SB2 Motor

[ProdigyCustoms]

The SB2 may very well be the most HP for the dollar in a motor for the wise shopper. There are a bunch of Nascar used parts guys selling almost everything you need used. For the most part this is either one race, or qualifying stuff that is perfectly fine. The horsepower, as in any motor, with SB2 is in the heads. SB2 heads flow big block numbers, high 300s is no problem. Using the 2HP per CI, you can see it would be easy to get 750 to 800 from a SB2. There are some things to watch out for though. Intake runner sizes can get huge, remember Nascar guys really do not worry about low end torque much, but camed properly, along with other correct component selection can minimize torque issues A Pump gas SB2 will require a very special dished piston for NA application, and it is almost impossible to build a blower piston with 3 rings, especially for bigger cube motors, for a SB2. The heads range from a small size of 46CCs to a max of 54CCs or so, and do not have much room in them to be opened more then mid 50s, so we are talking serious dish pistons here. If you decide to make some cubes (Hot ticket to make up for the torque issues of the too big heads), then you are looking at more compression issues trying to keep it down in the 11 : 1 range, but it can be done. The cam is a totally custom piece not only to the motor, but in the way the lobes are cut. It requires a short lobe to keep lift down to .700 to .750. Used Jessel rocker set ups are anywhere from 1.6 to 2.2, most being closer to 1.8 to 2.0 range. So it can be hard to find a smaller set of rockers. The intakes that are available are big, so again the low end may suffer, but suffering here may be like driving the old Ferrari because the new ZO6 is in the shop for service.

I spent a lot of time specking one out for Prodigy before the big block decision was made. I do not have my spec sheet and cost anymore (computer crash), but if memory serves, using a new block, rotating assembly, and cam with used everything else, $12k would build a all aluminum 427 CU SB2 that should make a tick north of 800HP on pump gas. You wanna talk about a lightweight, nasty sombitch! Just talking about it makes me think about it again, but right now I am seduced by a 500" LS1 idea. But we ain't talkin $12k either.

If anyone gets real serious about doing one, I can help, and I also have a friend at Bill Mitchell doing one right now for his own PT Camaro.

[MarkM66]

Frank, don't the SB2 heads that the Busch series guys use have larger combustion chambers? I thought those guys had to run like 10:1 or so.

[race-rodz]

i looked long and hard for the biggest chambers i could find, mine are 54's, i have yet to order pistons, so the final comp ratio isnt set in stone. the torque issue will be interesting with my small inch motor, in a lite vehicle. the idea was to have a chance at getting rolling without blowing the tires off or breaking parts....and since my end goal is extended high rpm road racing, the combo should work out well. all totaled up doing as much "value" shopping for used high dollar race parts, my engine should come in at about $8k

[ProdigyCustoms]

The 54s usually are Bush heads as a matter of fact. I should have mentioned that. RaceRod, I like your idea. Having had a lot of high HP street cars, torque goes from friend to enemy when you get up to 600+. Or in your case in a flyweight. Besides, RPM motors are fun. Next week we will start a 64 Falcon, and plans right now are looking like a 331CI 8500 RPM motor. Those things weight nothing.

[Y-TRY]

I think I remember CompCams' white '69 was running an SB2 set-up. Something like 650 NA, pump gas. I actually remember liking the high-end torque they made (peak tq was at like 6k or something). That was my dream engine for a while and I was circling Ebay like a shark.

I just remember them being the hot ticket a while back, along with 18-degree heads. But with Lsx engines coming into play the hooplah kinda subsided.

[ProdigyCustoms]

LSX are cool and sure can be bad boys, but HP to Weight to CI to Dollar, nothing beats a SB2

[race-rodz]

i figured taking advantage of the millions of $$ r&d work for some slightly used parts was deffinatley the way to go, assembled heads/intake/shaft rockers/ valve covers w/oilers....... $3700 to the door.

[JUSTANOVA]

Originally Posted by race-rodz

i figured taking advantage of the millions of $$ r&d work for some slightly used parts was deffinatley the way to go, assembled heads/intake/shaft rockers/ valve covers w/oilers....... $3700 to the door.

was that ebay stuff or do you have another source? Also can you run the sb2 stuff on a normal block or do you have to run the sb2 block too?