6 cylinder radial variable compression engine (new design)
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Author:  lkcl [ Sun Oct 27, 2019 1:38 am ]
Post subject:  6 cylinder radial variable compression engine (new design)

Hi folks I am designing a new engine, from scratch. - it is effectively a standard 2 stroke however it is six cylinder (double opposed) radial, and it is a variable compression ratio using chain driven TR8 lead screws exactly like on a 3D printer.

Clearly, it could be done mechanically, however the plan is to later do an augmentation using the Dyer 1921 "water injection" patent, which will involve adding a fuel injector as well as a single exhaust valve, and some method of stopping fuel on every alternate stroke. This may therefore require 12 fuel injectors: 6 for fuel, 6 for water.

Leaving that aside for now, initially I need to be able to run up to 6 spark plugs (simple 50cc Briggs and Stratton 0.5in diameter), read off a timing wheel, and, like a 3D printer, drive a stepper motor (NEMA8 5v 0.3A steppers) and also read off a linear potentiometer (in case of stepper skipping).

Does FreeEFI have onboard steppers or can anyone recommend a suitable board to plug into the Adapt9S12X? 6 will (eventually) be needed.

Yes, I do embedded software so programming is not a problem.

One problem: I have absolutely no clue as to what the best (simplest, off the shelf) sensor wheels are, where to get them, or what the best off the shelf electronic spark coils are, or how to drive them. Am currently in Canada.u

The nice thing is however that all of this is entirely being done from scratch, so literally anything can be chosen.

Suggestions welcomed as to what parts and driver boards would work, and where of course the FreeEFI and driver boards can be bought.



Author:  Fred [ Wed Oct 30, 2019 12:59 pm ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

Interesting. For reference for oth4ers: especially: ... erformance
and ... rke_engine

More of a reply later

Author:  lkcl [ Wed Oct 30, 2019 4:20 pm ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

That's the page on 6 stroke engines. Basically 2 of the strokes are a standard *steam* engine, with the water injection flashing to steam and expanding 1,600 times instantly. It also results in cooling and because it used the explosion from the previous stroke to do work it can be 40% more efficient.

Author:  lkcl [ Thu Oct 31, 2019 1:51 am ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

Oh, btw: if you have a (rare) copy of the Bourke Documentary, you'll know that the "contributors" to the so-called engineering "review" on wikipedia is horse poop.

Brad Howell Smith's early prototype which uses the same trilobe cam principle that I am using is independently certified at 205g/kWh (39% efficient). That's before he did the 6 stroke improvements, and it was using petrol, not diesel.

I spoke with him several years ago, he had to fight with the testing company

Author:  lkcl [ Thu Oct 31, 2019 1:59 am ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

(Fred, the moderation is a nuisance, I hit "send" by accident when using a phone. Normally I would edit and carry on but obviously cannot do so. Can I leave it with you to merge these messages as I am dealing with other issues?)

Message continues:

They refused to let him run it at its normal air-fuel mixture of 30:1. They "negotiated" down to 16:1. He had tested it himself at 30:1 and got 190g/kWh. He also told me that a diesel version should do around an estimated 160g/kWh.

Detonation at TDC gives a full clean burn, instantly, and no damage occurs to the sidewalls. This is what the Revetec and Bourke designs both do. It's not rocket science :)

Obviously, full control over the source code is absolutely essential here, to be able to do these kinds of experimental engines.

Author:  Fred [ Tue Nov 12, 2019 12:03 pm ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

Sorry mate, been a busy couple of weeks for me, all approved now. Maybe one more to go then you have a free reign.

Detonation at TDC quite likely to break ring lands and/or crack rings and/or blow the head gasket out by breaking the firing ring, I would think. Granted it's worse BTDC, but still, a sharp shock is not good either way.

Petrol at 30:1 without being stratified is next to impossible to ignite, too. 16:1 easy enough. The burn gets ultra slow the leaner you go, so that wouldn't produce good torque at higher engine speeds.

Link to "engineering review" and/or Bourke doco?

Author:  lkcl [ Tue Nov 12, 2019 2:43 pm ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

hi, no problem.

i know the engineering "review" of the bourke engine very well. putting it politely, it is total nonsense. i have a copy of the extremely rare "bourke documentary" book, brad howell smith's engine also actually works, i have a friend who has done 30 years research into hydrogen intake injection, and brad had a 2 hour intense grilling from experts at shell who confirmed what he knows.

also look up the roger richards youtube videos, you do not see his reproduction engine blowing up. what you see instead is him running the engine at full power using the LOW setting of a snowmobile carburetor.

rings and the head only blow up if you are stupid enough to throw in a quotes STANDARD quotes amount of fuel. why? because a huge proportion of that fuel *does not get burned*.

for detonation designs it is essential to only put in half the amount of fuel because it is more efficiently burnt and will clearly produce more power (hydrogen-oxygen burn produces eight times more power than carbon-oxygen burn).

when cranking in the top to increase the compression ratio i will switch over to diesel (or more likely, stove oil because it will not have additives).

lead bromide additives were thrown in to stop detonation at TDC rather than work with it. this slowed the burn down, which in turn causes damage to the cylinder wall, keeps the airfuel mix in the "carbon oxygen" burn phase (25 to 75 ft per second) which is why you get flames out the exhaust ports.

historically, "everybody knew" that the otto cycle was inefficient. "everybody knew" that something else much better would come along.

then world war 1 broke out, then we had the great depression, then world war 2, and the mass production "locked in" 2 stroke and 4 stroke crank designs.

the innovation and research basically stopped.

so yes, the "reviewers" on wikipedia are completely clueless. there are several working detonation engines out there, and that's what i want to experiment with.

Author:  lkcl [ Tue Nov 12, 2019 4:55 pm ]
Post subject:  Re: 6 cylinder radial variable compression engine (new desig

Fred wrote:
bThe burn gets ultra slow the leaner you go, so that wouldn't produce good torque at higher engine speeds.

that's what the hydrogen injection is to compensate for. bill ross, my friend's father, is one of the world's leading experts on electrolysis. if you google the pepsi fleet hydrogen article, that was his technology (blatantly ripped off by his "partners").

also, the whole reason why an open ECU is needed is to have full control over the parameters. this is chemistry and engineering.

so yes, burn is slow when lean... *at low compression ratios* (particularly without oxy-hydrogen gas injection added through the air intake). therefore, logically, do not use that combination! :)

with full control over the compression ratio, alongside RPM sensors etc this is perfectly possible to avoid the "ineffective" combinations.

somewhere online there is a lotus variable compression ratio demo. you can see that they only use low compression at low RPM and load, and, conversely, go into diesel fuel injection ONLY at high RPM and load.

it is a hell of a lot more complex than a simple 2 stroke or 4 stroke, and is exactly the kind of thing i love experimenting with.

basically, 2 stroke and 4 stroke engines are 1900s technology that has remained static since the first world war.

Fred wrote:
Link to "engineering review" and/or Bourke doco?

the bourke documentary booklet is extremely rare, now, there are still copies available on amazon (btw please do not buy from the guy with the bourke-documentary website).

the wikipedia page on the bourke documentary, the "reviewers" are unfortunately ignorant of the required combination of mathematics, physics, chemistry and engineering. i began adding information from the documentary booklet: one of the known wikipedia-abusive "admins" got involved, seven years ago, and i was forced to stop contributing to the page. finally after several more years the "review" was correctly classified as "opinion" rather than fact.

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