> > Tom,  I bought both the rad and the fan from Summit.  I tried to buy
 > > the rad with AN fittings  and no filler but they wanted nearly
 > > $200.00 more for the " special order" so I bought the stock unit
 > > which I will modify myself.  The rad cost $279.99 and the fan was
 > > $179.00.   The rad and fan both are intended for racing applications.
 > > I tried to deal directly with Griffin but they apparently no longer
 > > are doing this.  They gave technical advice and then told me to order
 > > it through a dealer.  Jerry

 marc wiese wrote:

 What about the concern that at 200mph your fans will be spinning like a top
 and eating up those fan bearings? It would be a bad day if a fan came loose
 because of it. Check those fans often!
 It seems if you had fans, you would want them in a duct you could close off
 and open only when you needed the air.
 Marc

In a properly designed duct near the rad face the air should not be
moving that fast. Probably only about 30 to 50 mph. Still enough
to spin the fans however and cause bearing failure. It happened
to a guy out in Camarillo CA with a water cooled V8 pusher.

Cooling air, after entering the  entering the rad intake is in a
constantly expanding plenum and is really slowing down.  On the exit
side of the rad, the air is dumping into the entire volume area of
the fuselage and should loose even more momentum.  The outlets are
much larger than the inlet.  I don't think the air will possess much
energy.  I have an electric fan on my RX-7 that I suppose is free
wheeling.  It is not hooked up so it never runs.  The bearings were
o.k. a couple of weeks ago (160,000 miles) when I was contemplating
stealing it for the airplane.  Also, I think the low energy, slow
moving  exiting air will have no problem finding its way past the fan
which is something someone else brought up.  Having a big plenum and
large exhausts is one of the benefits (to go along with a host of
head aches)  of the fuselage installation.   Jerry

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