6 stroke engine idea?

[metromizer]

Originally Posted by Christ

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...

Link?

[Sunwapta]

I think steam from waste heat has huge potential. Plus steam I can generate incredible torque. However, I think it has to be thought of as a supplementary or delayed source of power. Just as solar won't likely power most houses, it still shouldn't be ruled out of service some supplemental or dedicated (say powering outside lights) role. Maybe steam off an exhaust system could drive some electric generator or a turbo/supercharger...

Why not have tri-brids? Say Diesel-Electric-Steam train engines. Maybe semi's could use steam from their big diesel engines (once they're hot and on the highway)...

[Big Dave]

Ever studied thermo? You are talking enormous weight and cost for minimal improvements in efficiency.

Compounding has been tried and even worked in limited applications - mostly aviation - but for motor vehicles, that characteristically operate far below peak power, the idea has been found wanting.

[Christ]

Originally Posted by metromizer

Link?

Can you remove videos from youtube? I haven't been able to find it, and the bookmark I have isn't getting me anywhere... I'll keep searching for it though, b/c something about it may have been more in-depth than I mention... or it may just be a complete fraud.

[Snorg]

If you use steam in there you also have to use an oil separator to get the water out of the crankcase.
You would also be washing the oil off the cylinder walls.

[Vwbeamer]

All production engines with cylinder deactivation keep both intake and exhaust valves closed.

If you leave one open, it will pump air and become a drag on the system.

With both valves closed, the trapped air acts as a spring and returns the energy it takes to compress the gas when the piston is on the down stroke..

If you open both valves and keep them open, it will pump fresh air into the exhaust and throw your O2 reading off.

Interesting thread on the subject-
Transmission, Driveline, Hybrid Drive engineering - Shade tree cylinder deactivation?


BTW, before reading the above thread, I would have agreed with you.

I posted a link on EGR in another thread here. EGR is the simplest way for a DIY variable displacement engine IMHO.

Spent exhaust gas is a source of inert gas- pump 1 litre of an inert gas into a 2 litre engine and you now have a 1 litre engine. Plus the combustion will be cooler, so you can run leaner, and more timing, without NOx forming.

Originally Posted by Christ

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?

[aerohead]

My opinion is that you would want to limit,not increase the amount of strokes in an engine.The power-stroke is the only useful stroke,all the others are cannibalizing power from it, stored in the flywheel,or robbed from other firing cylinders,in the case of a multi-cylinder engines.Unless additional strokes add at least as much energy as the original power stroke,you're operating at higher internal friction loads for less net efficiency of the engine, since internal friction is already at a minimum.

[Deezler]

Aerohead, this would be adding another power stroke. The steam exhaust stroke would consume far less energy than the expansion stroke, and the frictional losses should be less than what's added as well. You might need to run a higher rpm to get the same power output though, to offset the reduction in frequency of gasoline power strokes. But then your frictional losses have gone up also... wait a minute, this idea keeps getting worse.

I can't see this approach ever coming into mass production. The steam washes all the oil off the bores as someone already mentioned, and adds water dilution to the crankcase oil. You would end up with increased oil consumption and change intervals. I can't imagine the piston rings would like running on un-oiled cylinder bores either.

[Vwbeamer]

Steam engines ran for long periods in steam locomotives.

Not sure how many miles they would run between overhaul, but i would think they would be pretty durable.

[Christ]

There is a big difference between a "steam" engine and the idea of introducing steam to a gasoline ICE.