OT: Interesting new idea, the six-stroke engine Options

[lapuwali]

Crower (of Crower Cams) has just patented a new "six stroke" engine design. The crank turns 3 times for each single cam revolution. The extra two piston strokes are after the normal exhaust stroke, and involve water direct injection into a closed cylinder. This flashes into steam, and produces a second power stroke. The exhaust then opens to vent the steam. Enough heat is drawn off by this steam production that no actual cooling system is required.

It's claimed this can improve fuel economy by as much as 40%.

He's got a single-cylinder spark-ignition prototype working, and is now working on a compression-ignition version.

[lapuwali]

QUOTE (Dead Air @ Mar 1 2006, 05:16 AM)

I'm NO engineer, but for atomized fuel to burn effeciently doesn't the combustion chamber need to be at a certain temperature? If the water cooled the chamber beyond that point, it seems the engine would be fighting with itself to maintain efficiency? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

Yes, quite right. The trick is to cool the engine enough that it won't self-destruct, but not so much that you end up with poor thermal efficiency, as the energy in the fuel will go to heating up the engine rather than pushing the piston. Essentially, the engine would spend all of its time "warming up".

It looks like this system could control cooling quite precisely, by varying the amount of water injected on each cycle. At some point, there's going to be an equilibrium between gaining power from the steam stroke, and losing it from overcooling. A dyno will quickly allow you to find this point (these points, more likely, as this will certainly vary as load changes), and you can program the water injection system accordingly.