Does anybody have a spare copy of the SuperTruck Engine handbook that GM put out years ago? I'm trying to find as much information as I can about early NASCAR SuperTruck engines and this book was recommended to me.

Edit: I guess nobody has a copy of it.

Does anybody have any information about those motors? They are over 10 years old now, so secrets can be told.

Some of the info that I've seen says that they were 350-358cid, but some sources have lead me to believe that some teams used smaller bore 350 based blocks with 18 degree heads? Can anybody confirm or deny this info? Does anybody know hwat kind of power these engines made?

 

bump for the edit

 

not sure on the super trucks, but nextel cup runs a 400 bore(4.125) and a shorter stroke (3.25-3.0 not sure anymore)to get 358 ci. To get any real usable power they need to be turning 7500-8000 rpm.

 

they turn about 2000 RPM more than that these days

The reason I ask in the first place is that I picked up a set of unused pistons that Wiseco claims were ordered for a SuperTruck engine back in 1995. I'm having a feeling that the team found out that other teams were using big bore/short stroke combinations like you said, and then moved to that before using these.

The piston specs are 4.028" bore, 1.125" compression height, 1/16, 1/16, 3mm rings, 14cc reverse dome, .920" pin (I actually measued these to .924"), 2.300/1.750" valve notches for 18 degree heads.

I'm wondering about how much power these pistons will be able to take so I don't build something too strong for them

 

Looks like a good piston for a 6" rod 383 with 18° heads to me ;-)

Bret

 

That would give me around 11:1 compression depending on where the heads end up.

I could probably run a 3.8" stroke with a 6" rod also. That would give about .15:1 higher compression.

In an effort to get the highest compression ratio possible, I was thinking about a 3.875" stroke with a 6" rod which would put me .0375" out of the hole. I could machine some more material out of the top of the piston to make that a bit more reasonable, but then the compression height will be pretty dang small. It would take the reverse dome CCs much smaller, but I haven't bene able to figure out just exactly how much.

I'd also like to figure out a way to run a 4" stroke if possible.

 

Don't worry about that stroke issue, run the 3.75-3.80" crank.... What are you using for a chamber volume here? 50-55cc is pretty common for what you want to do. That gives me a 11.4-12:1 SCR, works for me.

Bret

 

I guess I like higher compression motors

I have seen 4.100" SBC crankshafts and that would work perfectly with these pistons and a 5.850" rod. I know that I'll have to do a good bit of work to the block, but I'm not too worried about that. The block will be half filled.

I just wish I had some idea of how much power these pistons could take so I don't make the engine too strong!

One thought I had was to build a 6.125" rod 355 with big head chambers to get compression around 10.25:1 and then put a blower on it. But I'm afraid about the pistons still.

Here's another thought I had 3.625" stroke + LS7 Ti rods (6.067") and just put a carb on it so I can rev the **** out of it. Barry Grant's new inline 4 barrel "BAD MAN" carb would definitely be interesting to see under the hood.

 

No more cubes the better...... I don't see how 12:1 and a 383 would be bad? Remeber old Mindgame?

Bret