> I'm not that engineer nor do I have his ability but I can say
> with a good deal of certainty that there is no engineering for vibration
> dampening or tuning associated with those rubber pieces or the
> way they are
> installed.
Well, I'll certainly agree they weren't designed to the same level as
NASCAR. But neither was anything else on our TRactor motors ! You
mentioned once that you have the "blob of metal" damper hanging on the OD
tail housing ... does it look 'tuned' to you ?
> If they provide any dampening it's by accident in my opinion.
Try ringing a cymbal sometime, then touching it with your finger. Your
finger wasn't designed to NASCAR standards either, but it will very
effectively stop a cymbal from ringing.
> They may eliminate some vibration associated with the fan itself but in no
> way do they tune out any crank vibrations.
I propose an experiment. Lets suspend a crank so it can be 'rung' (they
don't ring as well as a cymbal, but a healthy crank will definitely ring ...
this is an old timer's trick for checking for cracks), then mount a fan on
it. How much will you bet that it will ring as much with a fan & rubber
mounts on it ?
> I've not seen those
> statements that you
> have seen and I'd welcome a reference to those who have stated
> what you have
> repeated.
I'm pretty sure I first heard it from Ken Gillanders, but I could be
mistaken. If I should manage to run out of better things to do, I'll look
for the note from the factory.
> There is opinion and then there is fact.
Yes indeed.
> I'm stating my
> opinion on
> this subject and will admit to being wrong if I could see some credible
> evidence that those grommets are designed as crank vibration dampeners.
I'm not saying you're wrong, Jerry, just asking why you hold the opinion you
stated. I won't even claim they were designed as dampers ... as I recall
the statement was that they _act_ as dampers.
> I know of racers who use MGB dampers and I suppose something is
> better than nothing.
FWIW, I squirreled away a long-ago post from Hardy Prentice saying that his
crank life (using factory cranks) went up noticeably after using a damper.
But he admitted to turning over 7k rpm, on a race-prepared factory crank.
Unfortunately, didn't say much about what damper he used.
> I like your idea about an underhood temperature thermostat. I wonder where
> one of those could be found. Any ideas?
When I bought the electric fan for my Stag (later removed), the same company
(DeRale) sold an adjustable control relay with a thermocouple pickup that
just poked into the radiator fins, and had an input for AC clutch (to run
the fan any time the AC was on). As I recall, the lower end of the
adjustment was pretty low, like 160F. That might be one source. No reason
the probe couldn't be mounted anywhere you want it, and your radiator switch
could hook into the AC input (or just parallel the relay contacts if you
want).
Here it is, DeRale P/N 16759
http://www.derale.com/electricfanaccess.shtml
Summit has them for under $30
http://store.summitracing.com/partdetail.asp?autofilter=1&part=DER%2D16769
No doubt there are better ways to accomplish the same thing, this is just
one suggestion.
Randall
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