Question on cast crank balancing

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mshred

mshred

The Green Manalishi
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Hey guys,

i have a 360 roller motor that i picked up and would like to build as cheaply as possible, thinking that i could reuse the stock cast crank, Eagle SIR rods (on sale at mancini for 99 bucks!) and some forged pistons to get the compression up as well as be able to take some spray in the late future...in all this though, i would really like to get everything internal balanced in case i ever decide to change to an aluminum flywheel, plus my current flywheel is internal balance as well

my question is, would getting the external cast crank balanced to internal require so much mallory metal that im just better off cost wise to buy a brand new internal balance crank? i know mallory metal is expensive, so if it doesnt make sense to do it, i would just buy a new crank...in fact, if im going to buy a new crank, a stroker may be an option, although im not sure if i would need different rods or what the piston selection would be like for the compression ratio id like to achieve...

anyways, before i get even more away from the original question, please share your opinions on this...i know every machine shop charges differently, but im just trying to get a rough idea

thanks!
Matthew
 
I ran a Mopar cast crank in my 416 which was internally balanced cost me $250.00 to have it done..
 
No, it's not too expensive to get it done. The shop I use charges 200 flat fee plus mallory metal. You should be able to get it done reasonable.....BUT the cost of the Eagle cast steel cranks are around 275. I would keep that in mind.
 
do they always need to use mallory? I've seen them internally balance them by drilling the counterweights. Maybe I'm wrong?
 
whether the crank need mallory metal or not depends on the weight of the rod and pistons compared to the counter weights on the crank...

lighter pistons and rods less the counterweight of the crank needs to weight...

cast crank are lighter sense the metal is not as dense as a forged crank...hence the reason cast cranks either are exteranally balanced or require mallory metal...
 
StrokerScamp said:
No, it's not too expensive to get it done. The shop I use charges 200 flat fee plus mallory metal. You should be able to get it done reasonable.....BUT the cost of the Eagle cast steel cranks are around 275. I would keep that in mind.
Click to expand...

this is exactly how im thinking...if its going to cost that much, then maybe i should just bite the bullet and buy a new peice...i havent heard much good about the eagle stuff though, atleast from what ive heard others say (no experience myself)
 
stroked 340 said:
I ran a Mopar cast crank in my 416 which was internally balanced cost me $250.00 to have it done..
Click to expand...

who makes the mopar crank? sorry, im a bit confused..it was already internally balanced, or you bought it external and had to get it internal balanced, and that balancing cost 250?
 
70aarcuda said:
whether the crank need mallory metal or not depends on the weight of the rod and pistons compared to the counter weights on the crank...

lighter pistons and rods less the counterweight of the crank needs to weight...

cast crank are lighter sense the metal is not as dense as a forged crank...hence the reason cast cranks either are exteranally balanced or require mallory metal...
Click to expand...

this is good info..thanks!
 
I have scat i beam rods and kb 107 pistons with a stock cast crank in my 360, the machine shop said i was going to need 5 pieces of mallory to internally balance it so i ended of having it externally balanced because the cost would be way to high.
 
no...i have not bought from them...

I was going to order a kit..but i got a very good deal on 408 pistons...so it looks like i will be buying it in pieces.
 
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