The evolution of the internal combustion engine

The next step along the evolution of the humble reciprocating internal combustion engine.

Category:

Autos & Vehicles

Tags:

• engine
• SPEC
• square-piston
• reciprocating
• internal
• combustion
• kiwi

[smvuy]

is this a two stroke?

[nztankman]

Yes this is a two stroke but has 4 stroke characteristics - less noise, exhaust emissions and vibration. Being 2 stroke it has an enhanced power to weight ratio.

Thanks for your interest.

[chilt02]

I'd help you build it though I work in a machine shop but only because i want to see the thing shake the shit out of itself

[nztankman]

There have been 3 working prototypes of the engine built. A large diesel, a small diesel and a petrol engine. The petrol prototype has done in excess of 500 hours during testing with no appreciable cylinder wear or seal issues.

The engine does have a conrod so in many respects it not a big departure from existing technology, just has 2-stroke power with 4-stroke emissions (exhaust, noise and vibration).

[nztankman]

I'd be keen for your help to build it.

[chilt02]

can't work, but nice try, other than the obvious flaw with your crankshaft connection (the pistion wouldn't follow it unless the piston was constantly loaded downwards on the piston) the next monumental problem is heat dissipation on the added surface area on the cylinder walls would cause uneaven expansion and contraction thus affectiong the seal, AND operationg efficiency resulting in extreme premature wear. I'd give it about 3000 revolutions in a combustion test before it cock-eye'd andseized

[nztankman]

Hey thanks for your comments. The engine reciprocating motion occurs very much the same way as an existing engine, the piston is connected to the crankshaft by a connecting rod. The main difference is that the crankshaft runs within the piston which means that the engine can re-use lubricating oil as a 4 stroke does rather than it being combusted as a 2-stroke does.

[pdgeman]

I can't see this thing lasting too long. The square piston... ah screw it.

[NearAbbeyRoad]

Why square piston? Round is easier to machine. Cylinders and piston are used like this by pattakoncom. Do a search on Youtube for them. Working models.

[Tjita1]

Why is that evolution? I though most of the universes scientists agreed that a round shape is ultimate to contain pressure? Guess why pressurized aircraft are round. I can see no purpose of this construction what so ever. It's just more complicated, more prone to internal wear, harder to seal, and also the combustion should in theory be less efficient as it has to reach out to the corners of the chamber. There is a reason why we've had round cylinders for the last 100 years or so.

[NearAbbeyRoad]

This setup gives small and light packaging giving a high power/weight ratio. Ideal for fixed speed genny applications for hybrids.

[NearAbbeyRoad]

@nztankman

A disk yolk would eliminate the con-rod and make it more efficient.

It can be round cylinders. Two inline opposed cylinders one long piston in both cylinders, with the disk yolk between the cylinders. Not a new idea. In this setup it is fine for small, simple, engine applications.

[mwhite112393]

How would this work 'better' than a cylindrical piston? A square is harder to seal, you know...

[Sqquiid]

thats pretty much exactly the same as we have now, just different con rods, and thats wouldnt exactly work, cause you wouldnt get enough power out of a stroke that short, if that could work, that wouldnt be the furture, you still need every basic part like the camshaft and valves and all that, doesnt really solve anything in my eyes, sorry

[steamnut2008]

It looks like a round piston would work just as well. I don't see the advantage of the square piston, and see many disadvantages, line the difficulty of getting the rings to spring out and seal against the cylinder wall.

[futuristictech]

who design the square pistong rings? i would like to know if they need new tools to create the compression seals.

[smvuy]

Thank you, what about thermodinamic efiiciency? how huch of the chemical energy is translated in kinetical energy?