It sure would be nice to make use of all that drag-free surface area of the wings.

 

Evans coolant may just the stuff to design a cooling system around.  Simply route the heated coolant out to the wing tips where it could passively drain back through shallow bays on the lower surface of the wing and into a sump where an EWP could pump it back to the engine pump.  The bays in the wings would be very shallow to minimize weight, they would be sealed but need not be pressurized.  Evans is the perfect stuff because it need not be pressurized, is very non-corrosive and non-toxic.

 

Then there would be no need for a radiator at all.   Probably enough capacity there for a coolant/oil heat exchanger and whala, zero cooling drag...

 

Tracy, is it too late to make your RV-8 with zero cooling drag?  :-)

 

Dave Leonard

Dave, Peter Garrison did a column on this very subject. EXACTLY the same with exception of the evans coolant. Peters airplane has a fairly long span which would seem perfect for this scheme. When he ran the numbers he found there was nowhere near enough surface area on the wings to make this work. Too bad it does seem like a natural. The actual surface area of the heat exchangers in great. Look it up in the Flying archives. Peter Garrisons column is usually Technicalities.

Bill Jepson