Although technically true in that a 90 degree V-8 has some unresolved harmonics and moments (or couples), it is perfectly balanced in terms of primary and secondary forces - see HERE.

The 60 degree V-8 and 90 degree V-6 configurations require balance shafts to compensate for secondary forces.

Rusty

 

[QUOTE]Originally posted by HOHN
Actually, it technically depends on whether or not the damper/balancer is, in fact, helping to balance the engine. On some externally balanced engines (Cast Crank Mopar 360s come to mind), this device actually performs some balancing (note the offset when viewed from behind).

But on a typical internally balanced engine, this device does NOT balance anything. You are correct that it is there because of crankshaft twisting, but this is to DAMPEN the vibrations, not "balance" them. The only way to "balance" these vibrations would be to have identical harmonics induced that were 180° out of phase and create destructive interference between the two waves.

This is why "balance shafts" are used on some VEE configuration engines. Because a vee is inherently out of balance, the balance shaft is the only way to counteract this effect by doing just as I described above- generating a force equal and opposite to cancel out the primary force.

That said, there's a reason why there are trade names out there like "Fluidampr" (sic) not, "fluidbalancer".

Submitted for your consideration.



Did you come up with all these conclusions on your own????
What is the reason for the trade name "fluidampr"???
You have some interesting theories on balancing engines and the use of a "balance shaft".
The last time I used a damper was on my old wood burning stove in the stove pipe and ther was no vibration in it.
jlh [/QUOTE

 

The following definition is from the American College Dictionary (latest copyright 1966) and, although for an electrical meter, conveys the mechanical sense of the usage of the word:

damper - 4. Elect. an attachment to keep the indicator of a measuring instrument from oscillating excessively, usually a set of vanes in an air space or fluid, or a short-circuited winding in a magnetic field.

Rusty

 

You say potato and I say po tot o, yoy tomato and I say to mot o. Lets call the whole thing off.

 

I'm jus' gonna "mash" the soot petal and go home.

see y'all later.