4-stroke opposed-piston engine development from Pinnacle Engines?

[cRiPpLe_rOoStEr]

Originally Posted by Fingie

how smooth is this design, anyway?

I don't know, but there are claims that it wouldn't require counterbalancing shafts to run smooth.

[Phantom]

I'm not sure if i'm missing something but it would seem that the engine would be less efficient. Looking at the animated pictures above that would just be a high compression 3 cylinder with twice the rotating mass since it has two rotating assemblies. Other than possibly starting possibly being quicker and revving faster I would think a high compression 3 cylinder would be more efficient.

[cRiPpLe_rOoStEr]

Originally Posted by Phantom

I'm not sure if i'm missing something but it would seem that the engine would be less efficient. Looking at the animated pictures above that would just be a high compression 3 cylinder with twice the rotating mass since it has two rotating assemblies. Other than possibly starting possibly being quicker and revving faster I would think a high compression 3 cylinder would be more efficient.

It gets a longer overall stroke-to-bore ratio and has fewer surfaces where the heat could escape. Honestly I'd still be more worried about the sealing at its sleeve valves in order to decrease the oil consumption.

[Lemmy]

Thermally quote efficient, but intertial and frictional losses from 2 x cranks and the gear required to synchronise them will be significant. I suspect there's a reason why such designs have never been mainstream.

[cRiPpLe_rOoStEr]

The opposed-piston layout used to be mainstream for interwar German aircraft, but it was mostly Diesel and 2-stroke. Anyway, considering that a regular 4-stroke also has some inertial and frictional losses from a conventional valvetrain, the dual-crank setup might outweight this perceived disadvantage.

[cRiPpLe_rOoStEr]

Indian company Greaves Cotton, one of the largest independent engine suppliers in India, set a deal with Pinnacle Engines to develop that opposite-piston layout and put it on production. Not sure what would be the first product to feature it, but since many tricycle factories in India resort to Greaves engines it's likely to succeed.

[cRiPpLe_rOoStEr]

Last updates I found were from February. Seems like most of the focus will be toward using this engine with CNG, which is a widely popular fuel in India.

https://www.youtube.com/watch?v=puWIOnCTuSg

http://www.greavescotton.com/php/med...fd4ce602ef.pdf

[kach22i]

From that video looks like some rebranding of catch phrases involved.

I wish them luck.

[cRiPpLe_rOoStEr]

Originally Posted by kach22i

I wish them luck.

They seem to have a good design, and there is a great demand for products that could be fitted with that engine not just on small tricycles and scooters but also on gensets and other stationary devices. It's just a matter of effectively releasing it to the market.

[Shaneajanderson]

I heard recently about something like this, I believe it was Mazda that was experimenting with it. The efficiency was supposed to largely come from the fact that it can run on duel fuel. It's supposed to have a tank for diesel, and one for gas. Depending on engine speed, load, and temperature it's supposed to adjust the mix (and it runs on the diesel ignition cycle regardless). Supposedly It can also run on strictly one or the other, but it's optimum would be while running both.