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Cummins 2 stroke Diesel developed for military

Melensdad

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This looks interesting.

Cummins developing revolutionary new diesel engine for U.S. Army | Fox News


VIDEO at link >>> https://www.youtube.com/watch?v=JoQkTIfAB2U

. . .

The Advanced Combat Engine (ACE) project is a joint venture between Cummins and California-based Achates Power, who has designed an opposed-piston engine that works on a two-stroke combustion cycle and eliminates the need for a valvetrain.

There are two pistons in each cylinder that compress the air-fuel mixture between them. The movement of the pistons exposes intake ports at the bottom of their strokes, while a direct fuel injection system adds ads diesel as the piston heads come together. A series of gears connect cranks at the top and bottom of the engine to a common output.

According to Achates, eliminating the head reduces heat loss and improves the thermal efficiency of the engine. Cummins says it is targeting a 21 percent reduction in thermal rejection, along with a 50 percent increase in power density and a 13 percent jump in fuel efficiency compared to engines currently in use.

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mla2ofus

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Makes me wonder if Detroit diesel is pursuing this design? After all they were the top 2 stroke diesel maker.
Mike
 

Melensdad

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Given the added efficiency, I also wonder if there are civilian car/light truck uses for this technology in the near future?

Obviously it would have to be able to pass emissions certification for civilian uses but since diesel is already economical and efficient, a 50% power increase combined with a 13% increase in efficiency would make for an impressive vehicle engine that could run long distances on little fuel.
 

mla2ofus

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Did some research on it and it sounds interesting. They're also working on a 2 stroke compression ignition gas powered one.
Mike
 

300 H and H

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Fairbanks Morris built engines with this general design back before WW2. They were large stationary engines, and they were used on large electrical generators. I remember running across several of them in salvage yards, and at first wondered why any engine would have an upper and lower crankshaft..

There is also another engine design out there with twin opposing pistons in the same bore. It is called the "Opoc" I believe. Here is that one...

[ame="http://www.youtube.com/watch?v=9Gcaoel6QFY"]Opposed Piston Opposed Cylinder Engine - YouTube[/ame]

Regards, Kirk
 
Given the added efficiency, I also wonder if there are civilian car/light truck uses for this technology in the near future?

Obviously it would have to be able to pass emissions certification for civilian uses but since diesel is already economical and efficient, a 50% power increase combined with a 13% increase in efficiency would make for an impressive vehicle engine that could run long distances on little fuel.
There is an aircraft power plant with this opposing cylinder concept. I’m not aware of any airplane flying with one installed. A company was in the development phase. All EMD locomotives are two stroke Detroit engines unless they have been repowered with a Caterpillar engine.
 
Emissions is what killed the 2 stroke Detroit.
Mike
Modern EMD locomotives are to this day two stroke. As a result they use more fuel than General Electric locomotives which are four stroke. I owned a 8V71 Detroit in a bus once. I think it had a roots blower that was gear driven, some locomotives also have roots blowers.
 

300 H and H

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There is an aircraft power plant with this opposing cylinder concept. I’m not aware of any airplane flying with one installed. A company was in the development phase. All EMD locomotives are two stroke Detroit engines unless they have been repowered with a Caterpillar engine.

Junkers Jumo 205​


WW2 and Diesel to boot all in an airplane engine.


you need to hear one run!
 
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tommu56

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Most big ships have 2 stroke engines in them too they actually stop the engine and start in in reverse to put the prop in reverse.
 

mla2ofus

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Modern EMD locomotives are to this day two stroke. As a result they use more fuel than General Electric locomotives which are four stroke. I owned a 8V71 Detroit in a bus once. I think it had a roots blower that was gear driven, some locomotives also have roots blowers.
Contrary to what some folks think a 2 stroke diesel will not start without a blow. Don't know about all but I know a 2 stroke detroit won't. The blower is necessary for air exchange in the cylinders. The reason small 2 strokes don't need a blower is because it uses movement of the piston in the crankcase to effect air exchange in the cylinder.
 
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