[TR] T3/4, fan,extension

TeriAnn J. Wakeman tjwakeman at gmail.com
Tue Dec 11 17:00:16 MST 2012

On 12/11/12 1:54 PM, David B. Hammond wrote:
> I have removed the mechanical fan and extension. I have heard of the need to
> install a harmonic balancer, but I don't know why? Any discussion about
> that?
> David
> TR3B
If you keep the engine revs below the 5000 RPM redline there is no 
reason th install a harmonic dampener.  However there is a harmonic in 
the crank at around 5200 RPM that is breached too often tends to crack 
the crank at the base of the flywheel mounting flange.  The harmonic 
dampener is meant to tame that harmonic.

If you use your 3 as a street driver and touring vehicle the mechanical 
fan is a good thing to have.  If you do some auto crossing a harmonic 
dampener is insurance for those times you are looking at that upcoming 
cone and not the tach.  If you intend to autocross on a regular basis, 
do hill climbs & the like you want to get the crank nitrided as well.  
The next big harmonic is above 6000 RPM and tends to break the crank in 
the middle.

I guess I should have asked why you removed the mechanical fan & 
extension in the first place.


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