JustinsWRX

Would there be any performance difference between a 427 SBC and 427 BBC? Cubes are cubes correct? Would the SBC be any less reliable?

sprojam

interesting ? is the bore an stroke the same on these engines it seems to me there wouldnt be much material left on the small block but ive heard they go as big as 454 is this done on a stock block or do you have to step up to the after market? i dont think so you get cubes two ways bore an stroke

Rydda

i was talkin with my mechanic about that very thing the other day, he said they used shorter rods and very short pistons. cant remember if he said anything about the crank but the fact that they have found a way to pull that many cubes out of a small block is frickin amazing

sprojam

i agree and yes it is i just wander if they are using production blocks

five7kid

iTrader: (14)

No, they aren't the same bore and stroke. The SBC 427 is 4.125"/4.00", the BBC is 4.250"/3.76".

Rods: 6.385" vs. 5.7".

Valves: 2.19"/1.88" (typical) vs. 2.08"/1.60".

Ports: "Small" BBC heads (truck peanut heads excepted) will flow similar to "large" SBC aftermarket performance heads. "Big" BBC heads available from the aftermarket.

Factory 427 cranks were forged. You'll pay extra for that in a SBC 427.

The extra weight of the BBC is easily overcome by the extra power it will make. Unless handling is your primary use, the weight isn't an issue.

The BBC will handle more power produced than the SBC.

BBC 427 is internally balanced.

Big SBC's are cool, but I wouldn't start with anything but an aftermarket block.

BBC will be less expensive to build.

BBC gets my vote.

Z28guy83

but with a big cube sbc you can always tell people its a 305

KrisW

iTrader: (5)

Stealth is cool on the street.

Very cool.

Small block gets my vote, as long as you do the engine block right. No slap together jobs for something like this!

five7kid

iTrader: (14)

For the same money spent, the SBC would be quite a bit less reliable.

zz4monte

I have been thinking the same thing.World motown block!!!!!!Heres the thing.Like five7kid said, for alot cheaper you can build a big block. Yes it can't be a sleeper when you lift the hood but I got a price for a 496 stroker shortblock for around 2,500 bucks. This was not a race motor but it had a good new crank, H-beam rods and forged TRW pistons. The builder said he would have no problem pulling 500hp with a mild cam that didn't lope and a good set of heads.The extra weight really isn't a factor when you have 600+ftlbs of torque.$5,000 bucks can get you a wicked big block with 500+hp and daily driveable or $7,000+ for a world crate motor. I am sorry but I am a best bang for the buck kind of guy. Plus a 427 vs 496 is like a 305 vs 383.Hell you could build a 540 for cheaper I bet!!!! 502 with a 4.250 crank. Talk about back problems.

zz4monte

Here is another big block short block that he will do for around $2,000 just like the other block.The engine builder was telling me about how many 396 blocks he had laying around and that no one would buy a 396 because they think its a boat anchor.He has made 3 396 stroker motors. Comes out to 436 cubes I think he said.Basically it's a 396 bored out with a 4.000 stroke.He says its cheap because the 396 cores cost so much less than the 454 core and that a 4.000 crank is a standard big block crank.Anyways he built two of the motors that both made over 470hp for under $3,500 and they are very daily drivable.The other one was pretty much a stroker with a stock type cam and a head port.I think he said it made around 400hp.Either way 470hp for a big block that costs about $3,500 bucks is pretty cheap.

JesasaurusRex

iTrader: (3)

Big Bore Short Stroke will always outperform Small Bore Long Stroke, cubic inches being the same. The cylinder heads you can get for a BBC sh*t on a SBC dollar for dollar. Im not saying their arent any good flowing SBC heads, hell look at the SB2.2's. Then again, getting bbc headers to fit into a 3rd gen is probably a chore and a 1/2. The ones Hooker makes are tiny for a BBC (depends on the cubes ofcourse, would probably be fine for a decent 396, but if ur gonna get a bbc why build a 396? Just depends on what you want to do and how much power you want to put out.

AlkyIROC

There was a magazine test a few years ago on a 408 SBC/BBC. 400/396. Both having the same grind cam. The BBC needed larger tube headers to breath. If everything was equal, the engines performed roughly the same. Using the same car and swapping engines, the BBC ran slightly quicker.

But why stay equal. A 427 using factory parts starts where an aftermarket equiped 427 SBC has gotten to. The factory BBC heads already flow roughly where some good aftermarket SBC heads are so port and polish the BBC or install some aftermarket ones and the engine really wakes up.

The BBC engine can take a much bigger cam without the problems that a SBC engine would have. Putting on some bigger headers is easier for the BBC.

If you want to compare apple to apples, there isn't much different but the SBC isn't stock to be equal to the BBC. If the BBC is allowed to do the same upgrades over stock, it will perform much better. Adding the extra 100-150 pounds of the BBC can easily be overcome with the extra power it can produce.

My engine is internally balanced and a short deck block. I can say it's only a 427 or 396 and nobody could well the difference from looking at it other than seeing the Dart name cast into the block.

It's not all about cubes but cubes help. A 302 chev can easily outperform a 305 chev because of how the bore and stroke is. A 500 Caddy engine is a torque monster but doesn't produce mega HP in relation to the cubes.

I like my 540 but with today's engines, it's considered small. The 572 is becoming popular and the 632 is becoming the real sleeper engine. Both are tall deck blocks so they're not a typical drop in engine swap. The 540 fits anywhere a factory BBC fits.

zz4monte

I never asked you Stephen but does that thing scare the $hit out of you when you floor it.
Fastest car I have been in is a high 10 low 11s car and that was scary fast.

QwkTrip

iTrader: (22)

Who lifts the hood unless they are racing for money? Nobody would suspect a thing.

sprojam

thats cool vid of your ride there hows that alcohol on parts ive had friends try it seems they dont live long at all

AlkyIROC

The faster you go, the slower it seems because you always want to go faster. I make a 9 second pass and it feels like it was only 12 seconds. The thing that scares me the most is hurting engines. I've broken quite a few in the last few years. I threw a rod at the beginning of June and finally fired up the engine 2 weeks ago. It doesn't so much scare me as it does surprise me at times. I've launched only to feel the steering wheel shudder. That's when the front end comes back down and hits the ground. Last year every time I launched, the car would pull to the right and I was yanking on the steering to straighten it out. I did some suspension adjustments and it launches straight now. Driving through the pits is a bit scary since I can't see anything on the passenger front side of the car without stretching my neck to see over the scoops.

I launch off the transbrake at 4500 rpm. I shift (powerglide tranny) at around 6500 and go through the traps at around 7000. It's over in less than 10 seconds so there's not much time to think about anything. I need to work on shifting into high gear sooner. Theoretically, I should be shifting about 200 feet from the start line.

I won't recommend alcohol for a street engine but it's a great race fuel. It's a bit more maintanence. If the car sits longer than 2 weeks, all the fuel including what's in the carbs gets drained. You need to do oil changes more often because of the condensation and alcohol contamination. At the end of a race day, the carbs are sprayed down with WD40.

An alcohol engine has a hard time building heat. I use a rad from a turbo Firefly. If I'm lucky, the engine is around 140* when I stage. At the end of the 1/4 mile, it's around 190*. By the time I get back to the pits, it's down to about 150*. That's putting about 700 hp to the wheels.

Pricewise, it's more expensive than pump gas but my engine won't run on pump gas. You'll burn about twice as much alcohol as you would gasoline. When you consider what it costs to buy C12 or C14 VP race fuel, a gallon of race gas is at least 4 times the price of 2 gallons of alcohol. I buy my alcohol in bulk from a local industrial supply house. It's just methyl hydrate. If I was desperate for fuel, I could run down to Home Depot if I had to but the price would be higher.

Sort of off topic but I just had to answer questions.