Internal injection flash steam heat engine.

Take a motorcycle engine, block off the intake, replace the spark plugs with fuel injectors hooked up to a water source, put the whole thing on a stand several feet in the air and build an entire array of mirrors around it to focus the sun on the top of the cylinder heads where the air cooling fins are in place. Now... wait for the top end to get to a few hundred degrees and inject water at top dead center.

Advantages:

• Safety. No high pressure boiler.
• Uses any heat source
• Minimal, no or low precision construction.

Disadvantages

• Low effeciency
• Takes up lots of room for the mirror array
• Bearings wear out or engine cease due to high temp
• Injectors rust.

This should be easy to try.

• Open the head and snap off the intake valve stem with a hammer or grind it or the intake cam down
• Adjust the timeing so the exaust valve closes much later and
• Grind off part of the exaust cam so that it still opens at the bottom.
• Bodge some way of inserting the fuel injector into the spark plug hole and
• Wire it to fire at TDC.

Comments:

• This has been an interesting discussion. The one fact that I notice missing in these calculated thoughts is that of "Latent Heat of Steam" It is not just high temperature. It is like heating a kettle of soup with a candle or campfire. Calories or BTU are important heat units that need to be calculated into these ideas. Look up Steam in an encyclopedia.+
• KILLspamj.w.holmes@spam@ at att.net

  Hi chevboy_67,
  I don't think the engine James is describing has a compression stroke at all. However a four cycle steam engine does use the compression stroke. As far as your question goes' using a big compression ratio such as a diesel engine does' I do not think this will be a sufficant source of heat(alone) to flash cold water to steam. It mainly has to do with the density of air or compressed air. Its just not nor will ever be, as dense as the material the engine block is made from, which is a good conductor of heat. Try this example, you can start a really big fire with a single match, but you can't make much steam from a single match. In other words the heat derived from compression in a diesel engine is adiquate to cause combustion. But "most likely" there won't be enough heat to flash steam of sufficant quantity, or repeatedly in a cyclic fashion. One of the big benifits of James engine design is the mass of the engine block itself acts as a thermal battery. This will allow the engine to run for a duration of time. But the heat that is derived from compression is very benifical to a four cycle steam engine cycle. But I just don't think its enough to run the engine solely from that, as the only source of heat. If the engine has a compression stroke at all, I think it's good, but it is unclear to me where deminshing returns occur, with a really big compression ratio such as 20 to 1, I have had really good results with this, at 8 to 1 or less. No matter what, if you heat the block and the compression stroke is still intact, then it will generate surplus heat that wouldnt normally be there. Hey, the board is active I'm impressed.

• KILLspamchevboy_67@spam@ at hotmail.com

  why couldn't you use a diesel engine design with an even higher compression ratio? by injecting the water at the max compression of the cylinder, the heat generated by the compression of the air should flash the water into steam.

• KILLspamj.w.holmes@spam@ at att.net Says:

  You will need a high-pressure capable injector to a reach high operating speed with your engine. also if variable valve lift is incorperated in such a valve. you will be able to very very acuritely control the speed. I have already done this. check out www.flashsteam.com

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  James Newton replies:

  I don't think so... My idea is to inject cool (non-heated) water into a heated cylinder. Since there is no need to compress the "fuel" at top dead center, the exhaust valving could be modified to stay open until just before TDC rather than closing at the bottom before a compression stroke. At TDC, there would be NO pressure in the cylinder. A fuel injector will probably be overkill. Any water spray mechanism would be sufficient.

  I must say, your efforts are very interesting and have a better chance of producing a device that would be fuel efficient.

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  KILLspamj.w.holmes@spam@ at att.net replies:

  I would like to state that you are theoretically you are correct. You could in fact wait for the top end to heat up to a couple hundred degrees. And set up a simple cold water injection system. Thru the spark plug port. And the engine probably would run. It is interesting that you are using a two cycle approache. And also that in your design that air cooling fins are common on motorcycle engine's. And that a "pod of aluminum fins" is an exellent solar energy receptor.

  I'd like to say that I'm impressed with your idea. And I like the simplicity aspect. I have some slightly different ideas. But you are heading in the proper direction. And engine cycles are usually a matter of personal choice. It seems that your proposed modifications would make the engine a continuous cycle. like a turbine. differing from the original intermittent engine cycle (four stroke). But the valve train modifications that you speak of are very difficult to make. and that you most likely will only get one power stroke per two crankshaft revolutions (or 720*). But you could fix that by changing the gear ratio from the crank to the cam. In addition to cam lobe modifications. Personally I don't recommend this modification since it is exceedingly difficult. Also Just because there's no compression doesn't mean you don't need at least 400psi on your water delivery device. Trust me I have experience with this. The main thing that you need to realize is that when any piston engine runs. the TDC power stroke occurs several times per second. And your cycle would be more frequent at once per 360*. A four cycle is- about 5hz at idle and 30hz at around 2000rpm.

  To get the water in the right place at the right time you need substantial pressure behind it. One thing that is relative in my experiments is the relation to engine speed to injector pressure. for example at 400psi you will be lucky to get 500rpm. And to get the engine to run faster you always need more pressure. when the water has more pressure behind it can move faster. maintaining volume of delivery even thou it has less time to enter the engine cylinder. as the engine reaches speed. The window of time that the water has to travel into the cylinder is very short. without some pressure it just wont get there in time. The fact an engine that has a compression stroke or not makes no difference in this situation. I think that the engine you describe will run.... with low pressure injection -but performance will be less than desirable (very slow/low power). But I would like to stress that what you are describing is a true flash steam engine.

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  James Newton replies:

  Thanks Jeremy. I agree totally re: cycles and the difficulty of modifying cam shafts... I have done it, but I basically made a new cam shaft and then case hardened it after it was done. (see below)

  I was thinking that IF the valve clearence were not an issue (valve hitting piston; note that the intake is no longer necessary so the valve would be removed or just have the stem broken off so that it would always be closed.) then the timeing could just be adjusted so that the exaust valve would open (and close) much later. It would close just before TDC. This would cause it to open quite late, but rather than depending on that for pressure release, a small hole could be drilled in the cylinder wall near the lowest point cleared by the top of the piston. The overall effect here is to reduce the pressure in the cylinder at TDC to the point that a standard fuel injector can be used.

  Another idea: It might even be possible to drill a second hole, lower than the "exaust" release hole, and have the water just pour into the cylinder into a "bucket" made of an insulated material on top of the piston. Then the cylinder head would have a set of "fingers" or fins (possibly steel wool for max surface area?) that would stick down into the water bucket at TDC... In this case, the exaust valve would also be blocked, and there would be compression at TDC, but the "fuel" would already be sealed in the cylinder. I think you could almost get away with makeing this modification with no more dissassembly than removeing the valve covers (to bust the stems) as long as you could find a way to smooth out the inside edge of the holes in the cylinder wall. Many small engines for hobby or demonstration use have been built with this sort of port "valving" (as you probably know) and I have seen at least one where the fuel was "injected" (gravity feed) at the bottom of the stroke and ignited at the top... via a glow plug as I remember. It was a little thing and I don't remember what it burned, but I expect that it was less volitile than gas or had a much higher combustion point.

  Actually the cam-shaft modifications are not impossible. When my father and I made a steam engine (not a flash steam engine) from a Brigs and Stratton gas motor, we removed the cam-shaft, heated and slowly cooled the side of the cam we wanted to add to, ground past the case hardening to make a flat spot, then silver soldered on a chunk of metal. ground it to the shape we needed and then ground off some material on the other side of the original cam lobe. It was a pain... Last time I did that, I just shifted the cam shaft down a bit so that the original cam lobes missed the valve stems and then welded on a new set of lobes of my own design... I was lucky there, to have the room, and to be able to shift the shaft enough without pulling the ends out of the bearings. And I was able to setup an actuator that moved the shaft back and forth between the original and new cams. It was a heck of a hack! <GRIN> I wasn't selling it so good enough was good enough.

  In the long view, I don't think that any of my ideas would result in an efficient engine... but since my goal is very (VERY) low cost solar power systems, and the fuel is free, who cares? For higher end, efficient fuel burning systems, I can see the advantage of high pressure injection... But I think the heating (and so the flash to steam) might be better done with a heat transfer system inside the cylinder... Why heat the water when you have to heat the head anyway? Then the "heat of rejection" is 100%. Perhaps heating the cylinder head or makeing a new head with a heat conduction system down the middle.. copper rods or something with the other end sitting in the corn burner. What do you think?

• KILLspamj.w.holmes@spam@ at att.net James you have some very dynamic reasoning skills. I think its cool that you built a steam engine with your dad. In fact I remember visiting steam fairs sponsored by my grandmother's brother. When I was young. they were in Michigan and were called the steam engine days. My grandpa says it was he's uncle Babe Ott. They would have an auction and a small flea market and such. And people would be there running steam engines that powered farm equiptment. I remember this one year they took us over to the work shop. And showed us one of the restorations, that uncle Babe's son was working on. It was a full size steam farm tractor that was buried in the woods somewhere in Canada.
  
  I agree with you in the fact that the valve train in an engine maybe modified to accomplish what your saying.
  
  In my opinion.. If.... you can make the engine work under its natural configuration. Such as four cycle. You are better off in general. But you will need a high pressure capable injection system to do this. Since the idea of running a four cycle steam engine is essentally obvious. "i.e." just substituting a chemical reaction with a thermodynamic one. A four cycle steam engine should not be patentable. So anyone should feel free to try to run a four cycle steam engine.
  
  It is interesting that you mentioned drilling a hole in the side of the cylinder. In fact in some configurations for direct injection. Drilling a hole in the side of the cylinder is the technique of getting the gasoline in. I first heard about this being done in 1993. It was done by a large auto manufacturer. And they had problems using a standard fuel injector. But they did something and it apparently worked. The vehicle got 80 miles to the gallon. Reportedly with good performance. Unfortunately this technique won't work for the flash steam engine. With an "I.C." engine you have the luxury of being able to initiate the reaction of the power pulse or combustion at anytime. Thru the spark plug. So the expandable liquid may enter at the bottom of the stroke and conveniently won't react until the spark plug fires. It doesn't happen this way with a flash steam engine. In fact the instant the water enters the combustion chamber (or cylinder) it starts to flash. This will cause pressure compression on an up stroke. Or go strait out the exhuast with your modifications.
  
  Heat of rejection is a strange "animal". And will not apply in the flash steam engine you describe. Since you only have one heat input source for your engine cycle. "i.e." the heated engine block. And heat of rejection attempts to explain temperature gradient (or difference) of the btu energy between "two" heat source inputs. The second heat source is there mainly to improve engine performance. And heat of rejection offers an explanation "why". The engine cycle that your working with is simpler to explain thermodynamically. Since you can use the steam tables "1 to 1". And the cold water that is being injected into the engine. Will cool the engine down in a simple to calculate way (neglecting the mass of the engine block)By contrast when you inject superheated water (pre-heated) the engine block conserves heat. And does not cool down in the same way or as fast. As with a single heat source as you are suggesting.
  
  Your concept of simplicity and low cost is admirable. And I hope to see your engine running.+

• mitxela says: "After a little research, I found someone's invented a "six stroke cycle", where the two further strokes are water being injected and evaporating to drive the piston down. It's around 60% efficient, which is good, but needs a supply of water, of course."

See also:

• /techref/member/plp-actcom-f00/sun-turbo-1.htm Brayton cycle solar hot air engine design.+
• Heat Engines
• James Newton refers to " http://www.fieldlines.com/story/2003/6/26/10248/0825 More or less the same idea. Some interesting variations. The use of an existing engine was not mentioned as far as I could see."
• http://www.redrok.com/engine.htm Heat Engine Projects
• http://darkwing.uoregon.edu/~linke/res_droplets.html Really interesting effect from the water droplet on a hot surface. This is related to the issues involved in getting water to flash boil when hitting a heated metal surface. If the surface is smooth or even mostly smooth, it forms a vapor barrier between the water and the surface and prevents the rest of the water from boiling. These people have found that the correct shape on the surface can actually cause the water to accellerate along the surface and hope to make a water pump based on the effect.

Questions:

• KILLspamsawbikes@spam@ at yahoo.ca asks: " I have 11.2 to one compression on a 68 350 gm. what shall I do to make it run on water?"
• KILLspambruceashowalter@spam@ at sbcglobal.net asks:

  What a concept!... I've heard of a "hot plate" type flash steam engine, but not of one that uses the heat of ambient air to flash the steam... I'm impressed. Correct me if I am wrong, but isn't the temperature inside the combustion chamber prior to injection on a diesel is around 500 degrees? It seems this would be plenty to expand a water vapor injected into it with no modification. Has anyone tried such a thing? How interesting

  James Newton replies: I've only done simple experiments with pots an pans. No time.+

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