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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...
Split Cycle Engine
http://en.wikipedia..._Split_Cycle_Engine
The links are good. [BJS, Jul 25 2007]
HEHC engine
http://www.liquidpi...TechnologyIntro.asp
Same idea using 2 rotary cylinders [marklar, Jul 25 2007]
Crower six-stroke
http://en.wikipedia...i/Crower_six_stroke
Crower adds a 2-stroke steam cycle after the 4-stroke gas/diesel cycle [phlogiston, Jul 26 2007]
A brief tale of H2 abuse
https://wildguzzi.c...p?topic=68761.0;wap
[normzone, May 03 2026]
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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). |
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Great idea though, I'll take mine in a H-6 please [+]. |
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That would work, but part of the reason I decided to do it this way was so that each cylinder has its own function. |
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What do you mean by "H-6"? |
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I think this engine would have approximately the same power output as a four stroke four cylinder engine. |
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Aren't you trying to defy the law of diminishing returns here? |
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Horizontally opposed (180 degree angle). No reason other than that I love the sound of them (think Porsche). |
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Neat idea. I especially like how it eliminates the cross contamination of a steam cycle in the same cylinder as the fuel cycle. (+) |
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Baked I'm afraid, by the HEHC [linked]. |
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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. |
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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. |
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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. |
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[5th Earth], you sure you don't mean to address me with that? I'm the one who mentioned an H-configuartion. |
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[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. |
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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. |
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So I guess it's sort of both situations. |
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//Horizontally opposed (180 degree angle). No reason other than that I love the sound of them (think Porsche).// or Subaru... great sound |
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"Be careful using the "H" designation" |
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I owned an H2 "Widowmaker" for about five thousand miles, uncounted wheelies and one splendiferous crash, all of which I take full responsibility for (see link). |
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[norm] your link requires membership. |
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Thank you [whatrock] ... I'd never have noticed. |
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I'll kill some 'bakery pixels and post the tale here - |
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I found an old link to a tale I told of a motorcycle crash I caused some time ago ... I'll paste it here. |
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In this tale, it's 1980, I'm 24 years young and stupid, and I'm riding my H2. (This is a 1972 three cylinder, two stroke, 750cc Kawasaki colloquially referred to as "The Widowmaker" for it's insane acceleration and ridiculously flexible frame resulting in sloppy handling at best) |
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It's about six in the morning, I'm on my way to open the Shell service station in the north end of Sausalito. Beautiful redwood building between a liquor store and a coffee shop that makes whole wheat / honey donuts. Not a bad gig... |
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It's Bay Area COLD, and I'm drafting an old pickup truck with a camper shell on it. I am a night owl, not a dawn patrol type, and I'm not really awake yet. |
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I pass an exit that I've always wondered where it goes - it's about two exits before my usual, and it would be a short slow ride to work from there. |
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Being focused on huddling in the wake of the truck, I failed to note the [EXIT 20 MPH] sign I'd just passed - It had always been there and still was. Not anymore, they've remodeled the whole exit since then. |
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So on an impulse I twitched off the freeway and onto the exit at the very last second, going about 65. Dumb. |
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I realized immediately that I was screwed. The exit ramp ran steeply downhill at about 30 degrees away from the freeway for maybe fifty yards, then looped sharply to the left to go back under the freeway - probably about a 120 degree left turn. |
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Visualize the exit ramp as the numeral 7 descending sharply down and away from, then turning to go under the freeway. |
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My short life flashed before my eyes and I laid into the brakes. I thought briefly of the new rear tire sitting at home that was to replace the balding one on the back. The bike tires squealed and screamed, the rear end caught up with the front end and began to pass it. |
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I have never been that close to the ground without going down. I was skidding both tires side by side, leaving skid marks that looked like a car had braked there. I chickened out, stood the bike back up, and went off the road to the left, only about halfway down the hill to the sharp left turn at the top of the 7.
At least I'd shed a little speed, I was probably doing about 50 now cutting across the 7. |
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The next order of business was the two large highway signs supported on 4" x 4" posts - I think they said something about speed and caution or something of that nature. I aimed for the gap between them and as I went through it I noted that I had about six inches to spare on either side of the handle bars. |
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Feeling rather proud of myself for my handling skills, I set next to shed some more speed. I began laying onto the brakes again, and was disappointed to feel the absence of any response. I looked down to see why and was dismayed to see about five foot of air between my tires and the ground. |
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So I air braked and came down on the dirt slope short of the cutback road below. When the front tire bit dirt I braked again but I bounced and lost the bike. |
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I kept on going, head over heels through the air. I like to think I'd shed some more speed in my brief attempts but I'd left the speedometer with the bike back on the hill and truthfully had not spent much time looking at it for the last few seconds. |
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About fifty feet away there was a bunch of tall pine trees. I flew head over heels through the air across the base of the hill, across the road comprising the top of the 7, across the road shoulder and went head first into the pine branches. This was pre-helmet law, but I had my trusty bandanna on. |
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Everything was green for a bit, then I completed my final flip, stretched out straight like I was lying in bed on my back. I thwacked feet first into the tree trunk with the soles of my boots. |
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It was a pure Wiley Coyote moment. I hung there in the air, surviving and triumphant, horizontal and largely uninjured.
Then I realized I was still about fifteen feet above the ground, and the ground around the tree was covered with pointy bowling ball sized rocks. After a momentary pause, I fell out of the tree and onto the rocks. I landed on my back, and this time the celebration did not include the "uninjured" part. Oh, and I'd lost my glasses. |
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As I began cursing my luck, my glasses fell out of the tree and landed on my chest - unbroken. I lay there and listened to the bike run out of gas, one cylinder after the other after the other. |
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After some prayer and cursing, I went back to the road and picked my bike up. It had bounced down the hill onto the street. Handle bar bent, tank dented, dirt inside the broken headlight, tools spilling out of my torn saddlebag. |
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A motorcycle came up the hill - "did you just go down?" said the rider? "I was on the freeway above and I saw a bike lying on the road with nobody around". I assured him that I was in shock but could ride, and went to open the service station. I remember customers asking how I managed to fill my headlight with dirt.
It took days to get the pine sap out of my hair. |
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Funny thing, though. I fixed the H2, bartered it away for a little cash, a bicycle and some power tools. I rode the bicycle for a couple of months, and one day while breezing with a customer about how I would like to get an old Norton basket case or such, another customer overheard me. |
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He came over and asked if I was interested in a not running Moto Guzzi. "I have no clue what kind of bike that is" I said. You know what that led to... |
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