I can name at least 10 different sources of losses.

regards
gary

I just wanted to make sure people were aware that there's a lot going on to make big engine's bad. I didn't mean to nitpick.

A good read is to look at what Honda did to make the VX the non hybrid mileage champ of the Honda line from 92-95.

I actually have design for a valveless variable compression rotary piston engine. It has an additional capability of destroking itself completely and storing energy in its own spinning mass as a flywheel.

Combined with an Infinitely Variable, in wheel transmission at each wheel. it provides a potentially game changing powertrain configuration.

regards
gary

I am doing engine design work as well, but can't talk about it. IP issues suck. Be careful.