rtchaney

A chevy 350 has a 4" bore and a 3.48" stroke, i think that a 3.75 in crank and a 4.030" bore makes a 383. What makes a 400, or even cooler, a 427 sb? Also, is it possable to put a 4" crank into a 350? I'm just looking for good combonations.
Thanks.

Apeiron

A 400 is a 4.125" bore with a 3.75" stroke.
A 427 is a 4.125" bore with a 4.00" stroke.

A 350 block with a 4" stroke is a 402.

Any combination that involves using a non-stock stroke will usually require some clearancing of the block. The longer the stroke, the more modification is generally necessary.

rtchaney

What type of mod is req. for a 350 w/ a 3.75" srtroke? Does that mod differ for the 350 with a 4" stroke?

Sonix

iTrader: (1)

Look up "383 mods". Capscrew rods, small base circle cam, clearancing a bit on the block, etc. Some/all of these are needed. Kinda depends on the case.

4" stroke is not really possible on a stock block, as far as I know.

TheScaryOne

iTrader: (3)

I saw this, and want to try this in my car, but everyone says the max bore for a L98 is .060 over. This goes to bore 4.155, and has a 3.875" stroke. They say they used a stock block. *shrugs*

420 Cubic Inches: L98 motor

Lingenfelter 420, from his book- Modifying Small Block Chevy Engines.

3.875" stroke Callies crank

Oliver 5.875" rods

11: 1 compression, custom forged pistons.

Used a Bowtie engine block

Comp Cams mechanical roller cam: 236/244 @ .050, .549/.549 lift, 110 deg lobe sep, 1.5 roller rocker arms by Comp Cams.

Lingenfelter ported AFR 190 aluminum heads

SuperRam intake, base, and 58mm throttle body, controlled by DFI using 36lb/hr injectors.

543ft/lb of torque@4500RPM 525hp@5500 RPM
417ft/lb@2000RPM

As you can see from the numbers above, the motor is a torque monster. The combination of the large displacement, smallish heads, high lift roller cam, and the intake system make big block torque in a small block package. This motor computes out to a 113% efficiency at the HP peak, which is an indication of how well matched this combo is.

yupitsdadsbird

4.155 bore would be a 400 .030 over

a 30 over 400 with a 4 stroke is a 454 right?

zipfast

iTrader: (2)

BORE X BORE X STROKE X 6.2821
4.155 X 4.155 X 4.0 X 6.2821 = 433.817 or 434

TheScaryOne

iTrader: (3)

But it's using a 3.875 stroke. Not a four.
4.155*4.155*4.00*6.282=420.260

But it's listed as a L98 engine mod. I might just have to buy the book and find out. :/

Edit: Ignore my smart assed math. I completely didn't notice the question above.

yupitsdadsbird

then I don't enen wanna know how they make a 454 sb, lol

Apeiron

A small block 454 is a 4.125" bore aftermarket block with a 4" stroke.