Quickin

Just curious. Does a BBC make more, safe power than a SBC would with the same 93 octane gas?

There's 1,000 fwhp BBC using 93 octane.


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Villain281H

iTrader: (5)

pump gas doesn't care about what motor it goes in, just the compression ratio and heads. I think the rules are pretty close to same on what normal allowable limits are for pmup gas for compression ratio and such...

Quickin

So a 427 BBC and a 427 SBC, both at 11.1 compession and everything else being the same, will have the same power pretty much?

Scalpel

iTrader: (4)

I think a 427 BBC will make more power at a higher RPM vs 427 SBC due to the larger bore size allowed by the BBC on the same gas, holding all else the same.

Strokinit383

iTrader: (22)

But they are the same displacement. What the sbc loses in bore size it makes up for in stroke correct?

Turbo LS1 SS

iTrader: (7)

obviously

jshiver

iTrader: (6)

I think the BBC would get you more "grunt"

Quickin

I would think the shorter stroke of the BBC would be the only difference, by way of making its HP in the higher rpm's. But I don't see why it would make more than the 427 SBC, give or take a few. Should be dead even engines in the same car if they race.

Right?

Quickin

572 GM crate engine.....9:1 compression.........620 fwhp

My 436 small block....11.3:1 compression..........about the same fwhp ~620

I can only conclude from this that more cubes means a whole lot more than compression does. But than I get confused again because all GM does to that same 572 crate engine to make 720 hp is send it out with 12:1 compression.

Quickin

So, the question still remains.

Why would a BBC make more power than a SBC with the same octane. LSx engines need C16 race gas to make 550-600 HP if a small 348 or 383 is used, but a BBC can make 1,000 HP easily on 93 octane. And from what I was told by the builder of that 1,000 HP BBC is that it can make a WHOLE LOT more on pump gas with bigger heads and a bigger Procharger.

Also, that 1,000 HP BBC making 1,000 HP has a small Procharger on it already.

jshiver

iTrader: (6)

It is Black Magic....In my experience, Big Blocks have always had a better torque curve and seem to make power easier. I have no doubt that you can make a small block (the same c.i.d)make the same power numbers...But, it will be own up in the rpm range...Big Blocks don't turn up high rpms as well as small blocks. Just my thoughts

Quickin

I was really trying to figure out why a BBC can make double the power a small block can and BOTH of them cannot use the same gas. The small block needs race gas to do anything worth talking about.

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LS1SSII

iTrader: (2)

You have to remember that a Big Block Head is not the same as a Small Block Head. You are going to find all of the power in the heads and cam.

Villain281H

iTrader: (5)

there have a few big block vs small block build ups on same cubes, compression, cam #s etc. Big block makes more power and torque, but the added weight offsets that somewhat, but the big block usually is faster by a tenth or so.

I disagree on the small block needing race gas to do anything worth talking about. a 427 small block making 600 ponies on pump gas is slow?

Derek

slow trap

iTrader: (22)

the mags dont the same displacement comparison and as allready stated the big block made more power but at the expense of around 150 more lbs.it is obvious a much larger engine will move more air than a smaller one so the 572 will easily out-pace the sbc.

CarelessAndImprudent

the big block with make the power down low, while the small block with make it up high if its built strong enough to reliably rev

Quickin

600 hp is cheezy and weak compared to the 1,000 hp BBC on the same 93 octane. For a SBC to get anywhere near say 750-800 it needs race gas. My 436 makes 600 hp on pump gas, I'm just trying to see why a BBC can make so much more power, with everything else being the same, except the cubes. I guess better airflow of BB heads allows the power to go way up and still keep using pump gas.


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TimTaylor75

iTrader: (4)

Two days ago I stopped by Fowler Racing Engines to gather information about my upcoming engine build. I mentioned that my main goal is to reach the 500 hp point. I mentioned that I was planning on just building a SBC and would like to run pump gas. I was informed that might be pretty much not possible out of a SBC even a stroker setup. He mentioned that the reliability would be the main issue. I'm nixing the SBC and going with a BBC as he mentioned that it will be more achievable and reliable. Not to mention that the cost would most likely be lower.

slow trap

iTrader: (22)

500 hp is easily achieved with a 383 or 406 on pump gas,and well under 6500 rpm.everybody has there own opinions but 500 hp is well within reach of reliable .

Quickin

Wait a second, you may not want to use Fowler as they sound extremely incompetent, unless there's been a misunderstanding. A small block can make 500 hp without even breathing hard, on pump gas, and idle as smooth as a stock small block.

I have a small block, its a 436 stroker. It makes 600 hp and it idles just like a stock, factory car. 93 octane. It's almost 2 years old and its running like the first day it started up. So its ridiculously reliable.

Maybe you misunderstood them about NOT being able to make 500 hp with a small block, because its been done to death. 700 hp is doable with pretty nice idle quality and still good reliability.

The only thing I agree with is that a big block making 500 hp as opposed to a small block making 500 hp is: The BB just won't be working as hard. But 500 hp is basically a joke for either engine these days. As I said, my engine is very very very mild, and I make 600 hp. Only thin I had to do to it in the past ~2 years is change the oil, air filter and spark plugs.