I came across this article a couple of days ago while I was researching vapor carburetors. The basic idea is that in order for fuel to vaporize completely in the combustion chamber it needs to be pre-heated. These guys built a heat exchanger and ran their fuel through it before it got to the intake manifold. Then, in order to minimize condensation of the fuel, they used another heat exchanger to heat the air mixing with the vaporized fuel. The article explains the process and several different experiments they conducted. In the end, they used a three valve butterfly system, two cold air and one hot air, intake system. Read the article and share your thoughts. The logic is sound as far as I can tell.
Fuel Vaporization Through Pre-Heating: Anthony P. O'Donnell Experiements