I recently purchased a brand new zz383 bare block to use to build a stroker motor. It features a one-piece rear main seal, a 4.000 in. finished bore, an oil pan rail machined to accept a maximum crankshaft stroke of 3.800 in., and a lifter valley designed for hydraulic and flat tappet camshafts and lifters. The maximum cylinder bore diameter is 4.080 in. It's arrival I am told, may be delayed for another week. Anyway, while I wait for it I need to make some final choices as pertaining to the rotating components. I am unsure which is the best direction to go with the block. Correct me if I am wrong, but unless I take the block to a machine shop and have it bored .030 over I can only build a 377 (4.000 in. bore with a 3.750 in. crank) or a 382 (4.000 in. bore with a 3.800 in. crank). So what is the best way to go- 377, 382, or 383?


A little more info on my setup/plans: I have a Pro-Built 700r4 transmission with a 2800 stall Edge 9.5 in. torque converter. I also have a 4th gen aluminum driveshaft and the 3.23 posi rear. I want good power but I want to keep the car streetable on hi oct. pump gas. I plan on using the hi torque First Injection setup.

 

There's no point boring a brand new block with perfect cylinder walls.

 

Ok, so then 377 or 382?

 

Exactly. I'd go 377. It'd be silly to get an extra....5 cubes by buying a custom 3.8" stroke crank and then need custom pistons as well. .050" additional stroke only gives 5 cubes? Huh...

 

A 3.75" stroke would be cheapest, due to the popularity of the 383. A 3.8" stroke would involve a custom crank and pistons, which wouldn't be cheap. You could find a 3.875" crank on the shelf though, but being less popular it would still cost more than the 3.75".

 

If I seem out of my league here guys it's because I am. This will be my first engine build. I just finished reading/watching the book/video combo Rebuilding The Small-Block Chevy yesterday. I learned a good deal from it. I read elsewhere that the 377 is a high rev motor making most of its power at higher rpms. Is this right? If so would it still make for a good street setup?

 

GM's "383" shortblock uses 4" bore. The 3.80" stroke crank is P/N 12489436, a mere $1,126.31.

Yeah, I think I'd stick with a 3.75" stroke crank and go with 377 cubes for now.

There are two ways to make a Gen I SBC 377: 1) .030"-over 400 block with 3.48" stroke 350 crank, and 2) 4.000" bore and 3.75" stroke (which originally was the 400 stroke) crank.

 

Here's a forged 3.800 in. crank I was looking at from Eagle. There's more info on eagle's site... http://store.summitracing.com/partde...006000&FROM=MG

 

Compare that with the $189 you could spend on a cast steel 3.75" crank.

Don't forget that you need to compare the price of the pistons as well.

 

What hp range is a cast crank good up to?

 

More than you'd probably want to drive on the street anyway.

 

The reason I ask is that while I don't plan on running any power adders or nos I was thinking about building the motor all forged to leave that option open in the future.

 

I am torn between going forged and keeping my wallet full though... How about the cam? A roller cam would be the way to go and be compatable with this block right? Also, what is a good streetable rpm range on a cam? The guy at Comp Cams recommend a custom grind that has a 2500-6000 rpm range. After reading some more stuff I suspect that may be a bit to high...

 

With the right parts you can spin a hydraulic roller cam to 7000+ rpm.

 

Hydraulic roller to 7000RPM?!? Which parts do you figure? Rev kit? Crazy springs? I'd do a solid if your goal is to hit 7000RPM.
But lets be realistic with the guy, a 1500-6000RPM hydraulic roller would probably be your best bet. The XR276 or that kind of ballpark. You're not re-inventing the wheel here, so I don't really think you need a custom grind.
I don't think you need forged stuff. That's more for forced induction. You can run up to a 150HP shot of nitrous on a hyper piston and still sleep well at night (IMHO). A cast *steel* crank should be fine up to ~500HP, or about 6000RPM. I wouldn't think you'd need more then that.
If you dyno it at over 375RWHP, and you STILL want more HP, see a psychologist, then worry about re-purchasing bottom end parts.

 

Thanks for the post sonix. I was looking to build something with around a 450 hp max output so putting down 375 actual rear wheel horses would suit me just fine. Glad to hear that about the crank, I think I may just go the cheaper route... If I use hypereutectic pistons it would be best to use flat top ones right? Also, what is your take on this camshaft: http://store.summitracing.com/partde...06%2D8&FROM=MG Would the 2000rpms still be a little much for the street. Should I try and shoot for a range closer to 1500rpms?

 

Use whatever pistons you need to get the right CR for your goals. Flat tops at 76cc heads might work. Or reverse dome and 64cc or something. Run the numbers through a calculator before you buy anything of course.
That cam sounded very similar....
https://www.thirdgen.org/forums/tech...lum-heads.html
I knew I had heard those specs recently.
See if you can gleam any info from that post.

 

7k with an HR cam is a bunch but can be done. I believe beehive springs are the key here.

An rpm range starting at 2000 really isn't that bad, as long as you have a decent converter. That said, a 2500 converter is NOT a lot on the street.

 

Thanks for the replies guys. I was on the summit tech line today and I come to find out that the block actually has a 4.005 in. bore. Is this going to be a problem if I choose pistons that have 4.000 in. bore?

Also, what is your opinion on this cam? http://store.summitracing.com/partde...D50143&FROM=MG