<VV> Harmonic Balancer

[James Davis]

If you look at the initial SAE engineering paper, the 140 cuin Corvair
engine showed a huge crankshaft resonance at around 4,400 rpm, enough to
propagate cracks in the crankshaft.   Thus only the engines with the
ability to sustain operation at and above 4,400 rpm were equipped with a
harmonic balancer initially.
Jim Davis

On Sat, Mar 21, 2020 at 11:32 AM kevin nash via VirtualVairs <
virtualvairs at corvair.org> wrote:

>
>
>
> Message: 4
> Date: Sat, 21 Mar 2020 13:36:26 GMT
> From: "Brian" <bmoneill at juno.com>
> To: VirtualVairs at corvair.org,    fastvair at yahoogroups.com
> Subject: <VV> Harmonic Balancer
> Message-ID: <20200321.093626.14512.7 at webmail09.vgs.untd.com>
> Content-Type: text/plain; charset=windows-1252
>
> Just to take a break from all the carburetor mystery talk, here's today's
> question.  What are the pros and cons of installing a Harmonic Balancer on
> a 145 ci engine?
>
>
>  The only "demonstratable" advantage of installing a Harmonic Balancer on
> a short stroke engine is if you want a crank triggered ignition, and would
> prefer to use a Hall effect sensor. These sensor's rely on a magnet moving
> over them to detect the crank position. A neat, clean and really solid
> location to mount one of these sensors on a Corvair engine is the rear
> accessory cover, essentially "hard mounting" the sensor to the engine.
> Mounted like that, the magnets must be placed on the crank pulley, and
> should be around .080" away from the sensor. The magnets used are long
> enough that the only reasonable way of securely mounting them is to use the
> H/B, and drill close fitting holes on a hole circle. There's not enough
> metal on the stamped steel crank pulleys to do this. Some "theoretical"
> advantages are, that it may be possible to get a slightly nicer dynamic
> balance of the crank/flywheel and pressure plate, and crank pulley assembly
> because some material can be taken off the HB and c
>  ant on the solid one. Also, the HB probably has a truer running v-groove
> that the stamped steel pulley, and because of the torsional damping may
> slightly further reduce crank fatigue. The only reason I run the H/B on
> mine though is because I had to for my ignition set-up, and no other reason.
> Kevin Nash
> 63 Turbo EFI daily driver
> Baddest fan on the planet!!
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are
> the property
> of the writer, please attribute properly. For help, mailto:
> vv-help at corvair.org
> This list sponsored by the Corvair Society of America,
> http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options:
> http://www.vv.corvair.org/mailman/options/virtualvairs
> Archives: http://www.vv.corvair.org/archive.htm
>  _______________________________________________
>