[ysjoy]

ICYMI: From The Drive

INNengine of Granada, Spain had produced a opposed-piston engine that packed a pretty powerful punch in an extremely tiny package.There's no cylinder head in this motor. Also no crankshaft, no camshaft, and no valves. That's why it's no surprise that this engine tips the scales at just 85 pounds. Somehow, it still produces 120 horsepower with just half a liter of displacement, thanks to what the company calls a single-stroke combustion cycle.

Despite having four cylinder banks, the INNengine (depending on its configuration) actually has eight pistons. This is because the engine is an opposed-piston motor, meaning that each piston's compression stroke is performed against a second piston placed in the same cylinder bank rather than a static cylinder head. It still only has four combustion chambers, though, which means it sounds similar to a four-cylinder engine.

There are no connecting rods to be seen in this motor (at least not in a traditional sense). Instead, the pistons sit on rollers that ride against a lobed circular plate which can be adjusted to affect the engine's timing and compression ratio. As the lobe reaches its peak, the piston rushes towards top-dead-center where fuel is directly injected into the cylinder and a spark plug ignites the compressed air-fuel mixture.

https://www.youtube.com/watch?v=-evh...e=emb_imp_woyt

The mechanical configuration also allows for better engine balance. That means typical drawbacks of an internal combustion motor (often referred to as noise, vibration, and harshness) are minimalized.

Once combustion happens, the piston is pushed back against the plate and forces the plate to rotate. This motion is synced between each half of the motor via a shared shaft—meaning, no extra timing components. Both pistons in the same cylinder bank mimic one another's movements almost exactly.

When the pistons reach the bottom of their strokes, a respective intake and exhaust port is uncovered. One piston is timed to reach bottom-dead-center slightly prior to the other, this allows the exhaust gasses to escape out of the exhaust port and create a vacuum inside of the cylinder—this technique is called scavenging. Fresh air is then pulled in via the intake port as the combustion byproduct is expelled. This effectively gives the pistons double duty, performing the work normally handled by valves in a typical combustion engine—which means that the common drawback of direct injection, carbon-laced valves, is a thing of the past.

Power is also output at both ends of the motor, meaning that a gearbox could be connected to either (or both) end of the motor to put the power to a vehicle's wheels.

Source: The Drive

[RahulNagaraj]

Spanish company - INNengine, has developed a unique engine which is said to be tiny yet powerful.

According to reports, the new engine comes in the form of a 500cc unit and has a single-stroke combustion cycle. The unique one-stroke engine weighs just 85 pounds (38.5 kg) and produces around 120 BHP.



The engine doesn't have a cylinder head, crankshaft, camshaft or valves. It does have four-cylinder banks, though totalling up to 8 pistons. The INNengine unit comes with opposed-piston motors - two pistons are placed in one cylinder bank, with the compression stroke of one being against the second, eliminating the need for a static cylinder head. Even with the unique piston arrangement, the engine has four combustion chambers, making it sounds like a conventional 4-cylinder engine.

Also, instead of a connecting rod, the pistons' movement is via a lobbed circular plate, which can be adjusted to change the engine timings and compression ratio. The spark plug and fuel injectors are placed in the middle of the cylinder bank.

https://www.youtube.com/watch?v=cUnf80kC7lg

The lobbed circular plate is arranged in such a way that one piston reaches the bottom dead centre slightly prior to the other. This helps uncover the intake & exhaust ports. The exhaust gases escape and create a vacuum inside the cylinder, sucking in fresh air from the intake port.

INNengine admits that the engine does have a combustion and exhaust cycle, technically making it a two-stroke engine. However, the company stated that the 'one-stroke engine' was suggested by an external ICE institution, which they found catchy and have stuck by since.

https://www.youtube.com/watch?v=-evhsWLWlkY

To demo the engine, INNengine installed it on a Mazda Miata. However, the company is targeting the 'one-stroke engine' towards the EV segment as a range extender.

Source: TheDrive

Link to Team-BHP news

[Gamemaztr]

No matter, this will be a revolutionary engine. This will be a major boost to the Hybrid Car Industry.

[PaddleShifter]

Two stroke engines need an additive “mobil oil” back in the 90s. Will this require additives in some manner?

If this engine can be fuel efficient in real world, its good news for the Hybrid and EV segment as an added hardware with low poolution, to extend the range.

[aslampr07]

Originally Posted by RahulNagaraj

INNengine admits that the engine does have a combustion and exhaust cycle, technically making it a two-stroke engine. However, the company stated that the 'one-stroke engine' was suggested by an external ICE institution, which they found catchy and have stuck by since.

The 'One Stroke' is merely just a brand name for the engine. If anyone interested to know more about this I would recommend watching the below video.

https://www.youtube.com/watch?v=9I0_3qFmPUM

[ComboCutter]

The product sounds like snake oil and even if it really holds merit is a decade too late to the scene.

Its marketing and merits have been debunked to a large extent here -

https://youtu.be/9I0_3qFmPUM

Tldr: they used a supercharger to achieve the 120bhp and have not mentioned at what rpm it did achieve it. There literally has been no supporting data or even their own published data for such claims. It is all hype and marketing.

Also one stroke engine marketing is very dubious and from a engineering stand point really funny.

[ProLearner]

Originally Posted by PaddleShifter

Two stroke engines need an additive “mobil oil” back in the 90s. Will this require additives in some manner?

If this engine can be fuel efficient in real world, its good news for the Hybrid and EV segment as an added hardware with low poolution, to extend the range.

As much as I understood from the videos, this is actually a two stroke, not 1 stroke engine. But this does not require the oil, and hence they are calling it 1-stroke to differentiate this from old 2-strokes. This does not have the gas guzzling and oil burning characteristics hence it is better.

[greenhorn]

This looks very similar to https://radmaxtech.com/ in principle. From what i understand this sort of stuff is always being experimented on, having something that runs reliably and can be mass produced is the challenge

[turbospooler]

I saw this video some time back and was impressed.
It was an Aha! moment video, which prompted me to ask if it was so simple, why was this not done before.
Also, I believe the way the external ICE Institution is calling it 1 stroke is due to the 2 strokes being divided in the 2 sides of the "cylinder banks". So, 1 stroke at each side.

[Jeroen]

It certainly is a very innovative and creative invention. Will it become successful? Well, the truth is that since the invention of the internal combustion engine we have seen very few successful major changes to the more than a century old piston crankshaft concept. The jet turbine is one that is completely different, but has never been successfully used in cars. Only a few trucks and that never became a succes either.

We have seen designs such as the Wankelengine and the Scuderi engine. Promising just like this new engine all sorts of advantages over traditional engine design. The Wankel enige was pretty much a disaster when it was first introduced. It used more engine oil than fuel. Later versions did better but it has enjoyed only a very moderate level of succes.

With the Scuderi engine, which was supposed to vastly increase overal engine performance, it never made it past one test bed engine.

Time after time somebody claims a break through in engine design. But what might look like a great idea on paper, might not be able to work in practice.

I can only think of one successful major design change to traditional piston/crankshaft design and that is the Atkinson engine. Not the ones with some fancy valve timing, but the ones, that mechanically alter the compression and power stroke.

The principle was invented by Atkinson in 1882. The actual commercial viable Atkinson engine did not hit the market till a few years ago. Same principle. Looks good on paper, but very difficult to get it perform in real life. Only on a hybrid drive line can the Atkinson engine deliver as the E motor overcomes all of its shortfalls.

So whilst I wish these inventors all the best and congratulate them with their new engine design I am not holding my breath yet. We will not see this engine commercially in any car for some time to come.

Jeroen

[PreludeSH]

Interesting for sure. Its like a boxer engine with heads removed and merged into one common head The camshafts are acting directly on the piston too
You still need more air and they should build a bigger cylinder engines. Have they shared the torque curve anywhere. Not sure how it can move from standstill.

[vedirah]

I was very intrigued when I read the title of this post, but once I watched the official video to see how it works, it was immediately clear to me that this is just another form of a rotary engine with additional steps. And it comes with the same disadvantages that the rotary comes with - very low mechanical advantage coefficient. It simply wouldn't have enough torque.

While in theory it is capable of producing a lot more power than a traditional 4 stroke engine, but that also happens at a very high rpm which comes with its own challenges. At high rpms, inertia becomes a major issue. Not just from a vibrations point of view, but also from a control point of view. By design, the rollers must be as frictionless as possible, but that itself means at high rpms you don't have enough engine resistance, which means wonky accelerator pedal feel. Four stroke engines have their own problems at higher rpms (primary and secondary vibrations, noise, loss of power), but at least they have predictable response.

Ingenious, but not a practical solution.