Engine balancing

[SloGN]

Guys


What is the best way to balance my rotating assembly? Should i go with 36.6% or 50%.

My rotating assembly consists of stroker crank, K1`Rods, diamond pistons.


I spun the crank in both %'s @ 36.6 it's telling me to remove a ton of material in the front and back counterweights. using a 7/8 drill bit the hole would be somewhere @ 2 inchs deep.

When i spin the crank in the 50% i had to change my bob weight of course.but It's telling me i need to remove weight in a area where the crank pin radius are. I surely can't remove weight there.


What should i do?

TIA Pat Broughton

 

[nolag]

36.6 if mainly a street car, the other is mainly race.

 

[charlief1]

A 50% will help the engine live better but cause vibrations in both planes and the 36.6% will reduce one plane while increasing the second. You don't remove weight from the crank pins for a 50%, you add it to the counter weights with Mallory.

 

[turbodave231]

I've done race engines both 36.6 and 50%. I can't tell the difference in vibration.

It will be easier to balance using the 36.6 factor.....less mallory. If the balancer calls for alot of metal removal in one spot, some balancers will allow you to split that amount into two locations. All material is removed from /added to the front or rear counterweights.

Dave

Dave

 

[SloGN]

When i spun the crank on the machine i had just the crank and the bob weights attached to bit.

Do i need to attach the balancer and flexplate to it too? I'm using a BHJ balancer/dampener and a stock flexplate thats in the process of being nuetral balanced.


should i just wait and balance the complete after get get my flexplate nuetral balanced. or can i just spin the crank. then reinstall the flexplate and spin again to verify that i did indeed get my flexplate nuetral balanced.




TIA patrick broughton
(motor mouth)

 

[charlief1]

When i spun the crank on the machine i had just the crank and the bob weights attached to bit.

Do i need to attach the balancer and flexplate to it too? I'm using a BHJ balancer/dampener and a stock flexplate thats in the process of being nuetral balanced.

should i just wait and balance the complete after get get my flexplate nuetral balanced. or can i just spin the crank. then reinstall the flexplate and spin again to verify that i did indeed get my flexplate nuetral balanced.

TIA patrick broughton
(motor mouth)

I think we have an answer to your problem. Yes the balancer/dampner need to be attached as well as the flexplate.

 

[V6gofast]

I think we have an answer to your problem. Yes the balancer/dampner need to be attached as well as the flexplate.

If the balancer/flywheel are neutral it isn't going to make any difference on
the crank. For the record I use 36.6% on anything under 800 or so HP.I have
done several 1300 +HP engines also at 36.6 and not seen any Ill efects.
If you are going to use the lesser value I would suggest taking a cut off the
counterweights in a lathe ,it makes for a much nicer job.

 

[SloGN]

If the balancer/flywheel are neutral it isn't going to make any difference on
the crank. For the record I use 36.6% on anything under 800 or so HP.I have
done several 1300 +HP engines also at 36.6 and not seen any Ill efects.
If you are going to use the lesser value I would suggest taking a cut off the
counterweights in a lathe ,it makes for a much nicer job.

Dan

Thanks for the great info! Will you do the balancing on my assembly for me? I don't have a lathe to do what your talking about. i'm also a novice at using the crank balancer aswell. I didn't think i needed to have the balancer/dampner and flexplate on the assembly since those are nuetral balanced. the dampner is a BHJ unit and the flex plate is a stock one that has been modified.

My pistons and rods have alreadly been balanced and I also know the weights of all my other componets.

 

[V6gofast]

If you want to send it up here we can take care of that , it's just part of our
normal service.