<VV> Harmonic Balancer

Wed Jul 19 10:30:15 EDT 2006

While I agree completely in theory; there is a pratical side to the harmonic damper question.
I have had and witnessed others also having huge engine failures when the damper came apart , and cut the oil filter. The first time that this happened to me, I started running the 95 HP solid pulleys, without failure--YET.
   As I understand it, the harmonic resonant frequency is around 4500 rpm, which is about 90 mph in most Corvairs. Autocrossers would pass through this area rather quickly and road racers should always be above it.
  It is also my belief -unsubstantiated of course, that the real harmonic balancer is on the other end of the crankshaft--the special only to Corvairs flywheel. I have witnessed (i.e. Black hawk Farms track event ) crank failures of racers with rubber dampers, and fluid dampers. What these racers had in common was replacement of the "real damper" with very small, very light, solid flywheels.
   I've been running aluminum crank pulleys for years now; in order to obtain proper (slower) fan speed and lessen belt throwing with no crank problems.
   OK, now I've done it, I'll probably break a crank this weekend.
  During GM's embarrassing cost cutting period when engines had cast iron cranks and no internal balancing, or purposely unbalanced engines, external balancers and counterweighted flywheels were absolutely necessary.

Warren

-----Original Message-----
From: kaczmarek at charter.net
To: vairologist at verizon.net; virtualvairs at corvair.org
Sent: Tue, 18 Jul 2006 9:45 PM
Subject: Re: <VV> Harmonic Balancer

Folks 
Subject: <VV> Harmonic Balancer 
I know this one wasn't Convention related, but it is related to my line of business. 

1st, Let me give my friend Smitty an "AMEN". I heard the story first hand at a club meeting after it happened, and then in the Communique afterwards. That true saga of his Breakdown on the Great Plains (to call it a story is really doing it a dis-service) is without a doubt a "Hard Luck Story for the Ages". I doubt myself smart enough to figure out the things he did, and I don't have his mechanical aptitude. But if I had to go thru what he did on that one trip, I don't think I'd be involved with Corvairs anymore. 

2nd, I want to say that Smitty's historical summary of the why's and wherefores of the Harmonic vibration problem is spot on. I listened to 2 SAE engineers discuss this at a show in Florida recently. Smitty might not be an engineer, but he's sure got a tight hold on this issue. But after knowing him for 18 years, this is what I have come to expect. I'm glad he gave an overview, but he actually said it all with the first sentence. Good-O Smitty! 

3rd. Cadillacs and Packards in the late 30's had special harmonic balancers. The only thing common to the engines is they're in-line 8 cylinders. As you can see in the Packard listing below, no 6's, 120's(Junior 6's) and one of the engines in the Super 8 Series. 

>From the Steele Rubber Products 2006 Catalog 

Read both the description and the price. Be Happy! 
Vibration damper, crankshaft, front. Revulcanizing service for rubber cushion elements. All models (except Six, 120's, and 1939 Super 8). This includes assemblies #195918, 201075, 210647, 219921. Any parts needing replacement beyond the friction disks, which we will replace if required, will be your responsibility. Most units need only cleaning and revulcanizing. Send us the entire unit. Timing calibrations will be kept intact. Allow 2 to 3 weeks for service. 

IMHO, Get you a balancer, get it rebonded, and put it on, I don't give a hill of beans what the engine, or the Type of Vair it's in. 
Dampening Torsional vibration is never a bad thing. 

Hank  
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