What kind of things do I need to consider when building high hp bracket engine. I am shooting for around 750hp. Should I build as I would a race car engine? What differences are there in doing a boat engine? Should I use block fill? How about alum heads? Oiling system? Tolerences? Any advice would be great as I would like to do it wright the first time. I am planning on using aftermarket rods, heads, and a stroker crank. I have a 472" hemi we use to use in a 3000lb super gas racer, should I just drop it in and go or what? My buddy keeps telling me to build a blower engine for the hp and dependibility.
Thanks!!!!!
Basing the motor on a Chevy will make it easier and cheaper, but if you already have a hemi sitting around, go for it. I agree that a blower is tha way to go, or naturally aspirated on methanol. Boats like torque, so go for lots of cubes, unless your running a 2-speed Lenco or something. What kind of hull are you runnning?
Yeah I am sort of stuck with the mopars. Its going in a 18' bubble deck.
Chevy, gezz, are you kidding? With a name like VoodooCanoe426, do you think you are going to convert the guy to buy a Chevy based on price? Get a better job so you can afford more expensive parts. HaHa. Everytime I hear how much cheaper it is to build a Chevy, I just laugh. A 30,000 peice of fiberglass and all you people cry about is how much cheaper a Chevy is to build. You are killing me over here.
HaHa,
More on this when I get off work,
Brian
Voodoo canoe, yes you would build the motot like you would build a super gas motot except camshaft if it is a jet you would run a little closer lobe center,and alot of carburation. weight makes a big differance in a jetboat alum heads are the way to go. 750hp in a v bottom will get you about 11 second boat, put 800 hp and buy the cruasader tunnel i told you about and you will probably run 10 second bracket. Jim
That's as funny as "the best gas mileage possible" with Hi-rise running dual Double pumpers...
The boat it will be going in is a 18' v-drive.
I ran a 426 Hemi in a Biesemeyer v-drive in the 70s. In fact I still have the bellhousing and aluminum flywheel for it. (158 tooth). Here is some of the things I found. First, you will find yourself making a lot of you own parts. The front of the engine mount comes to mind. If you're going to run an oil cooler, it will have to be stringer mounted and there will be lots of plumbing to do. Speaking of oiling, a Hemi in a boat really needs to have a Side Oiling kit (thru the cross bolts) installed to keep the Mains oiled. As far as camshafts, the secret to a naturally aspirated Hemi is running close center lines. Most after market cams come 108 degrees. The reason is that if the center is too close the valves run into each other if the lift is too high. If you can get away with a cam with 105 degree lobe centers, the motor will come alive. Also, never, and I mean never, run more than 35 degrees of lead in the ignition timing.
I make parts to put a wedge in a boat. The right motor mount(the "flat" side) would be a little harder to make but not impossible. CNC machined
plates to put AN fittings in the water ports, Aluminum driveshaft yokes, and other parts.
Shameless spam.
Brian
Thanks for the input. I think I am just going to freshen up my engine and drop it in.
Brian I already have the plates and a rail system for the stringers.
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