6 stroke engine idea?

[fredd7924]

Im not sure if any of you have ever heard of the 6 stroke engine, but i was reading about it the other day and it seemed like a pretty good idea. Its a basic 4 stroke engine, but with 2 more strokes added. at the top of the 4th stroke, they inject water, the water turns to steam, expanding causing the piston to go down. the 6th stroke is just to remove the steam.

Here is a link http://www.autoweek.com/apps/pbcs.dl...THISWEEKSISSUE

http://en.wikipedia.org/wiki/Crower_six_stroke

it is supposed to use wasted heat energy. you would probably have to use stainless steel parts to prevent corrosion. Just an idea to ponder on.

[Andyman]

I've seen that before. I think he's being too optimistic about the fuel savings. I haven't seen any test results so far. BMW was experimenting with using a steam engine (the Turbosteamer) to use the waste heat of a gasoline engine and they said that the efficiency would be up to 15% better. It seems wasteful to allow the exhaust gas to escape and then use just the heated combustion chamber to generate steam. I wonder if it would be better to inject water into cylinder during the power stroke and keep the engine running as a four stroke.

http://en.wikipedia.org/wiki/Turbosteamer

[metroschultz]

Or maybe don't empty all the exhaust, just enough to let the piston come up easily, then do the water injection.
maybe, maybe not?
S.

[NoCO2]

Originally Posted by Andyman

It seems wasteful to allow the exhaust gas to escape and then use just the heated combustion chamber to generate steam.

I wonder if there is a way to collect your exhaust gases, and then pressurize them in a tank so that it can then be injected into the cylinder for one more cycle and a spark will be applied to burn off any extra fuel, but the main propellant will be the pressure of the gas going into the cylinder...much like an air car.

[Andyman]

Yes, it should help if the exhaust valve is closed long before the piston gets to the end of the exhaust stroke. In fact, if the engine is strong enough, it may be possible to cancel the first exhaust stroke and turn it into a high pressure compression stroke. It would be smart to use some kind of heat barrier coating in the combustion chamber to avoid too much heat loss.

http://www.hotrod.com/techarticles/e...ech/index.html

Another possibility would be to route the exhaust gases from the exhaust manifold into an expansion engine (like a steam engine) while adding some water.

To respond to NoCO2, yes, I think it makes sense to put the gases into a tank during the exhaust stroke. To get the maximum benefit from the pressurized gas, you would need at least two expansion strokes for every power stroke because the volume of exhaust gas at atmospheric pressure is more than twice that of the intake fuel mixture because of the higher temperature. Using two expansion strokes would turn it into an eight stroke engine if using one cylinder to do everything. Valve control would be complicated but definitely possible. It might be simpler to use separate cylinders to use just for expanding the exhaust gases with steam. They would operate on a two stroke cycle, just intake/expansion and exhaust.

I don't think a spark could ignite any more fuel left in the exhaust gas.

[AXMonster]

How about water injection through the intake to turn to steam and assist with expansion (hence power) during the power stroke?
It also effectively provides detonation supression so more ignition advance can be used.
IIRC approximately as much water can be injected as is fuel without causing combustion problems.

http://autospeed.com/cms/A_110368/article.html
http://autospeed.com/cms/A_110369/article.html

[Bicycle Bob]

I just looked up the ancient rule of thumb for boilers, and it suggests that Crower would need about ten square feet of "boiler area" per horsepower. That's a lot of little holes in the head. In general, there's twice as much heat going out the exhaust as out the radiator.

It might be worth while to use some cylinders as steam engines at cruise power, and only burn fuel in them for maximum output. It is probably better than just turning them off with the piston still moving, as is sometimes done.

[eco_generator]

Originally Posted by Bicycle Bob

It might be worth while to use some cylinders as steam engines at cruise power, and only burn fuel in them for maximum output. It is probably better than just turning them off with the piston still moving, as is sometimes done.

On some of the cylinder deactivation engines all the valves stay closed in that cylinder, too. So only a very small portion of energy is lost from pressurizing and depressurizing the air. Sort of like an air trampoline for that piston.

[mopo3]

First off you would have to use pure deionized water or else you would get buildup on the pistons from when the water boils off and the everything else stays behind (like boiling salt water).

second you would need a water tank to keep up with.

Third you would probably run the exhaust through your water tank after the catalytic converter to pre-heat the water before it is injected into the chamber, and if you kept the water at higher pressures then it wouldn't boil until the pressure lowers.

[Christ]

Originally Posted by eco_modder

On some of the cylinder deactivation engines all the valves stay closed in that cylinder, too. So only a very small portion of energy is lost from pressurizing and depressurizing the air. Sort of like an air trampoline for that piston.

Better to leave all the "dead" pistons with their valves open - constantly. Still take advantage of exhaust pulses, although not as much.

There was an experiment done *youtube, of all places* where someone ran the exhaust on his Geo 1.0 liter engine from 2 cylinders into the last cylinder in the firing order (I think it's 1 - 3 - 2, so 1&3 get run into 2) and just reburnt the exhaust gasses without introducing any more fuel or air into the mix.

I never thought into it very far, and I don't plan on it, but maybe someone could comment on the validity of something like that?