Slithr

Thoughts on Crower's new 6 stroke?

For those that haven't seen the (short) article, two strokes are added to the conventional 4 stroke cycle. At the end of the exhaust stroke, all valves are closed and water is injected into the cylinder, it flashes to steam and drives the piston down again.

Several benefits: 2 power strokes in 6 cycles, steam tends to cleanse the emissions, creation of the steam also pulls heat out of the engine eliminating the need for an external cooling system, 40% reduction in fuel usage.

He has a running single cylinder model. I thought it was pretty interesting and seriously out of the box.

protokultur

Very interesting, I read about that too - here is the link: http://www.autoweek.com/apps/pbcs.dll/arti...E/60222004/1024

vader1

very cool. That is a really neat idea. You would have to mix some alcohol in the water tank in winter months and I would still like SOME external cooling for safety.

You also have to make sure you had failsafe so that you could not over add water. A hot engine can turn water into steam and create tremendous force. I was in a beater in highschool that a friend drove through a deep puddle in a downpour. The engine gulped in some water and threw two pistons.


Sounds like a billion dollar idea.

Traveler

It's an interesting idea, but he's pulling that 40% out of his hat. It might reduce fuel usage, it might reduce emissions, it might ...

Until he measures the power output there's no way to know if he's made a more efficient engine, or a really inefficient steam generator.

Slamnasty

Well, if it failed it wouldn't be a good steam generator either, because you'd have to separate it from the exhaust.

But it's a cool idea though. I'm willing to back someone who's willing to try a new take on something.

NEODYMIUM

There is going to be a lot of heat loss from the air/fuel charge into the cylinder walls, it's gonna need some relatively high compression.

Mossad

I'm no IC expert, but the reason that your friend's car likely blew two pistons after gulping water isn't because it flashed to steam and caused a whole lot of power, but rather because water doesn't compress, and when it was introduced into the cylinders, the pistons attempted to compress the uncompressable and paid the ultimate price for it.

no_really

water + steel/iron + high heat = very fast corrosion. You have to use a variety of additives with boiler systems to control this, and in this engine's case, I'm not sure using distilled water is a very good approach. I'm not sure the idea is going to work with existing technology. If you could use ceramics or some other non-corroding substance for engine and exhaust components, it might work. But even if you could, water is a lot heavier than fuel, and that heat generated in combustion isn't totally wasted. How are you going to heat a vehicle if there is no excess heat from combustion? Vehicles using this engine going to have to carry as much water as fuel, and also some form of heating equipment. I'm not seeing a benefit as far as efficiency is concerned. And I predict bad, bad things happeneing to your engine when you run out of water but keep feeding it fuel. It sounds like it would make more sense as electric generating power source rather than as a propulsion system.

And I am kind of curious what kind of funky chemicals are created when steam meets hot exhaust gasses. I'm thinking all kinds of neat acids and other non-fun by-products will result. Of course, these things can be adressed somewhere down the line. It just sounds like a better stationary power source than a car engine.

Slithr

Interesting points. It looks like 2 power strokes in 6 cycles instead of 2 in 8, so I can see where there would be some gain. I don't know what hauling around a load of water would cost you in fuel mileage and performance. 20 gallons of water equals about 160 lbs, so it isn't too bad. You would have to have a system that would shut the engine down if you ran out of water. You could just use electric heat, especially if you combined this with current hybrid technology.

As far as the corrosion, who knows? There will also be oil there so that might slow and/or stop some of that. Could also use something other than a steel/iron cylinder.

I'm sure there are plenty of hurdles to overcome and it may never make it to market. It's good to see some people thinking creatively, especially an old hot rodder.

Wildncrazy

He says you don't need a cooling system so that's something as as far as what compounds are formed when steam meets the exhaust he says it is much cleaner. That seems to jive with something I read in another source a while back.

He also said that he felt he could us a much higher compression ratio due to the introduction of water without any worries about ping or knock.