Now THIS is Engineering...simply

[Jr ///M5]

The applications are unlimited!


Saving the World Two Strokes at a Time



This is no wimp engine.
It's a two cylinder with four pistons delivering 300+ Horse Power
It's extremely small and very efficient and is presently in use in test applications
The configuration below is equivalent to a extremely ballsy four cylinder engine
When doubled, it's an extremely ballsy 600+ H.P. engine




It’s called OPOC (Opposed Piston Opposed Cylinder), and it’s a turbocharged two-stroke, two-cylinder, with four pistons, two in each cylinder, that will run on gasoline, diesel or ethanol. The two pistons, inside a single cylinder, pump toward and away from each other, thus allowing a cycle to be completed twice as quickly as a conventional engine while balancing it's own loads.


The heavy lifting for this unconventional concept was performed Prof. Peter Hofbauer. During his 20 years at VW, Hofbauer headed up, among other things, development of VW’s first diesel engine and the VR6.
The OPOC has been in development for several years, and the company claims it’s 30 percent lighter, one quarter the size and achieves 50 percent better fuel economy than a conventional turbo diesel engine.
They’re predicting 100 MPG in a conventional car.

For a good demo, See:
Watch "Opposed Piston Opposed Cylinder Engine" Video at Engineering TV



I'll have two please....600hp??? Note to self, buy stock in tires.

I just copied and stuck the contents here, the video is interesting, 18 months out from production, courtesy of the US Army. At 100 miles to the gallon, gas will soon be $15 a gallon. Thought you might enjoy this...
JR

[Bimmer Nut Ed]

Very interesting stuff, very cool design. But that video is from 2008. Where are these motors now! We need'em.

I think Jr is secretly running one of these in his E34. That's how he keeps the engine compartment so clean. It's really a non functional engine he has under the hood, he has an OPOC in the glove compartment doing all the dirty work "so to speak"! lol

[Ross]

I don't get it. Two pistons(and four con rods) for a given displacement. What does it matter if the forces are acting on one piston or two?
What am i missing?

[Tiger]

I think it is the timing difference... all current engine relies on one piston firing at a time... and other pistons following. This engine relies on two pistons force at the exact time so double the torque at that given moment.

With current engine, one end act as a stop and pressure forces the piston down. This engine because it is horizontal and both pistons move, it has much less resistance to exert the kinetic force.

Again with timing... with current engine... one fire after another and start over agian... in 4 cylinder engine... that is 4 cycles to produce all the power of the engine. New engine... being two fired a the same time... even though it is 4 pistons... only need 2 cycles to produce the same power.

I think it all adds up. to less friction and more power harnessed... Having not read through the whole thing... I really wondered what is the efficiency of this new engine... classic engine is only like 22% efficiency... other are lost to friction and heat. Diesel is higher... I think like 30%... don't quote me on exact figure...

[Ross]

I think it is the timing difference... all current engine relies on one piston firing at a time... and other pistons following. This engine relies on two pistons force at the exact time so double the torque at that given moment.

With current engine, one end act as a stop and pressure forces the piston down. This engine because it is horizontal and both pistons move, it has much less resistance to exert the kinetic force.

Again with timing... with current engine... one fire after another and start over agian... in 4 cylinder engine... that is 4 cycles to produce all the power of the engine. New engine... being two fired a the same time... even though it is 4 pistons... only need 2 cycles to produce the same power.

I think it all adds up. to less friction and more power harnessed... Having not read through the whole thing... I really wondered what is the efficiency of this new engine... classic engine is only like 22% efficiency... other are lost to friction and heat. Diesel is higher... I think like 30%... don't quote me on exact figure...

But it's not double. The charge for any given displacement is the same, it's split between two pistons in this example.
The strokes are short so they are claiming 3800 RPM which I suppose is rapid for a truck diesel. Running any engine faster will produce more power. The technology already exists to spin a diesel faster and the double power cyles/revolution of two strokes v four are nothing new.
Moving parts and friction looks to be doubled in this design and lubrication is an acknowledged "challenge".
Looks like a Rube Goldberg contraption to me.
But give me a hefty paycheck from the military I'll be singing it's praises too.

[whiskychaser]

The strokes are short so they are claiming 3800 RPM which I suppose is rapid for a truck diesel. Running any engine faster will produce more power.

Torque on trucks is very low down so revving its head off doesnt give you any more power. Manufacturers put a green band on the tacho and you are supposed to keep within that to get the best performance and fuel economy. On a lot of trucks the green band ends at 1500 rpm.
My own reservations are that the proposed design is too complex, they havent figured out how to lubricate it properly and that with different length con rods it will be unbalanced. Then again, I dont have a degree in engineering

[Tiger]

Truck and diesel are low revving engine. All the torque is at low RPM... I own diesel car. Revving it higher will help you accelerate faster but there is no extra torque at higher RPM. Modern diesel engine overcome the accerleration issue buy extra gears... 5, 7, 9 speed automatic and keeping RPM low. Old diesel doesn't have that extra gear so it is slllooooowwwww, however, we take off so fast at stoplight.

Two stroke diesel you mentioned is dirty polluting engine which will not meet today's emission standard. They are super powerful just like any two stroke gas ATV/dirt bikes.

I don't have degree in engineering but I have alot of mechanical experience... I think there is less overall friction and displacement loss. Friction in modern engine is in piston rings, valves and all gears needed to run the engine... so typical engine is piston rings, timing chain/belt, valve springs, valve guides, valve tappets/hydraulic valve, and camshaft... etc. I don't see crankshaft as friction because you can spin them freely with no piston attached... they really does 'float' and ball bearings really does reduce that friction.

So this new engine has less 'friction' components... in essence.

Second part is displacement... don't quote me on techincal terms... You must understand that there are blow-bys in combustions... when explosion of fuel mixture... some of that energy escaped past the piston rings... so by having two pistons and two sets of rings... less chance of energy escape... I don't know by how much. Valves do leaks too... which is why valve job is important...

I may be wrong but that is my impression and regardless if this engine catches mainstream or not, I have to applaud them for their engineering innovation. We really do need brilliant minds to keep our technology going forward. You don't need to discourage people... but to say, mmm... interesting... I wonder if I can make that run better.

Big time manufacturesr would say no... piece of garbage... old tech is good and we just improve it a little bit and call it new age engine/next generation. It is all marketing.

[BennyM]

Aren't there motorcycle engines from decades past that use this opposing piston setup?

[Tiger]

At first I thought it was like Porsche 911 engine or BMW motorcycle engine... but it is not.

[genphreak]

I really like the way the forces in each stroke are opposed by equal and opposite forces from the cylinders doing the exact opposite. Without the force transferred to the crank-case/hitting a crankshaft bearings, the friction is much lower so no loss/heat. That efficiency alone, let alone eliminating the extra mass of twice the amount of cylinder head (what is left of the cylinder head on this engine is shared by each pair of pistons).. fundamentally brilliant. Junkers or someone built them before indeed- I found this... Opposed-piston engine - Wikipedia, the free encyclopedia

Oh, and it looks like Bill Gates is investing...

Surely all this is 'prior art' though. I guess the techniology around the valves so on are the main advance with this new OP engine.