Bob Engelhardt wrote:

What occurs to me is that this could be the solution to the running-lean
problem. Gas engines run way richer than they need to, 'cause running
lean gets too hot. But lean is more fuel efficient so if you can keep
the heat down with the water cycle you could run lean & gain that
efficiency, in addition to recovering the "radiator" heat.

Another good point.

R,
Tom Q.