High compression water fueled cobustion engine

[Hallman67]

Hi, im new to this forum & this is my first post. just some general info to keep in mind when replying - im 19 and about to start college in a few months so dont slam me when replying lol.

Anyways... about a month ago i had an interesting idea of converting a normal fuel injected engine to run on expanding water/steam via upping the compression ratio and injecting water instead of LPG.

the thought process behind this idea is that compressing a gas such as air increases temperature of said gas, and if compressing ratio was high enough you could just inject water to achieve the power stroke because of rappid expansion of the water

the only complications of such an engine would the integrity of the block structure at such high compression, and valve clearance.
other than that i dont see why this cant work..

was just interested in others opinion with more education than my own so thanks

[tachyon]

so you want to make a steam engine huh?

[Hallman67]

to an extent thats basically what it is, but not using premade steam

[Kokomoj0]

it takes power to compress air

why not just slap a valve shut and inject a drop of water on a red hot plate or similar in the cylinder head.

[Hallman67]

hmm... i think i see what your getting at, im sure i could further expand on that idea. but i could easily solve the starting of my proposed design by slapping a starter motor on steroids on it, after it starts it'll keep going via the co-operating 4 stroke cycle

[Kokomoj0]

I suppose if you used a red hot plate and injector all you would need is an exhaust port like a 2 cycle

[Hallman67]

only way i could imagine that working is if there was an ecu controlled hot plate "donut plate" embeded into the cylinder head and in center void of that "donut plate" be a heat coated injector so after or just at TDC it sprays

[Hallman67]

ok, i just skeched somethin up. looking at it on paper, it looks like i could make a working model pretty easily. doubtfull either design would be car worthy but would be fun to see running

[citfta]

Hi Hallman67,

to the forum. I don't want to throw cold water on your idea but I don't believe you will be able to maintain the heat you would need in the engine for this idea to work. A diesel engine works on the same idea except it ignites fuel instead of turning water to steam. They have a very high compression ration of usually over 20:1 instead of the lower ratio of a gas engine. This high compression is partially for the same reason you have said. It helps to heat the air. However it is not enough to even fire a diesel in cooler temperatures without some form of extra heat put into the engine. So diesels use glow plugs or airflow heaters to help get them started and they use quite a bit of power from the battery besides the cranking power needed for the starter.

If you had glow plugs or some form of continuous heat to offset the cooling effect of the water turning to steam you might be able to get your idea to work. I would suggest you study how much heat it takes to convert water to steam. You see when the water turns to steam it absorbs a lot of heat and that will cool down your cylinder a lot. So the compression has to overcome the cooling and still build enough heat for the next cycle. An easy way to try your idea would be to get an older junk diesel car and maybe modify the injectors to get them to inject water. You would need to treat the water with something that would break up the surface tension of the water so it could flow through the injectors and the injector pump. Then you could try wiring the glow plugs to stay on all the time and try your idea.

Actually there have already been some inventors that have used a mixture of diesel fuel and water with an emulsifier to allow the water and diesel to stay mixed. They don't run on straight water but they have run on as high as 50% water according to some reports. Good luck on your ideas and keep thinking!

Respectfully, Carroll

[Hallman67]

"I don't want to throw cold water on your idea" <- Great pun, intended or not lol. i suppose i didnt think of the rapid cooling effect from the steam..... though i only have a 20 min wikipedia education in thermodynamics lol,

The plan was to get a junk diesel and experiment, up the compression via longer piston rods ect. once i have sufficient resources. As said before its just a cool idea that popped in my head, only 1 of many that i picked outta my notebook.

OH btw, thanks for the welcome