Ok I have 2 questions for you guys.

I have a 350HO crate engine that I will be tearing apart this winter.

I am going to be building a standard bore 383 (377ci, 4" bore, 3.75" stroke). The motor is a late style 1 piece rear main seal block. Which crankshaft do I need for this motor, the internal balance 1 piece rear main seal or the external balance 1 piece rear main seal?

Also, do you guys think I would be better off with a Scat 9000 series cast crankshaft or an Eagle Cast crankshaft? This motor is going to see some abuse so I want the better of the two.

Seth

 

383's, originally used the 400ci cast cranks which were externally balanced. With aftermarket forged cranks you can go either way.

 

These are cast cranks. Is there a benefit to going internally balanced as opposed to externally balanced?

 

I believe it's a matter of cost. Don't think one is "better" than the other.
To make an externally balanced crank internally balanced you have to add expensive heavy metal (and no not the band) to it.

 

I would pick up a Scat 9000 crank, that is 1 piece rear main internally balanced. It will need some heavy metal with 5.7" rods but it will stress the crankshaft less since it's internally balanced.

Vizzard wrote a good article in Pop Hod Rodding about harmonics in strokers and the basic point is that internal balance is better for harmonics than external balance. Check back at last months issue or so.

Bret

 

Thanks!