One stroke or two?

[Sam StonesParticipant @samstones42903]

Q. Is Spain Living in 2050?

I pass this on for pure interest especially for model engineers.

And, since I am excessively long-in-the-tooth, I respectfully advise that I do not intend to engage in discussion.

**LINK**

I did at one time however, consider that a one-stroke engine would simply go bang, then you’d build another.

Cheers,

Sam

[Sam StonesParticipant @samstones42903]

[Kiwi BlokeParticipant @kiwibloke62605]

Pah!

[Michael GilliganParticipant @michaelgilligan61133]

The 37 page patent is downloadable from espacenet:

**LINK**

https://worldwide.espacenet.com/patent/search?q=pn%3DEP3066312A1

One-stroke it clearly is not [as explained in the video]

Interesting it is

Hopefully, Jason will have a model running by the end of the month

MichaelG.

[David AmbroseParticipant @davidambrose86182]

It’s an opposed piston two stroke, but with a “wavy thing” rather than a crankshaft. I can’t imagine it has as much torque as a crankshaft engine.

[Ady1Participant @ady1]

Posted by Michael Gilligan on 11/07/2023 07:10:46:

Hopefully, Jason will have a model running by the end of the month

MichaelG.

[Ady1Participant @ady1]

Posted by David Ambrose on 11/07/2023 07:52:14:

It’s an opposed piston two stroke, but with a “wavy thing” rather than a crankshaft. I can’t imagine it has as much torque as a crankshaft engine.

I think they did a diesel like this in the 30s.

The million views are probably worth more than the engine… but we can hope

[duncan webster 1Participant @duncanwebster1]

Yet another externally blown opposed piston 2 stroke. Life's too short to watch the whole thing, but if it stops with 2 pistons at top centre, and is then left for a couple of days so any trapped pressure leaks away, what pushes the pistons back down the bore to keep them in contact with the wavy thing? The side thrust on the piston things will be a lot higher than on a crankshaft. I won't be investing.

[mgnbukParticipant @mgnbuk]

what pushes the pistons back down the bore to keep them in contact with the wavy thing?

There is a cam groove in the spigot on the "wavy thing" that is engaged by an overhung bearing mounted on an extended gudgeon pin that the face cam rollers mount on. The piston is guided on both strokes.

Suggestion is that it is premix lubricated – how will that tie up with modern emissions requirements ?

Seems like another developmental dead end to me.

Nigel B.

[Peter Cook 6Participant @petercook6]

Posted by Ady1 on 11/07/2023 10:15:02:

I think they did a diesel like this in the 30s.

Napier Deltic? 1940's -1960's.

[Robert Atkinson 2Participant @robertatkinson2]

There was a discussion on a similar desin on here a while ago.

Wavey thing = swashplate

[mgnbukParticipant @mgnbuk]

Wavey thing = swashplate

Are swashplates not flat – this is more of a face cam ?

Nigel B.

[Ady1Participant @ady1]

My own irrelevant opinion is we really should by this stage with micron tolerances and amazing materials have a combustion motor with no more than two moving parts like a wankel type arrangement by now, particularly since we also have such good control systems to back it up, micron cnc machines and high end 3d printing

…but the real world is never as simple as it appears

Edited By Ady1 on 11/07/2023 13:12:33

[Brian GParticipant @briang]

It looks like one of these axial cam engines from 1938 turned inside out.

For fans of golden age science fiction, try "The Moon is Hell" by John W Campbell.  Many years since I read it, but IIRC the astronauts stranded on the moon build a wobble plate engine from parts of their spacecraft.  Pre-www it was several years after reading it that I learnt what this was.

Brian G

Edited By Brian G on 11/07/2023 15:06:15

[JAParticipant @ja]

The Bristol Bus Co. made, fitted, and used a wobble plate axial engine to their buses in the 1930s. It was a success but was dropped by new owners who prefered conventional engines. I don't know why this engine has a complex wavey thing when the optimum piston travel would be simple harmonic motion. A wobble plate would give this. I am sure the video explains all but I cannot waste the time.

When it comes to IC engines there is nothing new under the sun (rather like perpetual motion machines). I expect there is a patent for an IC engine fitted with a condenser to reduce the exhaust pressure.

JA

[duncan webster 1Participant @duncanwebster1]

I think I've just managed to hit the wrong button and 'ignore member' to whoever posted about bristol busses. How do I unignore him?

[JourneymanParticipant @journeyman]

When logged in go to 'My Posts' in the green top menu. This will give a list but also has the option to 'View Ignored Members' click on the (X) alongside the name and it will unignore if that's the term.

John

[old martParticipant @oldmart]

It has potential, but the difficulty will be with the emmissions.

[Michael GilliganParticipant @michaelgilligan61133]

There is brief reference in Sam’s linked video to this installation

… seems it would be rude to not watch it:

.

.

MichaelG.

[duncan webster 1Participant @duncanwebster1]

Posted by Journeyman on 11/07/2023 16:22:55:

When logged in go to 'My Posts' in the green top menu. This will give a list but also has the option to 'View Ignored Members' click on the (X) alongside the name and it will unignore if that's the term.

John

Sorted thanks. Not all that intuitive is it

[Howard LewisParticipant @howardlewis46836]

Opposed piston two stroles are nothing new. The Junkers Jumo was use during WW 2 to power aircraft.

In USA, Fairbanks Morse produced an opposed piston two stroke to power submarines. Post war, the same engine design was the prime mover for diesel electric locomotives.

The Commer TS3 was another, but with the crankshaft beneath the cylinders, drivem by large rocker levers, to make the engine compact (Boxy rather than tall ) The Rolls Royce K Series of 4, 5 and 6 cylinder (And I think the Leyland L60 ) all intended for military use. (The idea was that by altering the mesh of the geartrain coupling the upper and lower crankshafts, to compression ratio could be changed so that the engine would run on whatever fuel could be found as the army moved

The Napier Deltic extended this principle so that thre were three sets of bores, set around the crankshaft, so six pistons per crankpin. In this case the object was to provide a compact power unit. 1650 bhp in an engine only a little longet than a Perkins 6.354.

In these caes the bloower was for scavenging, rather than supercharging.

General Motors produced uniflow scavenge blown two stroles (V71 and V92 Series and the much larger 647 and 701 engines for locomotives ). The 647 and subsequent engines were eventually turbocharged.

If you want really big two strokes, look at the engine that powers the Emma Maersk and her sister ship.

These are turbocjarged two strokes, deliving 108,000 horsepower at 102 rpm. The crankshaft weighs 300 tons, and the cylinder head studs are 14 feet long!

Howard

[duncan webster 1Participant @duncanwebster1]

Posted by Ady1 on 11/07/2023 13:10:17:

My own irrelevant opinion is we really should by this stage with micron tolerances and amazing materials have a combustion motor with no more than two moving parts like a wankel type arrangement by now, particularly since we also have such good control systems to back it up, micron cnc machines and high end 3d printing

…but the real world is never as simple as it appears

Edited By Ady1 on 11/07/2023 13:12:33

Wankel has a very poor combustion chamber shape, so more difficult to get clean burn. Sealing will always be an issue, you've got to seal against 3 faces all at once, and differential expansion means you can't just make it a very good fit or it will either seize or leak at some operating temperature.

Chap I worked with many moons ago had an RO80 he'd bought cheap with blown Wankel, replaced with a Ford V4. It was the only engine that would fit in the space available.

[duncan webster 1Participant @duncanwebster1]

If you go to the Douglas Self technology museum site and look for axial engines, you'll come across the Alfaro engine, which is a dead ringer for this Spanish thing except it had a flat swash plate, so only one cycle per rev. This was pre WW2.

WARNING, if you do go to that site you'll be there a long time. Absolute mine of information

[Howard LewisParticipant @howardlewis46836]

Many years ago, a Russian delegation tried tom interest us in a variable displacement engine ( Variable between 2 and 3 lires ). This was an engine using axial pistons pressing on a swash plate, the angle of which could be varied.

They were also tring to interest us in a reciprocating engine, also of variable displacement, using asecond con rod connected to a camshaft whose angular position could be varied.

When pressed, the engine was a 4 cylinder 8 litre, producing 800 bhp, for a tank.

"How many have you made?" "Oh, we haven't made any yet"

The followinbg day, I terminated a meeting on possible supply of fuel injection equipment, because of of a rigidly fixed mindset.

So there are still some hopeduls out there!

Howard

[mgnbukParticipant @mgnbuk]

Wankel has a very poor combustion chamber shape, so more difficult to get clean burn. Sealing will always be an issue,

Yet Mazda have recently announced a new electric drive hybrid model with a single rotor Wankel engine driving a generator, so can't be that difficult ? Maybe easier with a generator application, as more likely to be constant speed operation ?

Many years ago Norton also sorted tip sealing life on their Wankel engined motorcycles – IIRC they held a large number of patents in this regard & other versions of their engine were used in surveillance drones.

Nigel B.

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