Calling All Engine Balance Guru's

[plumcrazy 101]

Since the machine shops in my area haven't done this before, or don't have the knowledge to answer, I have to ask the question.

What would the Bob Weight have to be to balance an LA 360 externally balanced crankshaft internally without using Mallory metal?

The Bob Weight on the pieces I have currently and hope to use is 1890 grams.

 

[mischiefdart]

I would doubt it is possible. The cast 360 crank is not as dense as a forged 340 crank so the counter weights are lighter. What is the bob weight of the stock parts?

 

[plumcrazy 101]

The Bob Weight on the last 360 was 2165 grams.
Speed Pro H116 pistons and stock bushed rods with polished side beams( 736 grams)

 

[70aarcuda]

Dont know the bob weight...but one 360 I have has light weight ross pistons...tool steel pins that weight 80 grams...and scat I beams at 585 grams...still would not internally balance with out mallory metal.

 

[skrews]

Stock stroke Eagle cast crank will internally balance.

 

[moper]

All depends on the crank. I haven't tried it - but I'd expect you need an uber-light rod.
Is there a reason there's a fear of Mallory? If you've already got a lighter assembly it wouldnt take much.

 

[plumcrazy 101]

All depends on the crank. I haven't tried it - but I'd expect you need an uber-light rod.
Is there a reason there's a fear of Mallory? If you've already got a lighter assembly it wouldnt take much.

Thanks for all the reply and PM's

No fear of Mallory metal, just a cost thing, and yes we plan using a Scat Pro Comp I beam rod at 569 grams.

As for the Eagle crank mentioned above, we were aware of that option along with the Scat 9000 series crank that will balance internally.

 

[moper]

Well, Mallory is pricy, but in the big picture, meanig the entire budget, it's nothing. I commend you for at least in my opinion "doing it right" too. I only internally balance. It is more money, but you get feelable and visible return.