440 motor internally or externally balanced

[Ralph Cali]

All, how would I determine if I have an internally or externally balanced motor. It is a 12/1972 date coded 440 block for 1973 car. It was rebuilt by an engine builder with a 4340 forged steel stroker crank making it a 522 cubic inch.
I am going to replace the flywheel and not sure what to buy.

Any advise welcome

Ralph

 

[70rr-brian]

Generally speaking if it has a forged crank in it one would expect it to be internally balanced. I would further suspect internal balancing if it was stroked. But that engine from the factory with that cast date likely came with a cast crank and was externally balanced. How thick is the harmonic balancer?

 

[67 B-body]

All, how would I determine if I have an internally or externally balanced motor. It is a 12/1972 date coded 440 block for 1973 car. It was rebuilt by an engine builder with a 4340 forged steel stroker crank making it a 522 cubic inch.
I am going to replace the flywheel and not sure what to buy.

Any advise welcome

Ralph

I dont know of anyone producing 4340 steel crankshafts in an externaly balanced version.

 

[Ralph Cali]

Brain, I checked the balancer and it was about 1 to 1 1/4" thick

 

[Meep-Meep]

Externally balanced engines will have a significant weight placed off center on the harmonic absorber and flywheel. If your flywheel just has the normal drill pecks in a couple of places then it might be safe to say it's internally balanced. I am also unaware of any 4340 cranks requiring external balancing.

 

[70rr-brian]

Yeah I'd bet pretty much anything its internal balanced.

 

[Ralph Cali]

thanks to all

I plan on buying a new 143 tooth flywheel for the car and then I would be purchasing one that is for internal balance

Is that a zero balance ?

Ralph

 

[70rr-brian]

Neutral balanced is the term you are looking for.

 

[Meep-Meep]

Neutral balanced is the term you are looking for.

Yeah, zero balance or neutral balance is the same thing. Basically no mass off center anywhere.

 

[Ralph Cali]

thanks to all

Ralph