There's so much you can do with a small block these days, there's the weight factor and I like the fact you can work on a small block alot easier in the engine compartment, no knuckle busting....jmo

 

BB

 

Blown Sb

 

What he said...

 

Yea sure (pics?) ... you must not be referring to chevy V8 ... aside from custom made blocks AND cranks; SBC bore spacing limits max bore to about 4.2" ... BBC bore spacing limits max bore to about 4.6".

 

Small block.

Some of the drag racers are starting to go with the big small blocks.
With a 406 and some 18 degree heads you can get 600+hp and have it weigh 200 lbs, or more, less than a big block. Thats a LOT of weight off the front end.

I have a mild 434 small block, 460 hp 500 ft/lbs. Plenty to get me moving.
I am running 11.90's in the 1320, and I can still put n2O on it if I want

 

By design a bigblock will always make more power than a smallblock given they got the same volume. Nothing like the sweet thunder of a bigblock.

 

Not quite true, plenty of small block heads that will flow in the 400+cfm range

 

Are you referring to 18 degree or less heads ?

 

Use of aluminum components on BB can drasticly close the wieght "gap" between BB and SB. The price difference between ZZ383 and ZZ454 is about $800. If you your car is set up for BB, its a no brainer, go BB. If not, you'll have to make the choice. The weight difference between BB and SB was recently posted, and suprisingly, it wasnt as much as you would think.

 

I don't want to get into a p ssing match here, just directly answering your statement which roughly said, for the same volume a big block will make more power than a small block. Yes I am referring to 18 or less deg heads

 

Yeah, but how many smallblock heads can flow 500CFM like the Big Duke/Big Cheif do? For absolute max power and torque and as long as we're comparing apples to apples, big blocks rule. You can't compare some 12 degree SB2 head against conventional big blockheads, make it an apples to apples comparison and compare 12 degree heads against each other.
There may be a lot of drag racers going to small blocks, but there are just as many taking advantage of what you can do with a big block - 632's are selling like 555's did a few years ago. Torque is a function of size of piston top for the expanding gasses to act on, cylinder head efficiency, and the length of the stroke; displacement is derived from those two factors. That's why the "no substitute for cubic inches" expression is still so valid today.
Stroke and bore your smallblock as big as you want, add spray and a blower if you want. I'll do the same to my big block and we'll see who wins that horsepower war.

 

wont fit, air clearner issues also the block is different than the old big blocks Dont be shy about going with a sm block if it already has one I been beaten by many a sm block specilly the ls1 and 2s

 

BB all the way, one of my future planned mods...

Also one thing to note, most car nuts go after HP, me, I'm all about torque and especially at low rpms. Why stress out a SB to make the same HP tq at 6000rpm as a BB does at say 2500 rpm. RPMs kill motors, less rpm less wear. Also the weight difference is somewhat negligeble, sure a SB will weigh in less, but if it has to take time to spin up to it's power range which a BB is at just after tipping the throttle the weight advantage is offset in terms of streetable performance.

To each his own, enjoy

 

The key to his statement and the one I replied to was "same volume" are you going to make a alot more HP with a big block 454ci over a small block 454ci ? Think again

 

I was thinking of the Mark IV vs Gen I smallblocks

 

I don't agree, a cubic inch is a cubic inch. But in ultimate power handling. The aftermarket small blocks are limited to @2000 hp. Where aftermarket big blocks are 3-4 times that amount in top fuel dragsters.

 

Yes I agree with you the bigger motors have always made more power than the small blocks, these days though with the bigger inch small block the advantange has gone away untill you get into cubic inches where it is impossible to go with a small block

 

How much power is enough?


As everyone has a different goal for their vette, it's not a simple answer.

I have been expending lots of mental energy trying to decide whether to go for a stroked small block or go for a big block transplant in my 68 vert.

Any real passionate petrol head would drool over a stroked big block of 540+ cubic inches under the hood. The thought of over 600 lbft of torque available off idle, and upwards of 600 HP at the rear wheels sounds like tarmac heaven.

But realistically, where can you use that sort of performance other than on the race track?
And the cost of upgrading from a small block to a big block installation spirals disproportionately to the performance vs dollar value.

Realistically, I don't think I need much more than 400~450 horsepower for a street car. If I can get around 400 ftlb of torque driving my rear wheels, I'll have more than enough issues trying to keep the car in a straight line.
If the vert can run mid to high 12's with this configuration, I'd be ecstatic.

So after much deliberation and neuron crunching, I am leaning heavily towards a mild 383 performance small block.
It will have the performance of a factory big block, yet be easier and less costly to install and maintain.

PS: If money was not an issue, then an alloy 540ci would be my choice

 

seems to me a 427 sbc shortblock from ohio crankshaft with afr or brodix fully ported heads (the big ones) would be cheapest and achieve 550 hp with a stout but not radical hydraulic roller. 434 and 454 sizes are only 2-300 bucks more if memory serves me.