Does anyone have experience with pre-heating fuel and direct injection
into the engine?I'm thinking a re-capture of heat from the engine
coolant via heat exchanger, (controlled and managed, of course, to the
optimum temperature/vapour pressure), to recoup some of the energy
lost.Fuel combustion would be almost instantaneous and no carburetor
or standard fuel injection would appear to work.Only direct injection,
which the rotary engine is very capable of.

This has come up before with my ideas on wing surface radiators.How
will the heated fuel in the wing tanks react when heated up to the
coolant temps (200-250 deg)?Fuel tanks would have to be well vented.
At what temperature would the fuel completely vaporize?(A bad thing).
Am I trying to get something for nothing, or does this idea have any
merit?

Thanks

Greg Fleming
London, Ontario, Canada


It is not worth the trouble/hazard.  If it were (in this case), the
automobile mfg would be doing it.

1) Hazard: The hotter the liquid, the faster it vaporizes (regardless of
external pressure/temp).  In the event of a forced landing, etc, I want
the fuel on board to be as cool as possible.

2) Efficiency:  Warmer fuel= fewer mols/liter=  less range for a given
size tank.

3) Payoff too small:  The latent heat of vaporization for gasoline is
150 BTU/lb.  The heating value of the fuel is 18,676 BTU/lb.   So, for
all this trouble and danger, the payoff might be  00.8% improved fuel
efficiency.  It would be more efficient to build a tiny steam engine to
run off the engine exhaust heat that turns a generator that powers the
navigation lights.

Mark Waldron