N2OBaby

Hey guys/gals I am new to Chevy.

I always was a Ford/Mopar guy but I joined the "Dark Side".

I am sloooowly saving to build a Pro-Street car or truck.

I have seen 427& 454 BBC converted to 511 CID some with a +.060 bore & 4.375 stroke or a +.125 overbore & a 4.25 stroke.

It also stroker SBC are all the rage now.

With a desired output of 600-670 Flywheel HP w/out N2O, E-85 fuel( Pump E-85 96-105 octane, Rockett brand 112 octane) and 12-13:1 CR which combo would be better a 434 cid SBC or the old work horse 427 or 454 BBC stroker?

ZONES89RS

iTrader: (25)

Depending on the parts involved, whatever engine can spin up higher would be the one to go with. If the big block only goes 6000-6500 and the SBC goes 7000-7500, i would go with the small block. Now, a BBC that goes 7000 or higher...decimation.

3.8redbird

iTrader: (3)

sbc is lighter
If I was going BBC I would want 540+

Whats the et mph goal?

suspension, trans, rear?

brucer

i think it would depend on what kind of sbc set up you were looking at, mainly the heads....

if your not going to get a set of heads for the smallblock that flow as well as a decent set of bigblock heads there wouldnt be a point in doing a smallblock.. your going to have to spend alot on a set of smallblock heads to make up the difference in the heads..

it might come down to the price of the heads being the deciding factor..

sure you can build a big smallblock, but the heads i seen and priced to get a big smallblock to flow compared to a big block were very high dollar items.. at that point it was more cost effective to go with a bigblock.

511 gonna make a $hitload more torque than a 434, especially on a bottle..

KCS

iTrader: (20)

BBC for sure. A 468ci BBC with mildly worked GM oval port heads can make an easy 600bhp on pump gas. Bump the CR to 12:1 and with over 500ci, you'd probably be closer to 700bhp.

You would need to spend a lot more money on a SBC to try and make that kind of power. The heads and valvetrain alone would probably cost as much as the entire BBC build. Not to mention, you will have to turn even more RPM than the BBC to make that kind of power, which is just going to be harder on parts.

cambirdracing

iTrader: (4)

I am with KCS, BB is easier to make tht much power without adders. Yes, heavier, but well worth it. And if you guys read agian, he said Pro-Street. I am suprised none of you suggested a turboed LS engine.

N2OBaby

As the post stated I am in the planning/saving stage but I do have some ideas.

Cam: Solid Roller N2O friendly

Rear Suspension: Chassis Bars w/ coilover shocks, steel wheel tubbs, M/T ET Street 30-13.5-15 or 31-18.5-15 tires.

Rearend: ARB Airlocker Dana 60 with 5.13 rear gear( with a 31 inch tall tire this is effectively a 4.30 rear gear) & a mono wheely bar attached to the Dana.

Trans: Transbraked TH400 with a 3600-4200 stall N2O convertor.

ET Goal: 10.60-10.80 OFF the Bottle & 9.20-9.60 ON

Would a Weiand Tunnel Ram with a custom single 4 top and an E-85 1050 Holley Dominator be a good intake & carb for this combo?

Oldsmobility85

iTrader: (1)

Another thing to worry about is if you have a converter that is rather designated to run its absolute best on the juice the motor will likely drag its feet without the spray due to lack of torque causing the engine to be out of its operating range for longer. I have seen small block cars run 5.20 in the eighth with a 300 big shot kit only run 7.10s without the kit. A big block if you aren't worried about the weight could more easily compensate for some of this loss.

It will probably take a deal more cash to build a small block with that kind of na power but thats primarily due to cylinder head cost. A big block can make the same kind of numbers with worked factory iron's. And with the small block you really dont have to have all those cubes if you aren't going to run a massive cylinder head either. If you are gonna stay 23* a good 406 with a 300ish cfm head and sollid roller setup can make those kinda numbers with a good buildup.

I don't know if anyone has priced any big stroker stuff lately but that stuff isn't cheap

brucer

go to my post titled 1980 chevrolet truck.
https://ls1tech.com/forums/small-blo...let-truck.html

i built a 402ci bb , small chamber oval port heads, 2.187/1.875 manley undercut raceflo valves,mild pocket porting/bowl blending, .565/.545 lift hydraulic cam,1.72rr's, 3800 converter, 4.88 gears...

i messed with alot of smallblocks, 355's,383's, 406's, the small 402 bigblock will just plain eat them, it revs like a smallblock and the heads flow like mad, the torque is literally dominating... if youve never built a bigblock, do yourself a favor and build one.. i dont think you'll be disappointed, especially in a prostreet setup... nothing sounds like a thumping big block.. except a blown thumping bigblock

only other thing i would do would be either a blown bigblock, or a blown ls1. if the big block was going fuel injected, the big block definetly..

Doug G

http://www.horsepowerinnovations.com/
That a buddies 427 SBC (Eric) he can help get/build you what you want/need

scramblerman

iTrader: (16)

Big block and don't look back.

supermouse4

Go with BBC, you'll love the torque and power from it.

87silverbullet

iTrader: (11)

A turbod ls engine would probably cost more than a SBC or a BBC build.

I guess I am the only one that would go a smallblock on this one. I just like the way a smallbock revs and with these big cube sizes they make these days the torque is pretty decent. At some point you have to stop on the torque because then it will be like owning a 2wd diesel: no traction, ask me how I know.

To reach the ET goals of the OP, 650hp will not be needed. A friend of mine ran 10.99 in a full weight f-body that only made 392 to the rear wheels.

hsyr

I would opt for the 434 SBC and some 9 degree Dart heads that have been worked over

BigRich954RR

iTrader: (1)

I would go Big block chevy if you go aftermarket parts you can get some crazy crazy stuff if your willing to pay the cash. second i then look into the LSX

cam2z

iTrader: (3)

My 434 sbc in a 3300 # 69 nova went 9.89 @ 140 mph .. This is a pumpgas motor with a 4500 stall, 4.11 gears afr 235 heads, Cam specs 264 - 272 714 710 109 lobe sep. On a 275 shot its been 8.70's not bad for my street car. I have about 12,000 in this motor from carb to pan. Not cheap but very reliable. So my votes is big small nlock

N2OBaby

I know I mentioned a 511 BBC(based on the 427/454) or 434 SBC, However given the availability & durability of the 502 marine block BBC this is pushing me away from aftermarket SBCs and smaller production 396/402/427/454 BBCs.

I have heard the 502 can handle 1000+ HP & can be overbored to 4.56 if it sonic checks.

I have talked to a few racers/show car guys who swear by Roots blowers.

I was thinking a 6-71 Blower/ Intercooler (overdriven 11-20% for 10-12 lbs of boost) and a 472 CID [destroked 502,using std 4.468 bore 8.75:1 pistons, 6.385 inch forged rods,and a 396/402/427 steel 3.766 inch crank] for an easy 600-800 HP w/o N2O and possibly more with a N2O fogger.

Wouldn't this path be easier/cheaper in the long run than a High CR,Tunnel Rammed, solid roller cammed, 509-557 CID, N2O injected engine?

3.8redbird

iTrader: (3)

The old roots blowers are VERY inefficient. Is turbo an option?

xx_ED_xx

iTrader: (17)

twin turbo BBC, unless you prefer a big thing blocking your view as you drive

3.8redbird

iTrader: (3)

Id like to see a 116mm front mount. would look beastly