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Re: [FlyRotary] NPG has been used successfully-Ken
Welter'
Yes I used NPG for several
hundred hrs and it seemed to work fine but I switched back to 60
percent Sierra 40 water mix do to the availability and my concerns of
the viscosity in the sub zero temps that I fly in, the main concern
was possibly over stressing the belts when it was thick and hot spots
do to slow fluid flow.
I first 300 hrs flying used the
Sierra blend and then switch to the NPG for about 300 hrs and then
switched back and I found that there was no noticeable
temperature/cooling differences between the two.
Yes Rob Golden swears by NPG and he
was the one that turned me onto it in my early days of flying when I
was having cooling problems but he then also had concerns about the
viscosity at high attitudes and cold temps so I them switched
back.
Ken Welter
Just one more data point. Al Wick
asked if there was anyone else that had used NPG besides Dave
Leonard.
I recall Ken Welter (rotary powered Coot amphib.) used NPG several
years ago. He had no complaints about its cooling ability and he
was running an old Ross redrive at 3.17:1 (no, not 2.17) making LOTS
of horsepower. He said (IIRC) the only reason he went back to EG
& water was that if you ended up doing some field repair work on
your bird you can not just throw in some water in the mix to make it
home. NPG is supposed to be run at 100% with as much water
removed as possible before pouring it in. (Note: I understand
this is not the case with NPG+)
The real problem with NPG in our rotary powered birds is you can't
walk into any auto parts / wal-mart / seven-11 to get an extra gallon
of the stuff to get you home. You can find EG or just water
anywhere.
One more data point while I'm here. Rob Golden of Pineapple
racing in Portland Oregon swears by the stuff. Rob has been
rebuilding and racing rotaries very successfully for over 30 years.
I have not talked to him in over a year but he used to send every
engine out with only NPG and I believe he required it for the
warranty. Now of course he sells the stuff so there is that bias
on the fly in the ointment.
Neither of these above points addresses the super cooling issue that
in theory seems to be able to turn NPG in the radiator to jelly.
Once again we are left to do a thorough test. Those of us like
Dave who like the idea of flying into high cold places like Mammoth
Lakes to go skiing (sorry Dave..boarding) P-)
may need to plan on a winterization kit like they use in the great
white north, i.e. duc-tape over the cowl inlets.
Okay, I've rambled on enough. Talk amongst yourselves....
Mike
Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
13B in gestation mode, RD-1C, EC-2
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