<VV> Re: Harmonic Balancer Y or N?

[Padgett]

>If the purpose of the unit is to provide external balancing to a cheaply
>assembled mass production engine that inherently is balanced by its
>opposed piston design, wouldn't this be compensated for by custom
>assembling a carefully balanced engine like most of us have?

Folks: if all you had to worry about was the primary vibration on an engine 
then the engineers could go home, an opposed six cyl engine can be 
statically balanced.

However there are secondary vibration that occurs because the crank bends a 
little every time a cylinder fires (and more with detonation) and those are 
not balanced, and a number of harmonic vibrations that usually peak at 
higher speeds. Further at certain frequencies (rpm) these vibrations become 
additive and can increase the stress on the crank many times.

(anyone know what those frequencies are for a Corvair engine ?)

The purpose of the balancer is to cancel those internal vibrations so that 
they cannot build to the point that the stress level of the crank is 
exceeded. If you never run at those rpms then you will probably never need 
a dampner. I put a Dale rebuilt on my 110 shortly after I bought it.

Padgett.