For example, a big block 427 and a small block 427. What's the difference. Is the SB 427 simply a stroker that was built up from a smaller block(crankshaft, bored out). Are there any major power differences?

 

The physical size is the most obvious. An SBC 427 is a 4.06" bore with a 4.125" stroke, I am not sure what a BBC's bore/stroke is though.

 

the BBC will make more power than the SBC due to the valve size's, runner's, intake, exhaust, etc. the main difference is dimensions and weight.

later,
Dave

 

427bbc-4.250 in. bore x 3.76 in. stroke

 

BBC w/ the smaller stroke will rev a lot higher and the bigger bore is also better when spraying. I've read that the bigger the bore, the more nitrous-friendly the motor will be.

 

It will greatly depend on what particular engine combo you are talking about. A 427 SBC can be made about 20 different ways depending on the block used. A stock 427 bbc will make far less hp the average 427 sbc. Reason being heads. Today there are sbc heads that flow more air then any stock bbc head. It all depends on the build. Most 427" sbc have an aftermarket block. Take prayhrd's 427 for instance. It has a 9.3" deck to allow a long rod, yet has a 4" stroke and a wider 4.125" bore. One major benifit to a properly built sbc is not only the light weight of the motor, but the super light weight of the rotating assembly. On the other hand, if you put a set of 500 cfm Alan Johnson heads on a 427 bbc, you'd never be able to match that power with a 427 SBC. A SBC is limited to a head flow of about 420 cfm, max. All in all, cubes are cubes. The main power difference is in the heads. So use that as your seperation factor when deciding power potential of each motor.

 

what the........how's he know that?!?!?!

 

Agreed on the cubes comment. I've always gone with small blocks for 3 reasons:

1-lighter (most BBC vs SBC are about 150-200 lbs heavier, not accounting for aluminum blocks and such)
2-it's what I'm more familiar with
3-cheaper in most cases (flame away on this, but in MOST cases, not all)

If starting from scratch, if you want to make big power, most suggest BBC power. But to each his/her own!

Derek

 

SBC for life!! not only is it smaller and capable of the same cubes as a lot of bbc's but they are a lot easier to put in most cars. its only a matter of time before there are 500cid and bigger small blocks out there

 

There already are. Years ago I saw an article and basically it was trying to see how big a small block could go. An OLDs DRCE or I think Rocket block could make a 580 something cubic inch small block.

 

580?? How. Max, paper thin bore on a rocket block would be about 4.250". You could maybe push a 4.3875" stroke with major block clearancing. I Know for an all motor setup you can do a 4.25" bore & 4.25" stroke. I think that is a 482", And that is stretching the limits. What would the bore & stroke be. If you had a block with a spread bore centerline, you could maybe do that, but otherwise I do not see how it could be done.

 

The bbc will make more power but it is more difficult to fit into a late model car.

 

Big block chevys make massive low end torque. I had a '63 1-ton 4x4 running a mild built ls5 454 that weighed 6000lb's and I could roast all four 38.5 gumbo monster mudders. I twisted many a drive line and broke many a lakewood u-joint before going to 4ft ladder bars. Also running turbo 400, dana 60, dana40 and posi frnt/rear. Now, I think if I had this in my vette how the hey would I ever hook up? Big Block power rules.

 

the bb may have a smaller stroke but the weight of the crank is incresed over a small block.
Also, unless you're on a budget, why are you comparing small big blocks(427)? You can get 500+ ci crate motors for a decent price, and if you build it yourself, then the extra flow you can get from the heads and the extra cubes will make power easier as well.