[olddog]

A fellow by the name of Crower is working on a 6 stroke diesel.
1) intalke
2) compression
3) power (diesel injection)
near the end of this power stroke the exhaust valve vents off the pressure.
4) re-compression (of remaining exhaust gas)
5) power (by direct injection of water)
6) exhaust stroke

Now what is very key to this design is that the cooling system is done away with. The injection of water and making of steam directly cools the combustion chamber. Research engines are making about 20% more power on the same quantity of fuel.