[DeTomaso] Anyone with Experience with Evans NPG Propylene glycol Coolant

GW gow2 at rc-tech.net
Mon Feb 14 12:32:48 EST 2011

Agreed. With a thermostat controlled cooling system cooling observations 
don't mean anything unless your cooling system can not keep up. That is 
where I was. Going back to regular coolant my cooling system was far 
more able to keep up. While I did not measure input and exit temps the 
difference quantifiable. Also, changes I made were individual one at a 
time changes so I could evaluate each change individually.

I would be concerned about a 260 degree exit temp for normal cars. 
Especially knowing areas of the engine are above that temp. The babbot 
on melts around 350 and I don't think they would be happy at 300.

If it is say a drag racer whose engines are tore down every run, every 
couple runs, may be a different story.

Suffice to say if the cooling system can't keep up it won't keep up with 


Ken Green wrote:
> Gary,
>     If you measure the exit temperature of the coolant it seems like 
> it will always be higher with Evans coolant because about a 60% higher 
> delta temp between entering and leaving the engine is required to 
> remove the same amount of heat.  I think the meaning of engine temp 
> needs to be defined better. 
>     Some of the people posting to forums seem to think 260 deg exit 
> temp for this stuff is fine.  That seams really hot, but they were 
> fine with it.  They seem to think that the temp is not as important as 
> if the coolant is boiling.  There was at least one guy who collected 
> ping data and said the Evans collant made a measurable difference and 
> allowed running a more aggressive advance curve.
>    It appears that Rotax specifies Evans coolant for their aircraft 
> engines:
> http://www.rotaxservice.com/rotax_tips/rotax_feed4.htm
> (near the bottom)
> Ken
> --- On *Mon, 2/14/11, GW /<gow2 at rc-tech.net>/* wrote:
>     From: GW <gow2 at rc-tech.net>
>     Subject: Re: [DeTomaso] Anyone with Experience with Evans NPG
>     Propylene glycol Coolant
>     To: JDeRyke at aol.com
>     Cc: detomaso at realbig.com
>     Date: Monday, February 14, 2011, 4:40 AM
>     I have played with Evans coolant and know some others who have as
>     well.
>     There are some advantages and disadvantages.
>     Advantages
>     1. There is no and can be no water in the system. The boiling
>     point of
>     the fluid is increased dramatically. This is advantages if you
>     have an
>     engine with hot spots. It is good to run an engine in the 190-210
>     degree
>     range. Metallurgy likes it and it keeps moisture out of the oil
>     during
>     operation. However with a water temp of 200, areas in the
>     cylinders are
>     hotter. A hot spot can develop which boils the water and creates a
>     vapor
>     pocket. Once the vapor pocket emerges, the hot spot gets hotter
>     and the
>     vapor pocket gets hotter. This leads to detonation and other.
>     http://www.rc-tech.net/cars2/hs.jpg
>     With Evans and the higher boiling point, there is no hot spot.
>     2. Running Evans coolant, the system is an unpressurized system. I
>     know
>     some one running a radical engine and this has stopped head gasket
>     failures.
>     Disadvantage
>     1. It simply does not cool as well as water and traditional
>     coolant. If
>     you have a more then adequate cooling system, it is no big deal.
>     If your
>     cooling system is borderline it will begin to raise temps when it
>     can't
>     keep up.
>     I tried it for a while in my MG. I was having some cooling issues
>     with a
>     new crate engine and not enough baffling. My thermostat was not
>     keeping
>     up. When I changed from Evans back to traditional coolant I saw a
>     significant drop. My engine was almost able to keep up; at least a 10
>     degree drop over all for the same situations and temps. After
>     putting in
>     an oil cooler I have never had a cooling issue since under any
>     situation.
>     2. If you have problems on the road there is only one fluid you
>     can use
>     as a substitute (I forget which one). You can't use most of the
>     coolants
>     on the market; if you do you wreck the fluid. This can be very
>     inconvenient.
>     3. It's very expensive. If you do ANY cooling system work on the
>     car you
>     will need to find
>     a way to reclaim the fluid. It is too expensive to drain off.
>     4. Here is the worst thing; its flammable! I read about a race
>     some time
>     ago where the driver was severely burned; not by gas but by burning
>     coolant!
>     That's what I learned from it.
>     Gary
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