Small Block & Big Block Chevy Specific - 93 octane and a BBC engine

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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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...

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...

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?

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.

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

obviously

I think the BBC would get you more "grunt"

I think the BBC would get you more "grunt"

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? :confused:

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.

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.

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

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

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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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.

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

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.

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

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

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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Two days ago I stopped by Fowler Racing Engines (www.fowlerengines.com) 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.

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 .

Two days ago I stopped by Fowler Racing Engines (www.fowlerengines.com) 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.

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.

Thanks for the clarification. Kinda makes me wonder in that case because what I posted above was exactly how the conversation went. My thinking is that he may have mentioned that to maybe safeguard themselves as a company? He mentioned that they'd rather build (in my case) a BBC to achieve those numbers to build me something (I'd be happy with for quite a while). They've been in business for 25 years, so I just may need to speak to them a few more times before an actual work begins.

Thanks for the clarification. Kinda makes me wonder in that case because what I posted above was exactly how the conversation went. My thinking is that he may have mentioned that to maybe safeguard themselves as a company? He mentioned that they'd rather build (in my case) a BBC to achieve those numbers to build me something (I'd be happy with for quite a while). They've been in business for 25 years, so I just may need to speak to them a few more times before an actual work begins.

If you're thinking BBC or SBC you really should talk to these guys as part of your research. I spoke with them last week about a sc'ed BBC or a SBC turbo build, they know what they're talking about, very impressed. I'm waiting on quotes right now.

wwwfasttimesmotorworks.com

You might inquire with some engine builders about the bore/stroke combination of the SBC vs BBC and which combination is more octane tolerant. From what I've read things such as piston dwell and bore size can affect detonation resistance. For example, a 427 SBC may or may not be capable of the same power output as a 427 BBC both on pump gas.

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.

600 hp small block in a car running 10's in the 1/4 N/A is cheezy? Man do I want your budget! My 383 makes about 370 rwhp through a TH400 and a street set-up (3500 lbs, all steel, full exhaust with tailpipes, 3.73 gears, 10" convertor), and I'd guess that's about 500 hp or so at the flywheel. It cost a good 6 grand to build, and I know building a higher hp set-up with a forged rotating assembly, aftermarket block and so on would push the $10,000 mark. For that kind of money, I'd go 9's with a big block N/A, but I think running fast with a small block is more impressive. I have yet to see a reliable 1,000 hp street car (and I don't mean a 600 hp car with a 400 hp shot of nitrous) that gets driven more than a few miles to a cruise-in then raced most of the time. These cars usually have more $ in their engine then I have in my entire car.

Okay I'm done ranting, I guess someone saying 600 hp is cheezy just means my shit is slower than I thought 5 minutes ago... :bang:

Derek

Quickin I wouldn't say your car idles like stock :lol:

There was a comparison of a 454 ci small block versus the the 454 big block in hotrod way back when. The engines made similar peak power but of course the BB made more torque in the mid.

In the end they put it in a Nova and ran passes with each motor. The BB won. Why? Torque is what moves ya and is what wins races.

No replacement for displacement.

The reason BBC makes more power is because like someone else said, it can breathe better. heads flow more, bigger valves, yadda yadda. The Beauty of BB is that you don't have to rev them that high.

God I miss my 396 Chevelle. :(

I seriously don't think a BB can make 1000 on pump gas. If they did a lot more people would be running them, especially at the PGD.

Quickin I wouldn't say your car idles like stock :lol:

There was a comparison of a 454 ci small block versus the the 454 big block in hotrod way back when. The engines made similar peak power but of course the BB made more torque in the mid.

In the end they put it in a Nova and ran passes with each motor. The BB won. Why? Torque is what moves ya and is what wins races.

No replacement for displacement.

The reason BBC makes more power is because like someone else said, it can breathe better. heads flow more, bigger valves, yadda yadda. The Beauty of BB is that you don't have to rev them that high.

God I miss my 396 Chevelle. :(

I seriously don't think a BB can make 1000 on pump gas. If they did a lot more people would be running them, especially at the PGD.

When I say a stock-like idle I mean I have no lope at all, no lumpyness, it doesn't shake and it just sits and idles smooth.

www.fasttimesmotorworks.com has the 1,000 hp (850 RWHP) Procharged 598ci BBC on pump gas. They sell them as a turn-key crate engine. The owner also told me that their gas up in Michigan has less octane in it than in Florida, I guess because of some additive for the cold, and it would run better down here on our 93 octane. Idle is set at 700 rpm on this engine too.

This guy has a 1,050 hp, pump gas 91 octane BBC. He has to have 91 octane for the race event rules. Damn thing idles at less rpm than mine. This engine has one carb and no forced induction so I'm sure it idles rougher than the Procharged one. The Procharged one idles very smooth from what I was told. But the question about 91 0ctane is well known and its been done to death, The guy at Gayle Banks said it can be done quite easily with a BBC too. Thats why I started this thread, I guess more/faster airflow alone, simply allows less octane. Thats all I can figure :confused:

http://www.hotrod.com/howto/113_0206_1000/index.html


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That motor from HotRod will cost you about 30 grand to build..

That motor from HotRod will cost you about 30 grand to build..

Yeah, the 1,000 fwhp FTM 598ci BBC is $26,000, ready to start up as a tuned and finished crate engine package. Comes with everyting from intake to oil pan. To upgrade the Procharger and heads to make 1,800 FWHP its another ~$3,000.

But you'll have an engine that will last a very long time and one that can be beaten to death. No LSx based engine at 1,800 fwhp (if one could even get there) could handle half the abuse and live. Thats the problem. And an LSx based TT or SC'ed or single T engine will cost almost as much probably.

Which would you rather have in your car is the question?


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I'd rather have a small block with twin turbos. Keeps the weight off the nose and the car more balanced.

I seriously don't think any Procharger is gonna add another 800 hp and stay on pump gas. 1800 hp no matter how you slice it and dice it is not gonna last and be perfectly maintenance free for miles and miles.

Whether you're at 1000 hp, 890 hp, 1500 hp, 1250 hp, etc you ain't gonna hook on the street, power like that is more for bragging rights than anything. If you think your car is nose heavy now and have problem spinning wait till you put that monster in it, the back tires may come off the ground, lol.

There's a lot of factors you aren't including, like fuel system, new bracketry for accessories, etc, custom built headers, exhaust, etc etc etc, not too mention labor to install, custom mtr mounts, making it fit in your bay, beefing up your front suspension.

need I go on? :lol:

If going fast were easy everybody would be fast.

I'd rather have a small block with twin turbos. Keeps the weight off the nose and the car more balanced.

[quote]I seriously don't think any Procharger is gonna add another 800 hp and stay on pump gas.

No, no, never said that. The 1,000 hp BBC clearly runs perfectly on 91 octane. There's many of them all over the place in race events that are limited to 91 octane as rules. Not an 1,800 hp engine.
DNE Motorsports Development builds the 1,000+ hp BBC for drag boats, they can only use 91 octane gas. And they use carbs. They can use FI which makes them more powerful. I've been reading articles on these crazy engines.

1800 hp no matter how you slice it and dice it is not gonna last and be perfectly maintenance free for miles and miles.

Whether you're at 1000 hp, 890 hp, 1500 hp, 1250 hp, etc you ain't gonna hook on the street, power like that is more for bragging rights than anything. If you think your car is nose heavy now and have problem spinning wait till you put that monster in it, the back tires may come off the ground, lol.

There's a lot of factors you aren't including, like fuel system, new bracketry for accessories, etc, custom built headers, exhaust, etc etc etc, not too mention labor to install, custom mtr mounts, making it fit in your bay, beefing up your front suspension.

need I go on? :lol:

If going fast were easy everybody would be fast.

I hear ya. Marko, Jose and FTM all told me that an LSX engine with a single turbo, either the GT55-91mm or the more recommended new S95, would make 1,500 RWHP.

I would also rather go the LSx way, just to make it easy. The "Street Killer" single turbo kit is $4,800. A built Warhawk, lets just go high and say $11,000.

$16,000.......could it be that cheap? TH400 and you're ready.

But I'm probably missing something here :jest:


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FIGURE 5 GRAND AS A BUFFER AND YOU'LL BE GOOD TO GO. They're still figuring out combos for these lsx motors.

if I had the extra scratch or if I banged a rich woman, for fun I'd build a serious, almost all out but not really weekend/street/strip car. 408 with Twins, Turbo 400 or built 4L80e, 9 inch, 10 pt cage, but full interior'd still. Only thing the car wouldn't have is A/C. It would be built similar to the white T/A from Livernois. simple combo that works. That car went 8.9 and was on streets of Michigan.

That's what I'm talking about!!

hey its only money!

So, the question still remains.

Why would a BBC make more power than a SBC with the same octane.

BBC Heads flow more

BBC Heads flow more

I'm just trying to understand more in-depth why the same octane can be squeezed in a given cylinder and not detonate just because there's more airflow. More air means you need more fuel, so ratios don't change, and are relative to the different sized pistons.

I guess it's because of airflow, but why and how?

:confused:


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you answered your own question
go here and read.
read about engines.

www.howstuffworks.com

theres no replacement for displacement hands down for what it takes to make a sb to equal what bb is already

Airflow = power. A small block head is going to be more limited as to the amount of air it can flow. It's just that simple. Combustion design, material, weight all play parts but the proof is in the pudding.

I will say right now though there are alot more 600hp pump gas small blocks running around than 1000hp pump gas big blocks.

I made 750 in my 468 on pump gas and I thought that was pretty impressive.

How about 1500? 1800? This nova is nasty!
http://procharger.com/chevy_nova.shtml

It's all in the heads. A big block 18 degree head flows sick numbers. 400+cc intake runners are huge and no small block runner is even close to that. The closest thing is the Dart little chief, it has a 310cc intake runner. Average horsepower is different than peak. A big block makes more average horsepower than a small block hands down.