Dick Gregory wrote:

Has anyone tried using Evans NPG coolant? You don't mix water with it and

it

doesn't boil until 370F. Evans recommends 0-7 psi cap since engine

hotspots

won't cause local boiling. They claim no oxidation or corrosion for metal
parts, and histories of hundreds of thousands of miles in trucks.

Just wondering if anyone has positive or negative experience with it.

Dick Gregory
LongEZ N613NC (Soon to be 13B powered)

Ken Welter is running it now and so far so good. However he is not measuring
the temp down near the base of the spark plug so who knows. Unless we start
doing that we will never really know what is going on in our engines cooling
wise. The metal temps are the very bottom line.
The water temp can be anything but who knows what the metal temperature is.

Paul Lamar

"Bass, Jerry" wrote:

Does anyone know where to get the NPG cocktail?

 How about heat pipes.  Can we bolt onto the engine small heat pipes that
would move the hop spots out away from the combustion chamber. Put radiating
fins on the heat pipes to convect the heat away.
Jerry Bass

I would use caution on this. I would install thermocouples  near
the combustion chamber before I used it. There are a lot of issues
in regard to using NPG. You could crack or warp your rotor housings.
Boiling temperature alone is not necessarily the bottom line.

http://www.evanscooling.com

Paul Lamar

This has been covered before, but we have many new members and
this is worth repeating.

                Local boiling of coolant is NOT bad.

Phase change has an order of magnitude higher heat transfer than single
phase heat transfer.  This can be very important when you have a
local hot spot.  The coolant will locally boil, and assuming adequate
local coolant flow rates to carry away the bubbles, and adequate
radiator size and airflow to keep the bulk coolant temp within reasonable
limits and not boiling everwhere, you will keep the hot spot from going
much above the coolant boiling temp (at the coolant side).   If you
raise the boiling temp of the coolant, you raise the local temp of
the metal at the hot spot.  Good chance that the *coolant-side surface*
of a motor will stay pretty close to 225F with 50/50 EG/water and would
probably go up to about 400F with a 370F boiling coolant.   You
would get better heat transfer per unit radiator size with a higher
coolant  temp, but running the metal hotter can't be good.

100% ethylene glycol cools WORSE than 50/50 EG/water mix.

There is a LOT of snake oil out there.   I am not saying that NPG is
snake oil, really haven't looked into it, but it is likely not optimum for
cooling engines designed for EG/water 50/50 mix.

Bill Freeman

Take another look at all the charts on this subject I have uploaded 
recently.

Paul Lamar
 
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