<VV> harmonic balancer

[RoboMan91324 at aol.com]

Chris,

First, harmonic balancers (HB) can and do fail.  Think of the assembly as a 
disk surrounded by a ring.  In the small gap between the disk and ring is a 
pliable material that permits them to vibrate.  With age, the material can harden 
and or separate causing the ring and disk to rotate independent of each other 
and, in some cases, the ring moves to the point where it grinds on the oil 
filter causing you to lose oil all over your engine compartment.  It can also 
cause your fan belt to fly off.  There is a mark that you can see on both the 
ring and disk that should align.  If they are not aligned, you have slippage and 
should replace the balancer before something catastrophic happens.  Of 
course, this doesn't hold true for the solid pulley.  You can have your HB rebuilt.

Second, what it does ....... Like most objects, the crankshaft in your 
Corvair has a frequency at which it likes to vibrate.  This is called its natural 
frequency.  Actually, since it is a complicated structure with pistons and con 
rods hanging off of it, it has a number of frequencies.  In the 164 CI engines 
(1964 and later) there is a frequency that feeds on itself at certain engine 
RPMs or what is called a harmonic frequency.  This can create a crack in the 
crankshaft causing it to self destruct.  The purpose of the HB is to counteract 
this harmonic frequency and prevent the premature failure of the crankshaft.  
The HB is designed to vibrate at a frequency to interrupt the most destructive 
frequency of the crankshaft.

I believe that the HBs were used on all 164 CI engines except possibly the 95 
HP.  Personally, I would use a HB on a 95 HP anyway.

Doc
1960 Vette; 1961 Rampside; 1962 Rampside; 1964 Spyder coupe; 1965 Greenbrier; 
1966 Corsa Turbo Coupe; 1967 Nova SS; 1968 Camaro ragtop
~~~~~~~~~~~~~~~~~~~~~~~~
In a message dated 3/29/2009 2:55:56 PM Pacific Daylight Time, 
virtualvairs-request at corvair.org writes:

> Message: 10
> Date: Sun, 29 Mar 2009 14:40:03 -0700 (PDT)
> From: chris mann <cfmann at yahoo.com>
> Subject: <VV> harmonic balancer
> To: "virtualvairs at corvair.org" <virtualvairs at corvair.org>
> Message-ID: <595997.50671.qm at web36805.mail.mud.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
> 
> 
> I know where it goes but am clueless about what it does. Why is it called a 
> harmonic balancer?
> And do they fail or where out?
> Chris mann


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