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June 27, 2008 8:41 a.m. Xceler8x Reader
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June 27, 2008 9:28 a.m. carguy123 Reader
The animation looks like a Wankel driven by pistons
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June 27, 2008 9:45 a.m. wetpossum New Reader
I dunno. I find it incredibly hard to believe that just by having a funky crank layout one can double efficiency and halve the emissions.
Emissions are usually controlled by the flame propagation and turbulent flow in the head. Making sure that there are no unburned hydrocarbons and whatnot.
In the Otto cycle, efficiency is pretty well determined by compression ratio.
On the other hand, I can believe that it's got good power to weight and size ratio,
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June 27, 2008 11:20 a.m. HappyAndy New Reader
I bet this thing shakes like a mofo!
I can see some advantage to this basic concept because the con rods only move in a single plain, unlike a conventional piston engine, that single plain motion must gain a decent amount of efficency, but all the other parts needed to make it all work together must ofset the gain of that single plain motion. also since the "crank" that conects to the conrods via rollers has three surfaces it would make more sence to make it a six cyl in a hexagon configuration if all three conrods could be made to pass through the middle.
I must say that I have been interested in odd engines ever since I learned how engines work, and I have never seen anything quite like this. I looks kind of like radial combined with rotary combined with steam loco drive cyls.
I wish theses guys more luck that the guys that tried to make the clean two cycle a few years back (orbital engines I think)
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June 27, 2008 11:42 a.m. Salanis Dork
I dunno. If they can cut down the number of moving parts, that always helps. I think that having the pistons not be on a rotating arm could be more efficient. You're not translating power across a trigonometric line.
I don't quite get what's up with the counter-rotating cams though. Since they seem to take the place of the driveshaft, but only one of them could be used to drive a transmission. I also wonder if each set pair of pistons is on a different pair of cams, or if all four cylinders are on the same cams. Looks like all four on the same cams. Hmm... that would limit this design to 4 cyl, but there's nothing wrong with that.
I'll be interested to see if this actually goes anywhere. Seems to have promise, but who knows for sure.
This is very different from a radial engine, though.
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June 27, 2008 12:49 p.m. spitfirebill HalfDork
The filter at work won't let me see the link, but is sounds from the discussion that this is an engine I saw in Pop Mechanics or Pop Scence 30 years ago. I'll have to check it out at home.
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June 27, 2008 2:02 p.m. BobOfTheFuture New Reader
Looks like a Revver. As long as everything is counter-balanced right.
Betcha the throttle response sucks... but once all that mass turns up i bet top end could be interesting
It looks like it will have the same effect as a gyro... sounds cool.
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June 27, 2008 2:14 p.m. Duke Dork
Can you say "frame twist"? Knew ya could.
In aerobatics, they don't call it a torque roll for nothing.
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June 27, 2008 2:16 p.m. mad_machine SuperDork
I can see it being really easy on the conrods and cylinder walls as the pistons ONLY move up and down instead of having some side to side loading as the crank turns.
I do find it really interesting.. and I bet it can be made light enough to have good throttle response too.
just out of curiosity, were there ever any fuel injected radials?
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June 27, 2008 2:32 p.m. GameboyRMH Dork
Looks promising, but what's with the counter-rotating setup? They should be able to run as many cylinders as they want on one big cam-lobe as long as there's space...also they should definitely thin out and hollow the giant cam-lobe thing as much as possible.
Also, I'm thinking it could be possible to swap an existing engine to this kind of setup. You'd just need a shaft with a cam-lobe-thing below each cylinder, and you'd need to replace the pistons with the straight sliding type with rollers in the animation. You wouldn't have the pistons working with each other directly but you'd get a similar effect...mind you the super-long pistons would weight a lot. You'd need a lot of space in the crankcase too.
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June 27, 2008 3:50 p.m. phillyj New Reader
I don't like reading all this stuff. In one word tell me if it will work.
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June 27, 2008 3:57 p.m. Salanis Dork
Yes.
They have functional prototypes, at least one of which has been road tested on a VW based tric.
The counter-rotating setup is the only part of it that doesn't make sense to me. I guess they're connected through gears. Reading their background, the idea is that the force of the bearing pushes down evenly on the two opposed deflecting cams.
Check out their website to get more info. They have CAD images and show a variety of layouts they've been able to achieve.
The 60* X4 layout seems to be their best so far. Presuming they stick to a three-lobe cam, I suppose they could maybe get this thing up to a Star6, but that would be bulky.
The interesting thing about this design is that it generates maximum force about 10 from TDC instead of 90 from TDC like a normal reciprocating engine does.
Of course... radial engines work well in theory too.
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June 27, 2008 5:21 p.m. mel_horn HalfDork
Try this: From the Ecurie Ecosse hauler of the '60s...
http://www.sa.hillman.org.au/TS3.htm
If you have ever seen an old WWI film you might see a "rotary" (original type) where the crank is stationary and the rest of the engine and propellor rotate...
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June 29, 2008 12:24 p.m. phillyj New Reader
mel_horn wrote: Try this: From the Ecurie Ecosse hauler of the '60s...
http://www.sa.hillman.org.au/TS3.htm
If you have ever seen an old WWI film you might see a "rotary" (original type) where the crank is stationary and the rest of the engine and propellor rotate...
this looks something like a boxer engine. Horizontal movement. And the revetc engine looks like they put 2 boxer engines perpendicular to each other, although it is more complicated than just that. It is probably very stable
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June 29, 2008 2:04 p.m. DUTCH 73 tcs New Reader
Try a look at the Napier Deltic engine - 3 cylinders, 6 pistons, 3 drive shafts. http://www.wis.co.uk/justin/deltic-engine.html They were used in high speed patrol boats Dutch
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June 29, 2008 2:13 p.m. 924guy HalfDork
makes sense to me, kind of like making power on both the up and down stroke of the piston. only in this case, its more like two pistons, and effectively one rod...it also seems the counter rotating cranks provides not only a means to drive two more pistons, but also damps the vibratory effects... stack four and you've got your 8 cyl, though i dont think it would work for 6 cylinders..... i don't think the efficiency would quite double though, seems to me it would loose some efficiency, but close enough to call double anyhow... ...interesting stuff...
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June 29, 2008 7:55 p.m. Wowak Dork
You would have to have some sort of planet gear setup on counter-rotational second piston-set, and I can't really see how the counterbalancing would be worth the additional complexity.
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June 29, 2008 8:35 p.m. Twin_Cam Dork
Interesting. I agree with those that say that thing can rev...I'll bet it can rev to the moon. Sweet.
Double fuel economy though? I don't really see how.
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