<VV> Harmonic Balancer

[kevin nash]

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 cant 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!!