Reply With QuoteHow much Nitro you runnin??
Hey, I've got a choice to build a 468 (454 + 60 over) Big Block Chevy, or a 441 (427 + 60 over) Big block chevy for this 68 hondo, probably just a lake cruise/hotrod with a tunnel ram, dual carbs, headers. ????Short or long stroke engine??(gears are casale 15-18%), and what type of prop should I buy? What I'm really curious about is, has anyone run a aluminum flywheel in a v drive and what effect did it have vs. a heavy steel flywheel. We ran a aluminum fly in a radical 396 bbc jet boat and boat ran significantly low rpm, but got there immediately out of the hole. Any ideas????
Daddy B
How much Nitro you runnin??
Since it is a lake boat go for the longer stroke and cubic inch 468. The flywheel deal is not a big issue. Use a flexplate and gain the lighter weight for less money than an aluminum flywheel.
Prop wise..try to borrow someones. They are all different. Something like a 11 1/2 x 15, 10 3/4 x 16, maybe even an 11 1/4 x16. Two blade.
Originally posted by Fiat48
Since it is a lake boat go for the longer stroke and cubic inch 468. The flywheel deal is not a big issue. Use a flexplate and gain the lighter weight for less money than an aluminum flywheel.
Prop wise..try to borrow someones. They are all different. Something like a 11 1/2 x 15, 10 3/4 x 16, maybe even an 11 1/4 x16. Two blade.
Thanks Fiat48, that is a beautiful boat you have, wow! Got any more pictures.
I figured that bigger is probably better in this case, approximately the same cost. However, I have a new gm 427 forged crank I was trying to find a place for. The vintage friends are leaning for the 427 bbc + 60 over but they don't know flat bottoms. I value your opinions and experience. Yes, I was wondering about a flexplate, seems like it would accelerate faster. My experience is with Jet boats, and I currently have a 468 bbc in the family boat but cubic inches and torque, and heavy flywheel is important in the jet boat. Anyway I was thinking about building something slightly different.... I do have a 671 GM blower that needs rebuilding..... Hmmmm
Thanks Daddy B
I agree w/ Fiat48. We have a Sanger flattie w/ a 468 BBC. We use a flex plate, lot less weight, more responsive. We run pump gas 10.5-1 w/ aluminum Merlin heads 2 660's, a Comp Cam solid lifter deal w/ .250 long Crower rods. 18% gears and a 11 1/2 x 15 prop. Runs all day will pull close to 7000 rpm. Flattens around 6800-6900.
I'm gonna play devil's advocate here and vote for the 441" BBC. I like a shorter stroke/long rod dealio, it broadens the torque curve and is generally a bit easier on parts. Yeah, I know there ain't no replacement for displacement but I like uncommon combos. Besides, With a lake boat you probablly would not be able to tell the difference between the two anyway.
Originally posted by 058
I'm gonna play devil's advocate here and vote for the 441" BBC. I like a shorter stroke/long rod dealio, it broadens the torque curve and is generally a bit easier on parts. Yeah, I know there ain't no replacement for displacement but I like uncommon combos. Besides, With a lake boat you probablly would not be able to tell the difference between the two anyway.
Thanks for the feed back, ya'll.
The 427 crank is forged, the 454 is cast, pistons can be forged, soooooooo ??? The rods are standard length so it's not a long rod motor but, I guess it should really be called a 439 bbc, but the real benefit I see is the ability to run a little more high rpm camshaft with a nasty lope, and with a flex plate I think the thing would rap quick and maybe idle a little more radical with less rotating mass. I still need to keep compression @ 9.5 with steel oval port heads. It is a 68 Hondo which weighs a bit, but I'm honestly more into sound, and looks, on a budget. I really just want the thing to sound nasty, I think it will be fast enough regardless being used to jet boats only. Block is at Power Performance awaiting for my decision for build. Nothing is cheap these days, wow!! 600.00 plus just for machine work.
Thanks again, Daddy B
Originally posted by daddy b
Hey, I've got a choice to build a 468 (454 + 60 over) Big Block Chevy, (gears are casale 15-18%), and what type of prop should I buy?
Daddy B
I would go with the 468 and 18 gears with a 11.5 x 15 two blade Prop. This will make a kick ass river racer!! My $0.02
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