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If you were flowing the same volume as the OEM installations, then no, you
would not need to flow more fluid. (You'd just see temperature increase). Looks
like most of you flow substantially less coolant than OEM, so Evans would be a
disaster. We had well proven example in a Subaru. This guy used 3/4" radiator
tubing as I recall. Temperatures went to hell a number of months after first
flight. Boil over. He switched to evans and it got substantially worse. Boil
over. This is uncharacteristic. Ended up his unusually long coolant lines,
combined with small diameter tubing, represented something like 80% reduction in
coolant flow (compared to OEM). Since evans made it so much worse, it was
obvious he had restricted coolant flow excessively. He changed to 1" coolant
lines, all symptoms permanently disappeared. I believe he went back to
traditional coolant. His radiators are in the wing.
Doesn't matter though, as Evans is only advantage if your engine likes
higher temps. Since it is less efficient. Not desirable for the rotary.
So, all in all, I agree with your statement Ed.
I have mentioned several times in discussions regarding
the EVANS coolant
that to really gain benefits from its use that the
coolant flow would have to be increased to ensure the removal of adequate heat
from the engine. The fact that the EVANS has a 300F+ boiling point may
delay "boil over" but it does little to protect our rotary's because they are
cooked long before that point is reached. In fact, the 250F boil over of
the 50/50 mixture pretty much ensures that if you reach those temps you have
probably cooked your engine. However, preventing Boil-over (as Al Wick
has mentioned) is a worthwhile consideration.
But, all that aside, my point was that give the lower
specific heat and the fact that the rotary engine is more constrained
temperature wise- means that to flow the same amount of heat out of
your engine per unit time with Evans - you MUST increase the coolant flow
rate. IF you do increase the flow rate with Evans to the point that the
coolant temperatures are within the limits for the rotary then you stand a
much better chance of benefiting from using EVANS.
I happen to notice in reading material on the EVANS
coolant, that the above point is also made by them: This is a direct
quote from material on their web site.
"THE EVANS SYSTEM
Since the Evans coolant possesses different
flow and thermal characteristics than normal EGW, some changes are in
order. First, there is no need to use a pressurized cooling
system, but an overflow bottle is necessary due to the expansion rate of the
coolant. Evans markets 0- and 4-lb. caps for most radiators. The low-pressure
cap is used to keep coolant loss in check on late-model engines. To
totally optimize this system,
a high-flow Evans water pump, thermostat and
radiator should be installed. Working with data from the
field, most late-model performance
cars, unless approaching the 650-hp level, can reap substantial performance
gains with just the installation of the Evans coolant and high-flow thermostat.
Realizing the huge potential for power generation through the use of this
coolant, Evans has designed many ancillary components to maximize the
potential for late-model fuel-injected
engines. Pulleys to increase stock
water pump speeds, water pump application for TPl, 5.0s and
Buick GNs along with radiators. "
Note the reference to late-model performance cars is a
reference to the fact that these newer engines are designed for and
operate at higher coolant temperatures (more fuel efficiency) than
previous engines (or our rotary engines).
The point is as EVANS points out - there are some
definite benefits to EVANs. However to gain the maximum benefit and
given our rotary's lower temperature limits, I personally believe these
changes are essential if you want a system that keeps you engine within
safe limits.
The changes Evan's mentions include high flow
pumps, pulleys for faster flow, high flow thermostat and high flow
radiators. This implies (to me at least) that if you are going to use
Evans then you need to design your coolant system for its use from the
git-go.
My trouble-making 0.02 {:>)
Ed
-al wick
Cozy IV powered by Turbo Subaru
3.0R with variable valve lift and cam timing.
Artificial intelligence in
cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel design, Subaru
install, Prop construct, Risk assessment
info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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