March 20, 2006

Six Cycle Engine

Very cool actually -- the inventor, Bruce Crower, has been involved in racing and currently builds high-performance cams and other engine parts. From Damn Interesting:
The Six-Stroke Engine
Under the hood of almost all modern automobiles there sits a four-stroke internal combustion engine (ICE). Though the efficiency of the design has been improved upon significantly in the intervening years, the basic concept is the same today as that used by the first practical four-stroke engine built in the 1870s. During every cycle in a typical car engine, each piston moves up and down twice in the chamber, resulting in four total strokes… one of which is the power stroke that provides the torque to move the vehicle. But the automotive industry may soon be revolutionized by a new six-stroke design which adds a second power stroke, resulting in a much more efficient and less polluting alternative.
A bit more:
His addition to the ICE design is simple in principle, yet a stroke of genius. After the exhaust cycles out of the chamber, rather than squirting more fuel and air into the chamber, his design injects ordinary water. Inside the extremely hot chamber, the water immediately turns to steam -- expanding to 1600 times its volume -- which forces the piston down for a second power stroke. Another exhaust cycle pushes the steam out of the chamber, and then the six-stroke cycle begins again.

Besides providing power, this water injection cycle cools the engine from within, making an engine's heavy radiator, coolant, and fans obsolete. Despite its lack of a conventional liquid cooling system, his bench engine is only warm to the touch while it is running.
Clever idea -- the engine gets a bit more power from the waste heat (the article is stating 40% more power). There is a downside in that the vehicle will need to carry as much water as gasoline so the weight saved by not needing a radiator and cooling system is somewhat lost by the extra baggage but still, this is not a bad idea and would be fantastic for a fixed engine such as a generator... Posted by DaveH at March 20, 2006 9:25 AM