo behind a blower motor every time. Eddie
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Thanks Eddie.
Absolutely no plans to drag race the boat...being weighted down with A/C, gen set, TV....bunch of heavy stuff with normally 10 people on the boat. Just looking to have a decent top end in the rare situation when a stock weisenheimer pulls up to me. Besides, these center consoles are getting faster down here in South Florida and that is embarrassing if a bunch of fishing poles blast by you. Hasn't happened yet, but I won't leave it to chance!!
Absolutely no plans to drag race the boat...being weighted down with A/C, gen set, TV....bunch of heavy stuff with normally 10 people on the boat. Just looking to have a decent top end in the rare situation when a stock weisenheimer pulls up to me. Besides, these center consoles are getting faster down here in South Florida and that is embarrassing if a bunch of fishing poles blast by you. Hasn't happened yet, but I won't leave it to chance!!
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I guess I should rephrase that. Not drag racing, but hard acceleration will kill the drive and coupler. Being past by a cc is almost as bad as being past by a deck boat.
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But, I don't go by near 95 MPH!! The jelly would splatter all over the inside of the boat!