[Tyroma]

Hello all..

All you hardcore engine guys...get your slide-rules out and please tell me what kind of power I can expect from my upcoming build. Here's the poop on the engine...

.30 over 350 block
11.8:1 pistons
Edelbrock Performer RPM heads (70cc cham, 2.02/1.65)
Holley Street Dominator Alum intake
750 cfm Q-jet
Hedman headers
Crane 1.5" full roller rocker arms
Crane .480/480 cam and lifter set
gear-drive timing setup

Trans...

Rebuilt 350 with Trans Go kit

Axle...

4:10's with a Eaton posi

Along with some estimates, any horsepower adding suggestions would be great!

Thanks!

Ty

 

[big454blockchevy]

I say 350-380 hp

 

[MIKEWITH THE 81'S]

Well I'm no guru, but i would say that your comp ratio is too high. I dont know what you are putting this in (a chevelle i assume) but you can have a fun car if you don't make so much compression that you cant run pump gas. If you would run like 10.25/1 you could drive it on the street. not to mention you wont need a tilton starter to get you going. there are several guys with those heads on the site. ONE guy (kazuki) is running 11.40's with those heads and 11.1, but you're pushing it . Compression does make power but think about drivablility. also try rpm air gap it was designed to be used with those heads or victor jr. You can order vr.jr ported to match those heads out the box. (so i've been told.) I am considering a 406 with the same setup for my every day truck (if I dont go BBC). and I expect 400hp and 500ft.lbs of torque. (REMEMBER TORQUE MOVE OUR BIG OL' HEAVY BOATS, AND HP IS FOR THE BIG END)

 

[Tyroma]

Well I'm no guru, but i would say that your comp ratio is too high. I dont know what you are putting this in (a chevelle i assume) but you can have a fun car if you don't make so much compression that you cant run pump gas. If you would run like 10.25/1 you could drive it on the street. not to mention you wont need a tilton starter to get you going. there are several guys with those heads on the site. ONE guy (kazuki) is running 11.40's with those heads and 11.1, but you're pushing it . Compression does make power but think about drivablility. also try rpm air gap it was designed to be used with those heads or victor jr. You can order vr.jr ported to match those heads out the box. (so i've been told.) I am considering a 406 with the same setup for my every day truck (if I dont go BBC). and I expect 400hp and 500ft.lbs of torque. (REMEMBER TORQUE MOVE OUR BIG OL' HEAVY BOATS, AND HP IS FOR THE BIG END)

Thanks for the info. My reasoning behind the 11+ compression pistons is due to the larger 70cc combustion chambers. It should lower the compression to the mid to high 10's.

Thanks...

Ty

 

[68chevelle533]

Most of the pistons list a CR with a certain CC head. From there you can work the numbers to calculate the compression for a different CC head. It is better than guessing. It is not hard to make over 400 streetable hp with those heads. I would pick your parts to match what you want the engine to do and let the hp numbers fall where they may. IMO you will be happier with the results. What are the duration at .50 numbers on your cam, it tells more than the lift does.