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



At 19:36 2006-02-01, you wrote:

Well, I'm not ready to agree with that conclusion yet. And who say's we need to keep the cooling system stock?

Mike

Ed Anderson <eanderson@carolina.rr.com> wrote:

Thanks for your assessment, Monty.

 

Scares me a bit that we all (more or less) agree that the NPG is probably not well suited to the stock rotary coolant system {:>)

 

Ed

----- Original Message -----

From: M Roberts

To: Rotary motors in aircraft

Sent: Wednesday, February 01, 2006 8:35 PM

Subject: [FlyRotary] sutability of NPG for rotary engine use

<<<  snip   >>>

In short:

 

The 13b was developed to use water/glycol as a coolant.

 

To properly validate NPG you need a dyno and a lot of thermocouples, plus a way to measure the mass flow of the coolant, pressure drops, pump power, and the heat transfer coefficient.

 

Anybody got that laying around in their hangar?

 

Do you want to be a guinea pig?

 

I would not use NPG.

 

Monty