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433 Bbc Vs 425 Sbc

20K views 65 replies 14 participants last post by  4 Jaw Chuck 
#1 ·
I am looking for your opinions based on your experiences here.

I am sloooooowly building a war chest to fund a Pro-Street car or truck.

Useage will be Cruises of 5-60 miles at a time, racing at local tracks such as Summit Motorsports & Dragway 42, show at local cruise ins & shows.

Judging by articles & books it sounds like the SBC has closed the performance gap with its larger kin the BBC.

Which would you build to have 600-700 HP at the flywheel w/o using N2O?

{Fuel will be 66% Pump E-85( 96-105 octane) blended 33%with Rockett Brand E-85( octane 112).}

I) A 436 cid SBC based on after market forged components( Motown Block 4.165 bore,6 inch rods,4.0 crank, solid roller cam & lifters) expected power band (2800-7000 rpm) 11.25-12.5:1 CR

II) A 433 cid BBC based on a production block & forged aftermarket components ( +.030 bore 454 block, 6.35 inch BBC rods, 3.76 inch crank, solid roller cam & lifters) 11.25-12.5:1 CR
 
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#3 ·
I agree, why hamstring the BBC with such a small stroke, go stock 454(4") at least, it will still rev comfortably into the 7500 rpm area if you put big enough heads on it, and more than meet your power goals. If you are buying forged crank, going to 4.25" stroke is a no-brainer.

The SBC w/23° heads will need the best of everything thrown at it to reach 700 hp naturally aspirated unless you go to 18° heads, still going to have to turn it to 8000 rpm.
 
#6 ·
This is one case where the BBC would actually be cheaper than the SBC. I have built two SBC's that make 800+ HP naturally Aspirated. One was an 18 degree 421ci that cost around 20,000 and made 817 HP at 7200 RPM and the other was a SB2.2 358ci that cost around 40,000 and made 850 HP at 9,000 RPM.

But I have also built a 632 that made 1200 HP for 20,000 dollars.

When you get into anything over 500 hp you have to really stress a small block and buy exotic blocks and heads to make it live. But at 600 to 700 Hp a big block is just hitting its stride. It is easy to make 700hp with a stock tall deck block and decent heads on a bbc.
 
#7 ·
I second what double_v23 said. You said you wanted a 427 right? A 427 tall deck has a steel crank like a 366, will handle lots and lots of power and save you some bucks. 700 horses would be very easy to get with the high compression that you can run on alky, you wouldn't even need a wild cam. With a solid roller cam and good heads who knows? Maybe 900 horses!! Theres a 427 tall deck and crank on craigslist already been block prep for 400 bones!! I wish I had a race car... BTW you might already know this but theres going to be forty eleven people trying to tell you to build a stroker motor. Because 900 hp isn't enough... Let me tell ya, that extra little bit of hp you might get from a stroker motor costs a heck of alot of money and you might actually end up getting less power because you cant turn the revs anymore. :evil: People hate me.
 
#8 ·
Which is the better option for a BBC, a 427 Tall Deck Block or a 502 block?

I am thinking 4.5 inch bore for the 502 but with a 3.76 inch crank for 478 CID or 4.28 bore for the 427 block for 433 CID?

I read in an old copy of Super Chevy about a 3.875 inch stroke crank for BBCs is this still available?

If it is I could build a 452 CID(4.31 bore with a 3.875 inch stroke) BBC based on the 427 Tall Deck block.
 
#9 ·
BottleBaby said:
Which is the better option for a BBC, a 427 Tall Deck Block or a 502 block?

I am thinking 4.5 inch bore for the 502 but with a 3.76 inch crank for 478 CID or 4.28 bore for the 427 block for 433 CID?

I read in an old copy of Super Chevy about a 3.875 inch stroke crank for BBCs is this still available?

If it is I could build a 452 CID(4.31 bore with a 3.875 inch stroke) BBC based on the 427 Tall Deck block.
A 502 (nominal 4.5" bore x 4" stroke) w/a 4-1/4" crank gets you an easy 540 cid. Or 40 more cubes than the same stroke crank in a 427/454 bore (nom. 4.250") block. No contest, IMO. Cubes rule- to build a "small" BBC is shortsighted- again- IMO.

FWIW, to get 900 NA HP out of a 427 is not easy. Or cheap.
 
#11 ·
I aggree with all about the BBC being a better platform for a high HP engine.

One thing no one has mentioned. When going to cruise-ins, car shows, or whatever, the BBC is the biggest WOW catcher out there in the GM world.

Nothing looks cooler than a BBC with Aluminum heads setting in any engine compartment.
 
#12 ·
Overdriv said:
I aggree with all about the BBC being a better platform for a high HP engine.

One thing no one has mentioned. When going to cruise-ins, car shows, or whatever, the BBC is the biggest WOW catcher out there in the GM world.

Nothing looks cooler than a BBC with Aluminum heads setting in any engine compartment.
I respectfully disagree with that. Forced indction gets the most looks, and a roots blower is still king when it comes to stealing the show. There's also some LS, northstar, and even polished up V6's that draw far more attention than "another BBC". For the wow factor the BBC is VERY overdone and at this point boring.

Sure makes a car go fast though! :thumbup:
 
#13 ·
I am having trouble understanding why you are trying to go with all these different strokes and bore combinations that are uncommon and therefore more costly.

A 427 block is the same as a 454 block. A 4.250 stroke in a .060 over 454 or 427 gets you 496 cubic inches. This is a common upgrade these days, it is like the big brother of the 383 "stroker" (I hate that term....Every engine is a stroker).

Less common and considerably more expensive is this 502 that you are speaking of. An .080 over 454 (or 427) with a 4.250 gets you close to 505 cubic inches. And would still be less expensive and more common than a "502" as defined by the GM 502 crate motor. 4.500 bore and 4.000 stroke (or something like that)

Cubic inches don't care how they are made. They make similar power whether you have a 5.000 stroke and 3.000 bore. or if you have a 3.000 bore and a 5.000 stoke.

The difference comes in when you factor in what type of materials you can afford, what RPM you want to run the engine, and what you will be doing with the engine and vehicle.

For example GMC made a V-12 that was over 700 cubic inches back in the 60's. It made tons of torque but couldn't turn more than 2500 RPM because it would destroy itself. But it was great for heavy duty trucks with 18+ gears.

In short, Get the most cubic inches that you can afford that will run in the RPM you want to run. If you spend money to get some exotic parts combination that is less cubes....it is like showing up to a track meet in ski boots, yeah you can probably go just as fast as the other guys but it is going to take a lot more effort. (ski boots=less cubes and more effort=time and money)
 
#14 ·
BottleBaby said:
Which is the better option for a BBC, a 427 Tall Deck Block or a 502 block?
I am thinking 4.5 inch bore for the 502 but with a 3.76 inch crank for 478 CID or 4.28 bore for the 427 block for 433 CID?
I read in an old copy of Super Chevy about a 3.875 inch stroke crank for BBCs is this still available?
If it is I could build a 452 CID(4.31 bore with a 3.875 inch stroke) BBC based on the 427 Tall Deck block.
I don't understand why you are so insistent about wanting less than 500 cubic inches. What's going on in your brain? Why all the wierd combinations?
 
#15 ·
Yep

Cubic inches don't care how they are made. They make similar power whether you have a 5.000 stroke and 3.000 bore. or if you have a 3.000 bore and a 5.000 stoke.[quote DoubleV23]

I like the way you think. Ain't no point in re-inventing the wheel. Power comes out pretty close one way or the other. Use the common parts for the most cubes. I think that the high price of big block HP heads makes people start looking at big cube smallblocks including me. :( olnolan
 
#16 ·
turbolover said:
I respectfully disagree with that. Forced indction gets the most looks, and a roots blower is still king when it comes to stealing the show. There's also some LS, northstar, and even polished up V6's that draw far more attention than "another BBC". For the wow factor the BBC is VERY overdone and at this point boring.

Sure makes a car go fast though! :thumbup:
No doubt it's a personal preference thing. I would agree that the sight of a roots type blower setting on a BBC looks pretty awesome and gets the most looks. But still, the cruises and shows I go to there are so many cars with SBC engines, it's like 69 Camaros, I like 69 Camaros, but seems everyone has one, but that's off topic.

Anyway, for more than one reason, I think BBC is the better way to get to your 700HP range.
 
#17 ·
BottleBaby said:
{Fuel will be 66% Pump E-85( 96-105 octane) blended 33%with Rockett Brand E-85( octane 112).}
I) A 436 cid SBC based on after market forged components( Motown Block 4.165 bore,6 inch rods,4.0 crank, solid roller cam & lifters) expected power band (2800-7000 rpm) 11.25-12.5:1 CR
II) A 433 cid BBC based on a production block & forged aftermarket components ( +.030 bore 454 block, 6.35 inch BBC rods, 3.76 inch crank, solid roller cam & lifters) 11.25-12.5:1 CR
Sounds like you are keeping the BBC inside specific CID limitation for a reason. You didn't mention the SBC, but I got the impression it would be a 421 to 434?

:pain: With this Lynch Mob brewing I'm getting off the sbc subject myself :pain:
 
#18 ·
Thank you all for your honesty.

The odd combos come from engines that I knew would Rev( N2O makes alot of TQ at the RPM it is needed), so I was looking for a shorter stroke and less than 500 CID. ;)

Last year Muscle Car magazine had an article on the F.A.S.T. racing class of Stock appearing cars. In this article was a Corvette with a 511 CID based on a 454 BBC. It featured a 4.375 inch bore and a 4.25 stroke( the bore was a full 1/8 overbore and the stroke is common) I have also seen this in Car Craft with a 4.31 bore(+.060) and a 4.375 inch stroke.

My question is which is easier to build from the stand point of availabilty of usable blocks & commonly produced cranks( production or aftermarket)?

How many off Y'all have had a Tunnel Rammed combo on the street, is this a waste of time with the newer single plane single four manifolds?

Thanks again!
 
#20 · (Edited)
I love this thread. It has my vote. In my opinion for whatever its worth, I would go 427 tall deck because you could cram more stroke in there than a short deck bigger bore 502 if thats what you want, or use that great forged 3.766 inch stroke and long rods, great heads, dual carbs and crazy cam to turn more revs. Or, keep the 427 dumptruck motor mostly stock and slap some big heads and a roots blower on it and really burn some gas. Same piston height as the 366, I know of a guy that took a 366 school bus motor and had great luck by just slapping a supercharger on it. With a piston that thick you can handle more heat and hence boost. Heck, I might could speculate you could burn some of the top of the piston off and never even notice. Not trying to be funny. If I had a blower and a budget that's exactly what i would do, a running 366 for 400 bucks, fresh pistons and rings, blower. Or a 427 tall deck, long rods, skinny pistons for a 4.25 bore(there are lots of them for the stroker people, and lots of long rods too) and solid lifters and huge heads manifold and dual 4 barrels. Long stroke can't rev as high, you can often end up with greater peak power with less stroke sometimes. But they are right in that longer stroke can make greater peak torque. It just does it much lower in the rpm range. It really depends on where you want the rpm to be that it peaks. Merlin even makes super tall deck blocks for that very reason if money is no object. I think simply however, and to me, revving a motor of great displacement to an ungodly rpm (it has an effect on people trust me) is about the coolest thing there is. A blower is of course, very cool too. Not trying to make a joke btw. I wish I had 4 427 blocks laying around instead of 4 small blocks. With a 427 tall deck you could make a 454 that would easily beat a short deck 454 anyday you wanted to with any old crappy 454 cast crank, some 6.535 rods and some cheapie 454 pistons. But WHY???? Or yeah, I forgot. To show that the tall deck is better. Imagine a 427 that can rev just like a 327, only it is 100+ cubes bigger and has has wayyy better heads..... Rpms are where the fun is in my book and you wont find that with a super stroked mouse motor, or any super stroked big block motor either. Not saying those motors arn't cool in there own special way, they have there place. Maybe like a tractor pull or something or a massively heavy vehicle with very very tall gears and overdrive. Everybody has there own thoughts about what they think is good or best, and if nobody agrees with the angle of your attack it does not necessarily mean it will not work. You can do it anyway you want! That's what it's all about and be sure and keep us posted of the progress! After all, this is still America, land of the free, last time I checked.

Big stroker motors are ok, but you better have the gears and you are still going to burn more gas all the time especially if they are not tuned to low rpm. You can get some real velocity going with rpms and a properly tuned intake and exhaust is key. Trying to make a super long stroke motor breath well at high rpm can make it very inefficient at low rpm because of the huge runners you would need, and that slows velocity and inertia at low rpm. But that's the range it is naturally good at! Defeats the purpose kinda to me at least. But a shorter stroke motor can still make decent power at low rpm but at the same time rev up like crazy if you would like to feel very afraid and make your hands tremble. Or at least make your passenger freak out.


Think: a short stroke motor can be made to have a pretty flat power band and can double the rpm 3 times over. 1000-2000-4000-8000 But a super long stroke motor can double its rpms like twice maybe. 1000-2000-4000.

With the right heads, cam, valve train, and exhaust etc. a 427 at 8000 rpm can breathe the same as a 854 inch motor at 4000 rpm! Yikes!
 
#24 · (Edited)
cobalt327 said:
OK- but how high do you have to spin a 427 to equal a "854" at a lazy 5500 rpm?

The TD production truck block doesn't fit a bigger stroke, it has 'room' for longer rods.
No such thing as a 854 turning 5500 lazily!! That is completly absurd! Try it!!! C'mon!

"The TD production truck block doesn't fit a bigger stroke, it has 'room' for longer rods."

Where the heck did you hear that?
What makes you think that??? What does that even mean? It isn't making sense to me.

It is the same bottom end as a short deck only with more cylinder height on the top! Theoretically it could allow for even more stroke than a short deck with same rods!!! If you really wanted a super long stroke motor without dishing out serious dough for a extra tall deck merlin block what other choice is there than a 427 truck block with 10.2 deck? C'mon you guys.... You can do better than that... hehe :nono: :p
 
#25 · (Edited)
If you already have it all sorted out, why do YOU not just do it already!

How do you think that a higher deck would make for any larger clearance inside the crankcase for more stroke? Have you ever even seen a TD BBC? Or ANY BBC?? Only if the stroke was to the extent that a pin couldn't be fit to a piston would the deck height come into it. The physical dimensions inside the engines are identical AFA clearance for counterweights and rod to rail or cam clearance goes.

Do you have any clue for what it takes to run a 427 @ 8KRPM, reliably? More to the point, do you have a clue, period??

FWIW the IHRA P/S "Mountain Motors"- 900- PLUS cid- turn just a tiny bit more than 5.5K RPM- reliably. How about 2070 HP @ 8100. 932cid. NA. Carbureted.
 
#26 ·
cobalt327 said:
If you already have it all sorted out, why do YOU not just do it already!

How do you think that a higher deck would make for any larger clearance inside the crankcase for more stroke? Have you ever even seen a TD BBC? Or ANY BBC?? Only if the stroke was to the extent that a pin couldn't be fit to a piston would the deck height come into it. The physical dimensions inside the engines are identical AFA clearance for counterweights and rod to rail or cam clearance goes.

Do you have any clue for what it takes to run a 427 @ 8KRPM, reliably? More to the point, do you have a clue, period??

FWIW the IHRA P/S "Mountain Motors"- 900- PLUS cid- turn just a tiny bit more than 5.5K RPM- reliably. How about 2070 HP @ 8100. 932cid. NA. Carbureted.

"If you already have it all sorted out, why do YOU not just do it already!"
I do not have the money. However that has not stopped me from thinking about it! Have you the money to prove I am wrong?

"How do you think that a higher deck would make for any larger clearance inside the crankcase for more stroke?"

I did not say it would. I simply stated that you could have a bigger stroke with the same rods if you read my post.

"Have you ever even seen a TD BBC?" Yes I have. They are nearly the same looking. Easy way to tell without looking at the casting number is the space above the water pump bolt.

"Or ANY BBC??" You are clearly taking this way too seriously and making a post based on your emotional reaction rather than a logical argument here. But to answer your question: Of course! I have a 454 in my van now.

"Only if the stroke was to the extent that a pin couldn't be fit to a piston would the deck height come into it."

So let me see if I understand what you asked.. if you had a long stroke crank you wanted to use and the pin height of the piston was too short to use with any rod that would work, then you couldn't use the crank right? Well a tall deck block might let you use that crank and rod combo you wanted. So a tall deck block would let you run a longer stroke in that case.

"The physical dimensions inside the engines are identical AFA clearance for counterweights and rod to rail or cam clearance goes."

Did I not say that earlier that they were the same?

"Do you have any clue for what it takes to run a 427 @ 8KRPM, reliably?"

I would say that to run any motor reliably at 8000rpm is pushing it unless you have a purpose designed engine like nascar or F1. I was using it as an example, but to run some short bursts up to that speed is not above the realm of possibilities for a 427 tall deck with solid lifters, long rods, stock 3.766 stroke and great heads with huge carbs.

"More to the point, do you have a clue, period??"

I think that is some kind of attack on me, even tho I clearly stated I was simply saying my opinion, you had to throw that in there to try to make me feel bad somehow. I feel sorry for you man, you must have had a rough day, or a rough life, to have to to try to make others feel bad about themselves. Misery loves company maybe true, but it didn't work this time guy.

"FWIW the IHRA P/S "Mountain Motors"- 900- PLUS cid- turn just a tiny bit more than 5.5K RPM- reliably. How about 2070 HP @ 8100. 932cid. NA. Carbureted"

How much did they spend on that motor is my question? That may be an exception, but I do not think that kinda performance is what this post is about. Why I bet with unlimited budget I could completely design a entirely different motor that beat that. What about the GMC Big Block V6/V12 somebody mentioned earlier? I bet with its short stroke and forged crank I could even make it spin alot of rpms.. Might take some super porting on the heads, custom cams... custom lightened pistons and custom rods... Anything is possible with enough CASH. Dude. C'mon.
 
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