Isn’t this much like how Diesel engines work? They compress air first to heat it to the point that when mixed with fuel it spontaneously ignites. Maybe glow plugs can make a comeback.
Also, glow plugs are only used for starting.
He also intended the fuel for it to be peanut oil or canola oil a crop farmers could grow for their tractors.
Glow plugs are still here sort of although now a heating grid. My diesel truck has it to pre-heat the air to make starting easier.