<VV> Re: [FC] [VV] Harmonic balancers....

[BobHelt at aol.com]

Rick, please see below. 
Regards.
Bob Helt
 
In a message dated 6/30/2007 9:15:00 AM US Mountain Standard Time,  
ral1963 at comcast.net writes:

Has any  thought been applied to using or not using HB on larger than
164cu  motors?
 
Depends on who is asked.



Was it the longer throw of the stroked motor that required the  HB?
That is part of it. It really is based on the fundamental frequency of  
oscillation of the crank (222 Hz for a stock 8409). This is dependent on  many 
factors. Then as Lon points out it is also based on the strength of impact  too (f
orce of the piston on the power stroke). Plus of course the frequency of  the 
incoming power strokes that coincide with the crank's natural frequency  
causing a build up of oscillations until a crack is developed/expanded/causes  
failure. (remember the Memorex glass breaking?)
 
 Set a crank on end or suspend from a wire and gently tap it with a  hammer. 
You will hear a  ringing sound which is the crank vibrating at its  
fundamental freq. But as with all vibrating objects, there will be oscillation  nodes 
and these result in vibration harmonics. Study sounds from  piano wires for more 
info.



If you stroke a 164 motor, will the stock HB still function?  Would the
harmonic's and damping effects still cancel themselves  out?
 
Most likely you will require a new HD based on the new crankshaft. The  stock 
HD is likely insufficient to protect the stroked 8409 crank.
 
Regards,
Bob Helt
 



Rick Loving






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