Mailing List flyrotary@lancaironline.net Message #7922
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: MPG Coolant
Date: Sat, 8 May 2004 14:09:59 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
If you are running 290F on your rotary, then the last thing you are going to
have to worry about is the coolant boiling. Your engine is going to have
cooked the seals!  Most reciprocating engines can stand higher temps than
the rotary so it may have some marginal benefit for them.  The other thing
you need to check is the specific heat for that coolant.  NOTHING (that I
have seen that we have access to), but NOTHING beats pure H20 for
transferring heat from engine to radiators.  Even using a 50/50 normal
anti-freeze/water mix reduces the heat carrying capacity of water by almost
40%.  Remember boiling point tells you almost nothing about the heat
carrying capacity of a liquid only the temperature where the liquid phase
shifts from liquid to vapor.

Now if you have pets around, then the Non-toxic aspects may be worth it.
But, I think most of us who have been flying several hundred hours with our
rotaries would tell you there is no need.  But, if you are going to, then
check the specific heat for as you reduce the heat carrying capacity (which
is not the same as boiling point) you need to flow more coolant to get the
same heat removal from the engine.

FWIW

Ed

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From: "Steve Brooks" <steve@tsisp.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Saturday, May 08, 2004 1:38 PM
Subject: [FlyRotary] Re: MPG Coolant


> Dave,
> I did a search on the web, and the MPG coolant is Mono Propylene Glycol.
It
> is the non-toxic anti-freeze, and apparently it does have a much higher
> boiling point.  Both Sierra and Amsol make one.  After reading about it,
I'm
> definitely going to get some.
>
> Steve Brooks
> Cozy MKIV 13BT
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
> Behalf Of daveleonard@cox.net
> Sent: Saturday, May 08, 2004 12:44 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] MPG Coolant
>
>
> One of the guys at the airport says that "all" the subaru guys are using
> something called MPG instead of Ethylene Glycol/water because it boils at
> 290 without need to be pressurized.
>
> Does anyone know anything about that stuff?
>
> Dave Leonard
>
>
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