so i was reading on a web site about using hydrogen to boost gassers and diesels, and one thing they recommended was to preheat diesel fuel before it's burned. They had small heat exchangers that you're suppose to plumb into your fuel line, then use a coolant line to heat the fuel. Suppose to give a better burn.

is that true?...

 

heated fuel, to some extent, allows for better atomization at the tips. I cannot recall 100%, but I do believe that the number we were given was 165 degrees F, give or take a few degrees. I don't think it actually gives that much of an advantage, especially in newer engines, or even older detroits with the fuel rail in the head. The only reason for preheaters there, would be to prevent gelling at the filter.

Something to think about though.

 

every semi truck in the fleet i drive for has a fuel filter/water separater/fuel heater on it. the fuel is heated via engine coolant. mechanics say it makes for better fuel economy.

 

Research I read from Kubota said that the greatest power and efficiency on their engines was with a fuel temp of 750°F (400C) at the injector.
This was experimental only and not really practicable outside the lab.

 

Interesting Kubota research, and I believe it. Heating the fuel is a known fuel economy and efficiency trick and should work really well on an extremely high pressure fuel injected diesel. I will say that this idea is not popular with the patent office or the govt.
The weak link is the injectors. Heat and pressure are hard on them.