what size balancer?

[HAM1974]

i am building a 350 with 40 over pistons,5.7 rods. what size balancer do i need? looking in jegs,summit they have 2 or3 diffrent sizes 6-3/4 to 8". what is the diffrence between these and which one would work best for limited street use and maybe a couple of trips to the track?

[jsbhemi]

What I understand the larger diameter balancers do a better job of dampening vibrations, on the other hand die hard hp enthusiasts go with smaller diameter balancers to reduce the rotational mass, hence freeing up horsepower. I don't think you will see huge gains switching from an 8 inch to a 6.75 inch balancer, but what do I know.

[chris1972]

go with the larger one for street used because will help with vibrations make sure to get right on they make ext bal..and ext bal

[Ryoung68]

make that ext bal..and int bal

[spacecadet]

If you were only strip use, the small one but for the street use the big one. You want that motor to run as smooth as possible.

[stevo67]

For street/limited strip use, replace the Balancer with the same size as what came on it originally. If it had an 8", use and 8". If it came with a 6.75", use a 6.75", etc.

More importantly though, take those rods and your new pistons and have them balanced, along with the crank, before assembling the motor.

This is another reason that race only motors can get away with a smaller Balancer, they are internally balanced to MUCH tighter tolorances.

Factory assembled motors went to the bigger Balancer because it allowed them to "skimp" on the labor cost of assembling thousands of motors, by reducing the "balance tolorance" of the engines. A few extra Grams became "good enough", with the larger diameter Balancer.

[chris1972]

For street/limited strip use, replace the Balancer with the same size as what came on it originally. If it had an 8", use and 8". If it came with a 6.75", use a 6.75", etc.

More importantly though, take those rods and your new pistons and have them balanced, along with the crank, before assembling the motor.

This is another reason that race only motors can get away with a smaller Balancer, they are internally balanced to MUCH tighter tolorances.

Factory assembled motors went to the bigger Balancer because it allowed them to "skimp" on the labor cost of assembling thousands of motors, by reducing the "balance tolorance" of the engines. A few extra Grams became "good enough", with the larger diameter Balancer.

i agree what stevo said have it blanced