wstultz

If you were to build small blocks, with anywhere from 400 to 500 hp and had to run on 93 octane, What would you put in them?

dean51267

not an engine builder, but first I would put in a lot of money, getting 450 hp from a small block will be expensive....

That said, a big cam, full roller, Merlin Heads, good exhaust, good intake, balanced nad blue printed, 830cfm or better carb, 10.5:1 or so, maybe a small blower is in order (lower compression of course). You are going to have to turn a LOT of RPM's meaning a very good balance job and lots of fuel, meaning file to fit rings, forged pistons, steel crank, big rods, good rod bolts, possibly a stroker motor????

My guess would be if you want reliability you are going to have to go to a blower,

Griff

Getting 450hp out of a SBC is not difficult. Just need to supercharge it and use reliable internals and spin it to 5800-6000rpms. I did it with a 355 sbc, stock .202 heads, a flat tappet cam, and about 7# of boost from a B&M 174 SC. This was in a car and it was dynoed at 440hp.

What boat should it go in????

292 Fastech
28 Donzi
28 Pantera

wstultz

30 foot Sutphen. It has arnesons so it no problem turning the rpm's. I have small blocks in it now....unsupercharged....turning about 415 hp. I don't like the set up and was looking to change. The engines it came with were sbc making about 550 but they were 12:1 and required 110 octane.

BillK

If you really want to stay with "small" blocks, I would go with a pair of bigger cu in ones. Maybe in the 420 cu in range. They would make an easy 450 hp on 93. Aftermarket blocks and heads, the best internals you can get, roller cams etc.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

SB

iTrader: (1)

I'm totally with BillK here, as i think most will.

400hp is no sweat - easy for 383. A 350 can do it but would need some good compression that will be borderline for pump gas.

500hp is out for pump gas with 350. A 383 can do it, but would be better with some gas 'mix' since compression will be near 10.5:1.

420 will do it on pump gas. This is about the farthest you'd want to 'take out' a Chevy 400cid block.

427 / 434 really requires a new / better aftermarket block. This will make things a little more expensive, but not really bad. 500hp should be a breaze....and thus of course pretty reliable.

Current cyl head technology is unbelievable, so add these with some good cid's and you'll have some good motors.

As far as parts for the build up a minimum of good forged Eagle crank, rods, and forged pistons. Crower, Callies, Lunati, etc,etc can be used as upgrades.

Cyl heads - well, a very loose rule is that you'll need near 300cfm intake ports to handle 500hp. This takes many heads out the 'possibilities' but it also leaves many in.