btlbcc commented on November 25, 2014
Fairbanks-Morse (if I recall correctly) made an opposed-pistol diesel engine (possibly a copy of the German engine referred to. I don't know how they kept the upper piston from filling up with oil from the upper crank bearings, but apparently there was a solution. We had a couple them (surplus, no doubt) in the power plant at the college I attended. They also had a couple of Ames Uniflow steam engines. The steam engines were quiet - you could hardly hear them running; the opposed-piston diesels were extremely noisy - the sound seemed to come out through the engine block at the point where the pistons met. Both types of engine were generating about 300KVA. They tended to run the steam engines during the winter (the exhaust steam was routed through the heating system) and the diesels during the summer, when they shut down the boilers. It's been a while, but I believe that due to extensive campus expansion, that they have shut down the power plant and gone to the local electric company, replacing the 150PSI power boilers with 15PSI heating boilers. Progress may be good, but it's not always so interesting....
artoriusthebear commented on October 21, 2014
Many of you guys brought up some good comments. As someone who is designing my own engine; and thus I tend to find the flaw in all other designs. I find this one pretty interesting.
*Oiling: Somebody mentioned that the oil will fill the cylinders when the engine isn't running. But That would mean that all radial engines and inverted engines would have that problem. So, somehow it has been dealt with.
*Breathing: Somebody mentioned the difficulty in getting airflow through the engine. This really isn't an issue as long as ports are kept to a good size and smooth. Its he same in any engine. And cylinder wall ports always flow better than poppet valves anyway.
*efficiency: I think here there is a lot of questions. So I'm gonna split this into two groups.
*fuel efficiency: I don't see much advantage here.
*Power to weight ratio: Here is where this design is really superior. It isn't however as compact as they claim. The motors they are showing are long-blocks. Thus lacking the fuel injection system, intake plumbing, exhaust system, cooling system, electrics, output shaft combiner, etc. The claim that their 4 cylinder engine is "the size of an modern engine with only one cylinder" is bogus.
So finally: I like the idea, and I can think of tons of uses for it. But I don't see it replacing the tried and true stuff. Just being a special purpose motor for certain applications.
Uncle B commented on March 31, 2013
Compared to the three moving part complete power train electrics? still an internal combustion, so still only 25% efficient, against an electric motor at 99% efficiency. nano carbon super capacitor systems promise high efficiency energy supply for the electrics. Fossil fuel engines epoched by modern Science and technology, belong in the 20th Century American Dream, not the 21st century Global Village realities.
Mr Lama commented on March 16, 2012
How can it be called one stroke because there is only one time firing in total one crank cycle.
Design and thinking very good and interesting.Appreciate it.
If anybody wants to know about single stroke piston engine pls firstname.lastname@example.org ... Its totally free.No business no donation,
Earth is a basket of will and wish where you can find everything just you should have idea..knowledge and ability to get it.
CRC commented on October 09, 2011
All opposed piston engines have some basic problems. There will be oiling difficulties of the pivot points of the bars. Opposed piston engines rip there selves off of scavenging area by trying to suck in air/fuel mixture for two cylinders in the space of one and/or will have very low compression ratios. I see cooling problems. The one-cycle verion makes two strokes (right and left); how is it a one-cycle engine. Most importantly the leverage to stroke ratio is the same as all regular engines (1:2)which causes inherent inefficiency due to too much piston speed and movement which causes a rapid drop in cylinder pressure early in the power stroke. Although compact there is NO logical scientific reason for a substantial increase in efficiency. CRC
RonD commented on September 10, 2011
There will be slap on the cross bar. The have just moved piston slap to a new place. All of the opposed piston designs have poor control of the intake and exhaust timing. Probably a dirty engine from a pollution stand point. An Atkinson type design doesn't look possible so an inherent poor efficiency.
KingDWS commented on September 09, 2011
This is not a new idea. The Germans used this exact setup in WW2 in E or Scnhell Boats. Those were their equivalent of the PT boats. The reason I found out about this is about 30 years ago I came up with this "new" idea that is pretty much identical to the video. Was great until someone pointed out those Germans.
Delphi commented on September 08, 2011
Very interesting concept. More complex mechanical linkage, challenges in cooling and lubrication, as others have noted.
This is a two-stroke engine, though. One cannot charcterize the numbere of strokes based on having multiple pistons. The number of strokes is determined on the basis of any single piston.
RickOsmon commented on September 08, 2011
Only caveat: cannot stack them easily to make an 8 piston design. Possible, but not easy because of exhaust porting. That was the real beauty of Wankel's design. However, 200 HP in a 75 lb package is going to sound really good to the light sport aircraft crowd.
Bert commented on September 08, 2011
Very compact, for the power output. I see a couple of potential problem areas. One is, in the opposed priston design, what happens to the oil when the engine is turned off? In a regular in-line or V design, it drains back into the crankcase. Another is cooling. For such a compact design, you have to get the waste heat out, and I don't know whether water jackets that surround the cylinders are possible here? He did allude to the cooling problem, when he mentioned the extra air pump cylinders needed to force cooling air through the main pistons. Not sure about the efficiency claims, though. I can see higher efficiency in terms of power/weight ratio, but no in terms of Carnot efficiency. At best, a slight advantage because of somewhate reduced friction, and that would be only because of reduced piston slap. But to counter that, you need two crankshafts, so I'm just not convinced in that regard.