smiklos@sunprint

iTrader: (1)

Guys
The amount of R&D sbc to bbc is very easy to see. The trickle down effect right now is about 450 hp for a cheap old school Ed Cole sbc. Bravo drives last longer without torque boats like torque but also need rpm to work.

Small singles sbc can work small twins sbc can work. Anything big that's a Vee needs a bbc.
Steve

Uncle Dave

"blowing away guys with BBCs' - That was my personal motivation behind building a nasty small block. This and handing it to a few outboards guys I know. The old "hot rodder" doing more with less thing.
A small block with a carb- anyone can deal with it - simple and easy.

Ive put so many Big Blocks on the trailer I've lost count, but I spent more money to do this than just building a big block for the job to go X fast.



Not much but it certainly wasnt cheaper. - I got what I paid for and am not complaining. My mills been putting out 500+ beans for about decade pushing about an 1800lb boat its pretty thrilling. Getting tired but still quite satisfying.

To fireboat pilots point -True more is almost always better than less, but Im not sure it is all about cubic inches entirely. From all my money and time expenditures I think its about cylinder heads. A 454 small block wont run as well as a 454 BB unless you dump huge money into the heads. Without blowers and turbos its all about the heads.

Uncle Dave

2112

+1
With a caveat.

I think that if you aren't necessarily going for maximum performance, and your hull would benefit with the weight savings, a small block is an economical alternative.

I think that was the jist of the original question.

.

twistedvelocity

another thing i've always wondered is why don't you see crazy HP number boat engines like in dragsters

twistedvelocity

I gotta give some credit to a 350sb when it can produce 700-800hp NA and run close to 200mph for 500 miles

donnawanna

I have no doubt that I can make twin sbc's with aluminum heads and all forged bottom ends produce 550 hp each at under 6000 rpm and over 500 ft# torq. at 5000 rpm. I would also save close to 450 pounds. that should make the boat I have run in the mid to upper 70's.
The big thing I am worried about is the size and weight of the components like the rods and crank. Will they take in and out of the water on rough days like it always is on lake erie? The less torq. might be easy on the drives but whats going to give? or will the motors take it?
I have priced it out both ways. and the sbc prices are less when compairing high quality parts. when trying to build hp numbers you can cheepen the quality of the bbc parts and still produce the hp numbers thats where the savings is. The other thing to worrie about is if I don't like the sbc's everything has to be changed to go back to bbc's where with the big blocks I can just up grade the motors with out changing exhaust, intakes , distributors,cooling' and on
The bottom line for me it's too much money and time to risk to try the sbc's.
Great debate

endeavour32

iTrader: (4)

You're choosing the right engines.... I really wanted to build a high HP SB for my Formula 242, just to prove a point it could be done. But I need torque, and the SB is at a serious disadvantage. Instead I'm building a high reving BBC 440. Bob Mandara is designing the cam and seems really excited about this project, he said this engine is going to have serious midrage pull/excelleration. I like it because it's different. Everyone is building stroked engines now, where I'm going the opposite route. Either way good luck with your project.

spectras only

All my boats before the current one had big blocks.
One of them was a jet [ constant high RPM's ] with a 429 Ford I've rebuilt in 1989 . My friend owns the boat with around 2000 hrs on it, still kicking.


The 6.2 engine in my boat is a pretty good one IMHO. Crane billet roller cam and steel crankshaft stock from the factory.
The only weak part is [ only if one wants to supercharge it ] the hypereutectic pistons .Nothing wrong with those pistons though , counting over 140K miles on them in my 1996 Mustang GT .It doesn't burn oil , compression still great and oil pressure steady as when it was new. The rev limiter on the 6.2 is set to 5350 ,turning 5000 with tuned 26P B1 props .I ran poker runs at WOT for extended times , no problems so far. Only problem I had with is the IAC valve, no biggie. If I develop more problem with electronics , it's an easy fix to convert to carb , so will see how many hours I'll get out of this package. My boat weighs in at 8350 lbs on the trailer [- 1600 lbs for the trailer]
Ran 76 on the dash Gaffrig GPS ,24* deadrise with a V shaped Delta pad.Pretty happy with small block power so far.

Raylar

Beautiful Spectra and the SBC's are doing a fine job in that boat in your use. I suspect the other truth is that a pair of 496 or 502 BBC's with aluminum heads in front of those drives in that boat at 500HP each mild spec would push that boat 85-90mph with 30P props and use the same amount of fuel at cruise! thats why I still support
There Ain't No Replacement for Displacement" in a moderate size to larger performance boat!

Best Regards,
Ray @ Raylar

4mulafastech

I have twin 6.2's in my 292 Formula. 189 hours and only one IAC problem like you. Looks like they must have got a bad batch.

Mine runs right at 70 mph. It's a bit heavier than yours at 7500 lbs. It's a twin stepped hull with a 24° deadrise.

Big blocks in either one of our boats would be A$$ heavy and we would lose rough water handling.