High Efficiency 2-Stage 4-Stroke Reciprocating Engine
Modern Gasoline engines achieve 60% to 80% thermal efficiency. Some of the wasted energy is dissipated by the radiator. Most of the wasted energy goes out the exhaust.
This engine design recovers much of the wasted exhaust energy by directing it to a larger secondary cylinder (perhaps three times the displacement of the primary cylinder) which contains compressed air and water vapor. The heat from the primary cylinder exhaust expands the air / water vapor mixture to drive the secondary piston.
The secondary cylinder also contains a catalyst to promote oxidation of unburned hydrocarbons coming from the primary cylinder thus providing more gas expansion / pressure.
Catalytic converters for single stage engines are located in the exhaust system and require an extra air pump to provide air (oxygen) to complete combustion. This engine internally converts this waste to usable energy.
The secondary exhaust contains a thermal sensor which the computer uses to control the amount of water injection into the secondary air intake. This maintains the secondary exhaust temperature to achieve the optimum power output of the total engine.
<----- Primary | Secondary ----->
The engine above is shown as 2 opposed cylinders using one crank throw. Cylinder configuration may be improved by locating the primary & secondary cylinders side by side. This would enable a shorter, more efficient path between stages. Four, eight, twelve, and sixteen cylinder configurations in inline, opposed, or "V" configurations are also possible.