A lot of people are pointing out that most engines are barely 50% fuel efficient. They don't make even 50% use of the potential energy in gasoline or diesel. What makes it so? Or to put it another way, How could you max out the fuel usage to get the most out of every drop? A) Combustion Chamber design? B) Squarer relationship with Rod Length and Piston Diameter? 3" Rod, 3" piston? C) Overhead Cam vs. ??? D) Solid Lifters vs Hydraulics - the more adjustments available, the more possibilities? E) Fuel and Spark delivery? Electric fuel pump, Water Pump, Oil Pump? Distriburoless ignition? F) Carb vs Fuel Injection or Fuel Vapouriser or Supercharger/Turbo? G) Should Compression go up or down, or is that strictly by specific engine? Probably other areas too. But the question is about getting better than 50% usage of the fuel energy that you pump into the engine. Fuel being anything that the thing can run on, but lets stay with pump petro (with or without ethanol or bio-diesel), just so we can have a common starting point. Comments? Let 'er rip guys. The oil man doesn't deserve a monthly mortgage payment to take you to work and back. Honest.
It's not that the fuel doesn't burn completely or close to completely. It does. It's the heat waste that makes internal combustion engines in general less efficient. That's why turbo charged engines are actually more efficient because some of the waste heat is used to compress the intake charge. No engine that burns anything will be even close to 100% efficient so long as there is exhaust heat that is not used to create work.
The few V8-powered boats I've seen, use lake water to cool the block, unlike our vehicles, so the heat waste you're speaking about is at the combustion chamber? Or should we run more fans to cool the block down. I've had Air-cooled VWs, Corvairs, and a Porsche, and they'd heat up.
