This idea is a mix between a split cycle engine and a steam engine.
Each cylinder would only require two valves (actually the first cylinder technically only needs one).
The first cylinder would suck the air in, and then compress it trough a crossover passage into the second cylinder, where fuel is then injected and ignited, after the expansion stroke the exhaust is then expelled as normal. The power cylinder would be insulated, but would have serpentine water passages which would be used to create steam for powering the third cylinder, the water would also prevent the power cylinder from overheating. In the third cylinder, one valve would open, and the pressure from the steam would press the piston down, the valve would then close and another valve would open to exhaust the steam, while the used steam is being expelled, the broiler would be building up pressure for the next steam power stroke.
Most of the water would be stored in a separate tank, and exhausted steam could possibly be condensed and reused in the engine.
The advantages of this engine are: It would be more efficient and water costs less than fuel, and each cylinder has its own function which means that they can be made better and cheaper for their function, and the boiler has thin serpentine passages which means that you wouldn't have to wait very long for the engine to start creating power from steam, and it has a higher power to weight ratio than four-stroke engines.
The engine could also be made as a 6 cylinder, or 9, or 12, or...-- BJS, Jul 25 2007 Split Cycle Engine http://en.wikipedia..._Split_Cycle_EngineThe links are good. [BJS, Jul 25 2007] HEHC engine http://www.liquidpi...TechnologyIntro.aspSame idea using 2 rotary cylinders [marklar, Jul 25 2007] Crower six-stroke http://en.wikipedia...i/Crower_six_strokeCrower adds a 2-stroke steam cycle after the 4-stroke gas/diesel cycle [phlogiston, Jul 26 2007] Alternatively, you could mix it up so that two cylinders are pumping the air into the power cylinder, but each one also uses steam and takes a 2-cycle "break" to have a steam expansion and exhaust cycle (so that one cylinder has a steam stroke while the other pumps in the air).
Great idea though, I'll take mine in a H-6 please [+].-- acurafan07, Jul 25 2007 That would work, but part of the reason I decided to do it this way was so that each cylinder has its own function.
What do you mean by "H-6"?
I think this engine would have approximately the same power output as a four stroke four cylinder engine.-- BJS, Jul 25 2007 Aren't you trying to defy the law of diminishing returns here?-- globaltourniquet, Jul 25 2007 Horizontally opposed (180 degree angle). No reason other than that I love the sound of them (think Porsche).-- acurafan07, Jul 25 2007 Neat idea. I especially like how it eliminates the cross contamination of a steam cycle in the same cylinder as the fuel cycle. (+)-- elhigh, Jul 25 2007 Baked I'm afraid, by the HEHC [linked].-- marklar, Jul 25 2007 Also partially baked by Crower. See linky. He adds a fifth stroke (water injection/power) and sixth (steam exhaust) to a normal 4-stroke engine. Reduces cooling requirements too, as the steam carries engine heat away neatly.-- phlogiston, Jul 26 2007 Be careful using the "H" designation [BJS], Subaru has been using it for their flat engines but it's more correctly used to describe a configuration of two flat engines running in parallel, with gears connecting the two crankshafts.
Incidentally, there are two types of flat engines--boxer is one of them, and the other is sometimes called 180 degree V, or flat V, because it uses the same sort of crankshaft found in a typical V engine.-- 5th Earth, Jul 26 2007 [5th Earth], you sure you don't mean to address me with that? I'm the one who mentioned an H-configuartion.
[BJS], did this part of my idea (posted about ten minutes before this one) get you to thinking about a 3 Cylinder Hybrid Engine at all "you cannot have a 3-cylinder Scuderi Split-Cycle engine"? If so, that's neat that you think that way. If not, that's a pretty weird coincidence.-- acurafan07, Jul 30 2007 Well, I don't think that is the reason I started to come up with the idea, but while I was thinking it up, I thought 3 cylinders would be best.
So I guess it's sort of both situations.-- BJS, Jul 31 2007 //Horizontally opposed (180 degree angle). No reason other than that I love the sound of them (think Porsche).// or Subaru... great sound-- evilpenguin, Jul 31 2007 random, halfbakery