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Workable opposed piston engines

werepossum

werepossum

Elite Member
http://www.engineeringtv.com/video/Two-and-Four-Cylinder-Single-St

I thought this was pretty interesting. Although several groups are working on this, Monolith engines has several working models. For those who don't know, opposed piston engines use two pistons in one cylinder, working against each other. Vibration is almost completely eliminated, less space is used, and in Monolith's versions the engine block becomes an extrusion rather than a casting. They are claiming 300 horsepower in a 70 pound engine. The design also greatly reduces piston and cylinder wear since there is very little (no theoretical) side thrust. Monolith has even extended the concept to four pistons in one cylinder, producing a true single stroke engine.

The engines can be designed for any combustible fuel and are well suited to serving in engine-generator combinations, which makes them perfect for hybrids and for military vehicles. And efficiency is around 40% - which is roughly a 15% increase over a typical 35% efficient automotive-sized engine.
 
Interesting. I've always wondered considering the advancments in computing power over the last 30 years why the internal combustion engine has been virtually the same over the last 100 years.
 
Opposed piston engine technology has been around for quite some. Fairbanks-Morse manufactured 10 cylinder opposed piston diesel engines that were used on Naval vessels for emergency power generation.
 
Inform the Chinese to begin manufacturing immediately! Begin training India to support the engines!

Americans eat more cheezburgers!
 
It would be more convincing if they had one operating. I'm not going to demonize existing tech until I see more.
 
At first I thought you were taking about the radial piston engines used in airplanes but on seeing the film this is quite a bit more.

Would love to see one of these in my Prius in the not too distant future. I hope these guys have some air-tight patents on this!
 
Yeah, that is a very cool story, kudos for posting that!


Very interesting, although the name needs work. No where near as dirty sounding as a Wankel rotary engine.
 
There are other motor technologies out their that look promising but yet none of them are going to make it.

LINK is already in use by the Russians(which supposedly stole the idea)
 
Thump553 said:
At first I thought you were taking about the radial piston engines used in airplanes but on seeing the film this is quite a bit more.

Would love to see one of these in my Prius in the not too distant future. I hope these guys have some air-tight patents on this!
Click to expand...
They do have some patents, but can't patent the idea; as Londo says, opposed-piston engines have been around for some time, usually as stationary power units. Opposed cylinder engines almost have to have dual crankshafts and must have equal loadings on each piston to avoid heavy vibration and wear, which limits their applicability to standard mechanical drive systems. Either the engine has to have gearing to get back to a single output, or a very complicated transmission must be designed. Either way, there is added complexity, weight, and expense. However, when the engine is decoupled from the drive, combining the output of two small electrical generators is much more simple and also offers the possibility of 50% power (with added vibration) in case of generator failure, important for military and emergency power applications. This also makes it ideal for plug-in hybrids where the I.C. engine merely recharges and replaces the output of the battery, as an opposed engine with dual generators can be significantly lighter and more compact than a conventional engine and generator.

I'm not sure the four piston single stroke concept is patentable, but it might be. Certainly I've never seen one even mocked up.

As far as running, Monolith was supposedly going to run a 1.2 liter engine in May. I've not seen anything of that, so I don't know if the test was a failure, canceled for lack of funds, or what. These engines are complicated and really need sophisticated controls with pressure sensors and flow mass sensors to work properly, but in today's world all automobile-scale I.C. engines have those things anyway for mileage and emissions control.
 
Dulanic said:
It sounds like it should work well... I am curious why this hasn't been used before.
Click to expand...

I don't have audio, so I googled "opposed piston engines", looks like they've been around for over 100 yrs. Although I suspect these guys the OP linked have some improvements.

Fern
 
Fern said:
I don't have audio, so I googled "opposed piston engines", looks like they've been around for over 100 yrs. Although I suspect these guys the OP linked have some improvements.

Fern
Click to expand...

I'm guessing it never took off due to being hard to engineer. Advances in computer tech have made designing and testing so much easier and cheaper. I wish Tesla was alive today.
 
werepossum said:
They do have some patents, but can't patent the idea; as Londo says, opposed-piston engines have been around for some time, usually as stationary power units. Opposed cylinder engines almost have to have dual crankshafts and must have equal loadings on each piston to avoid heavy vibration and wear, which limits their applicability to standard mechanical drive systems. Either the engine has to have gearing to get back to a single output, or a very complicated transmission must be designed. Either way, there is added complexity, weight, and expense. However, when the engine is decoupled from the drive, combining the output of two small electrical generators is much more simple and also offers the possibility of 50% power (with added vibration) in case of generator failure, important for military and emergency power applications. This also makes it ideal for plug-in hybrids where the I.C. engine merely recharges and replaces the output of the battery, as an opposed engine with dual generators can be significantly lighter and more compact than a conventional engine and generator.

I'm not sure the four piston single stroke concept is patentable, but it might be. Certainly I've never seen one even mocked up.

As far as running, Monolith was supposedly going to run a 1.2 liter engine in May. I've not seen anything of that, so I don't know if the test was a failure, canceled for lack of funds, or what. These engines are complicated and really need sophisticated controls with pressure sensors and flow mass sensors to work properly, but in today's world all automobile-scale I.C. engines have those things anyway for mileage and emissions control.
Click to expand...

When it needs electronics to run, it will get interesting.
The more requirements need to be fulfilled for stable operation, the better.

But i do think it is better to abandon I.C. engines all together.
 
Interesting concept but a working model is different from a road trial! They are a long way from some kind of real working motor vehicle that can drive 200,000 miles. Looks like too many moving parts and too much stress. If the parts are traveling further and have more joints, then it just adds to the complexity. Still might need to cool the engine block.
 
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William Gaatjes said:
When it needs electronics to run, it will get interesting.
The more requirements need to be fulfilled for stable operation, the better.

But i do think it is better to abandon I.C. engines all together.
Click to expand...
I think these things would definitely need electronics and computer controls to run, especially the single stroke models. But even with the two piston/cylinder two-stroke models, balance is more important than with conventional engines because there are more parts and pivots.

I do think fuel cells will eventually replace I.C. engines because of the greater maximum efficiency. As resources get more scarce, this will become more important. In the mean time, one thing I.C. engines do better than fuel cells is to switch fuels. There is no practical fuel cell equivalent to modifying a diesel engine to run on alcohol, for instance, or a gasoline engine to run on biodiesel.
 
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