thoughts on Crower 6-stroke?

[maxc]

Originally Posted by jonr

Why not just do direct injection of water instead? Would be great for high output race engines where heat/detonation is a problem.

For normal use, I'll take variable intake valves (Atkinson cycle).

Curbside Classic: Incredible Steam-Injected, 12 Second 1/4 Mile, 75 MPG 1978 Mercury Bobcat | The Truth About Cars

[Allch Chcar]

Wow. If he increased the cylinder pressure 4 fold he'd crack the block before anything interesting happens.

This topic died out awhile ago. I've given up on Atkins Cycle and adding Steam cycle to an engine.

Water is not really good for direct injection, it's just cheaper. Ethanol is actually better because you get some usable energy and the latent heat of evaporation is higher(?). Methanol is even better than Ethanol in that aspect but most people who do Meth injection buy it mixed with water.

[Bicycle Bob]

All my thoughts about using steam power changed when I read the standard books on boiler design. The run from 10 to 12 square feet of boiler surface area per HP. That's with full time exposure and even, ideal temperatures.

[janvos39]

I think that if we want to make use of the engergy in the exhaust we best use a practical approach like Ilmor is taking by adding an expansion piston to the fourstroke cycle.
Ilmor Engineering builds a five-stroke engine — Autoblog
In this way no additional systems have to be added. Acceptance could be easy.You would not notice the difference in driving, only at the gasstation.

[Bicycle Bob]

That's a good way to increase efficiency at high output. What we want is to have the pressure in the (last) cylinder be close to atmospheric when the exhaust valve opens. That can also be obtained by limiting the intake. A bit of power can be recovered by using an intake turbine instead of a throttle plate, or the intake valve can just close early.

[janvos39]

Bob. You are right there are more ways to get there. I am working on a mechanism to vary the intake valve timing during driving. I hope to measure the result on the early closing of the intake valve. On my Burgman scooter.
And of course also late (too late) closing of the intake valve can be done . This than is the Atkinson way of reducing the intake amount and have a relative large exhaust expansion.

[pete c]

Rather than continue the new thread, I may as well add to this excellent thread.

Mods, could you kill my new one?

Reading this has me thinking maybe using the ICE, basically as a boiler for a small auxilliary steam engine, probably a turbine, would be the way to go.

I think using the engine block itself as the preheater and then the exhaust, just downstream of the cat to superheat it for usable steam pressure is the way to go.

My question is can such a system work as a closed loop so you wouldn't have to continually add water?

[oil pan 4]

Come up with a good boiler and superheater design and a lot is possible.

An open steam system is only going to be about 10% efficient, but who cares. If you can make a gas or diesel engine 5% more efficient you might be on to something.

Your test engine would have to be something like the odd ford 2 spark plug 2.3L or a diesel with glow plug ports that could be used for something else.

[user removed]

BMW unveils the turbosteamer concept

regards
Mech

[pete c]

Thanks for the link, OM. That is old enough that if they have decided it's economically feasible, it'd be here by now.

I suspect it is a matter of lowering the cost/raising the fuel cost, until it makes economic sense.