Just curious, how would the liquid fuels compare to solid explosives? Can we build an engine that would snatch a tiny piece of a solid explosive, put that in the combustion chamber, and fire away?
Can you imagine the libs’ reaction to that proposal?
Honey, I need to run to the 7-11 to refill my tank with dynamite, do you need me to get the milk?
Explosives aren't all that high energy. For example TNT is only 4.6 megajoules/kg compared to gasoline's 46.4 MJ/kg. The thing with an explosive is that it will release all its energy at once.
I've heard that a block of C4 has the same energy as a block of butter, but I can't a reference to that, and the numbers I just looked up say that butter has a much higher energy density.
The energy density of gasoline exceeds that of black powder by several orders of magnitude, which is why fuel-air explosives are so devastating. Not sure about HE, though.