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Things have been a little dull on the list, since Dave
reported on his "adventure".
Also, I recently received a phone call from a rotary
enthusiast (not on the list) about the use of Evans NPG (Propylene Glycol) in
rotary engines. I did a bit of research and my conclusion was the rotary
engine was not well suited to benefit from the properties of NPG in its
stock coolant system configuration.
That the use of 100% glycol would require
increased coolant flow rates by 10-15% and more coolant pump power would be
required (hard to quantify this one but it appears in the range of 15-25%
more). Also the hazard of fire due to a leak on hot exhaust would be
increased (this would apply to a 100% mixture of either Ethylene or Propylene
glycol). There are benefits to using NPG, however, in my opinion the
effort needed to change the rotary cooling configuration to safely
use it makes the cost effectiveness of the conversion questionable.
The apparent success of Evans NPG in reciprocating engines
is not in conflict with my assessment about its suitability for the rotary
engine.
Attached is some supporting (I believe) facts to support
this opinion (and that is all it is).
Ed
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