Discussion Forum - Northstar Chevelle Club

4-door Chevelle · Super Poster

Another engine

67ss · 1K+ Club

Find out what piston number they used and go on kieth blacks site to see what they show for rough compression ratio with your 72cc heads. But based on what he says for compression it looks like they uses KB 197 which states 9.1 with 76 cc so with 72 cc maybe it would be around 9.5 which is perfect for a street engine. But also kieth black does not make forged pistons under that name they are all hyperutectic. I would be curious to find out what connecting rod length they used, is it short rod 400 or long rod 350. Seems funny it has no cam specs either in my opinion.

4-door Chevelle · Super Poster

Below are his responses but my big question is will this engine get me in the 12's like a good 383 Stroker should?!?

The rotating assembly from summit description lists 350 length rods and forged dished Pistons to keep compression under 11to1

I found paperwork on eagle kit and yes hyperutectic pistons with 12.00 cc dish and forged 5140 rods-sorry I confused forged rods for Pistons

67ss · 1K+ Club

Well that is kind of a loaded question Darren. Could it get your car in the 12's probably, with enough camshaft, stall, and rear end gear. Does this mean the car is going to still be street friendly, hard to say. You can have a 500 horse motor with 2.73 gears and a 1800 stall and it is not going to run worth a crap. I know your car is not this way but just going to an extream here.

Did he give you any cam specs of what is in the motor at this point? I don't remember are the heads you have aluminum? It could be a good short block to start with, you could angle mill your heads to bring head cc down and raise compression some if your heads are aluminum. Then spec a camshaft to match your stall and rear end gear and have a good combo that can run real strong. Is this all going to get done in a weekend so you can go racing not likely if you want to do it all correctly.

This is just my 2 cents.

4-door Chevelle · Super Poster

Some more detail on the engine:

Heads may be the 462 variety, cast iron

Cam is Edelbrock Performer 7102, Hydraulic Flat Tappet, Advertised Duration 308/318, Lift .488/.510

I am currently running a TH350 with B&M Transpack shift kit, Hughes 3000 stall convertor, 3.73 rear gears with Eaton posi and 26" slicks

If I did this engine I would drop it in and go. I just feel like it would run a little lean with a Edelbrock Performer intake and Edelbrock 600 carb

67ss · 1K+ Club

That combination of parts should work together well. Yes I would agree the intake and carb choice are probably not ideal for the rest of the engine and may limit peak RPM. What do you have for intake and carb from your old motor? Could you swap them over before dropping it in?

4-door Chevelle · Super Poster

I do have a good Edelbrock Performer RPM Air Gap and Holley 670 Street Avenger but my only concern again is the small intake runners in those heads, about 150 to 160!?! I am not sure if they have been worked or not to open them up but I will ask again tomorrow night when I see him.

67ss · 1K+ Club

Yes the smaller port will limit the motor some, but a smaller port typically makes more low end torque. Does he have any dyno papers? A 180-190 port head would be a better match. Guess you have to look at it that you are buying a nice short block and upgrade the top end at a later time. Sell off extra parts to pay for some bigger heads later.

4-door Chevelle · Super Poster

He never did dyno it but we are going for a ride tomorrow night which should tell me what I want to know. I think these heads are somewhat sought after and I should be able to get some cash for them as they are rebuilt and ready to go. My heads are ready to go as well so thank you for your previous comments.