"Philippe Vessaire" wrote

The fuel/water heat exchanger is standard on diesel cars. For an hombuilt,
juste take one and bolt in somewhere bear the engine.
The return fuel is able to do the job and the whole tank will be warmer
enought for safe operation.

For biodiesel cars, some people juste run a copper tube near exhaut and
the
same job is done. These cars still need a pure diesel start and stop.

Right. It is a good idea to warm the fuel, but you can not use the fuel to
get rid of all of the engine's waste heat.
--
Jim in NC