5-stroke engine

[RayTay]

Has anyone heard of any advances on the 5-stroke engine? Ilmor made a successful prototype about 4 years ago and its looked like it was to be taken up by a major maker.

The engine was invented by a Belgian, Gerhard Schmitz, with Ilmore taking it up. It is petrol and has the thermodynamic efficiency of a diesel. It is also smaller and lighter than the equiv 4-stoke petrol engine, so much smaller and lighter than an equiv' diesel engine. It uses two stage expansion. It looked like all was going then nothing.

It works in banks of three cylinders. It is essentially two power cylinders on the normal 4-stroke cycle, with a larger lower pressure exhaust (expansion) cylinder between them which each power cylinder pumps its exhaust gasses into. The two power cylinders are on BDC but fire at 180 degrees apart from each other. The exhaust of the power cylinders pump into the centre exhaust cylinder, which is on TDC to the power cylinder which are BDC, utilising waste power from the exhaust. Every downward stroke of the exhaust (expansion) cylinder is a "power" stroke making this cylinder a two-stroke cycle cylinder. So, exhaust gas exits the power cylinder and enters the shared exhaust (expansion) cylinder and out to the exhaust pipe via the exhaust cylinder.

With two cylinders you get one power stroke per revolution of the crankshaft. The exhaust (expansion) cylinder adds more power to that one power stroke in each revolution, so still only one power stroke in each rev of the crank. The power strokes of the exhaust and power cylinders are not staggered, they give power at the same time. Having a V6, (really a V4 with two exhaust (expansion) cylinders), the power cylinders on one bank can exhaust into the expansion cylinder on the other bank, staggering power strokes in crank revolutions.

There are many advantages, no exhaust manifold for one. It is so simple. Lighter and smaller as well. I think Ilmor said they would get 185 HP per litre, with 130 HP gained on a 700cc test engine. A turbo could even be fitted on the exhaust to increase efficiency yet again. I can't see why it has not been taken up. All it is, is an extra cylinder and camshaft over a normal 4-stroke engine



http://www.ilmor.co.uk/capabilities/5-stroke-engin...

https://www.youtube.com/watch?v=-yo6xuVS7tg
https://www.youtube.com/watch?v=u0uPmrSRM7w

Edited by RayTay on Sunday 20th November 10:32

[Jimbo.]

Because the internal combustion engine is living on borrowed time?

[Puddenchucker]

Sounds similar, in principle, to a compound steam engine where once the steam has done work in a high pressure cylinder it's then fed to a low pressure cylinder to extract more of its energy.

[RayTay]

Puddenchucker said:

Sounds similar, in principle, to a compound steam engine where once the steam has done work in a high pressure cylinder it's then fed to a low pressure cylinder to extract more of its energy.

Exactly.
It is similar to using a turbo in capturing wasted exhaust energy, but turning it directly into HP at the crank, rather than indirectly by forcing more oxygen into cylinders for greater combustion as a turbo does. It must be far more reliable than any turbo and takes up less space overall. The two power cylinder will be exactly the same as any 4-stroke cylinder. The centre exhaust cylinder is passive needing no maintenance whatsoever. There is no combustion in it - nothing like that.

I can see that manufactures will not like spending millions/billions on technology that is nearing the end of its lifespan. But the 5-stroke is so easy to build and gives so much more. No new technology is needed, all existing, and no new manufacturing techniques and plant either, and it is easily converted into a range-extender - where the market is heading.

Paying royalties to the inventor puts them off. For e.g., if all the advances in the wankel were all rolled into one engine it would be different to what we have seen and a highly competitive and reliable engine. However the many royalties paid per engine for many different advances would be substantial maybe to make it not financially viable to produce. Sometimes it is not technology holding matters back.

Edited by RayTay on Saturday 19th November 14:56

[RayTay]

James Watt held back the steam engine for about 10 years because of royalties.

"After the expiration of Watt's patents, not only was there an explosion in the production and efficiency of engines, but steam power came into its own as the driving force of the Industrial Revolution."

https://mises.org/library/james-watt-monopolist

[anonymous-user]

PetrolJosh said:

Puddenchucker said:

Sounds similar, in principle, to a compound steam engine where once the steam has done work in a high pressure cylinder it's then fed to a low pressure cylinder to extract more of its energy.

Yeah exactly that. It's the same principle of "harvesting" what would normally be lost energy.

Combination boilers harvest lost energy of flue gasses,

Thats all I've got.

[RayTay]

GTi_ said:

Combination boilers harvest lost energy of flue gasses,
Thats all I've got.

Condensing boilers, not combination. They are made to condense capturing latent energy in the flue gasses. Combination boilers (combi) combines a heating boiler with an instant DHW water heater. It can be condensing or not condensing.

Edited by RayTay on Saturday 19th November 18:18

[robinessex]

There are hundreds of alternative 'engines' out there, quite a few in ltd production. But nothing yet has outed the good old 'suck, squash, bang, blow'.

For an evenings education

https://www.google.co.uk/search?q=alternative+comb...

[Willy Nilly]

RayTay said:

Exactly.
It is similar to using a turbo in capturing wasted exhaust energy, but turning it directly into HP at the crank, rather than indirectly by forcing more oxygen into cylinders for greater combustion as a turbo does. It must be far more reliable than any turbo and takes up less space overall. The two power cylinder will be exactly the same as any 4-stroke cylinder. The centre exhaust cylinder is passive needing no maintenance whatsoever. There is no combustion in it - nothing like that.

Edited by RayTay on Saturday 19th November 14:56

I've been using turbo charged engines for over 25 years and they are spectacularly reliable

[robinessex]

It's often the electrics that kills off a car these days.

[RayTay]

A point about the 5-stroke is that the centre exhaust (expansion) cylinder is always hot. It is not cooled by an incoming charge. The cooling system has to be up to it to cool this cylinder. Or does it need water cooling and only just lubrication, as there are no explosions in there? If the cylinder is in the water jacket it will also give a quicker warm up time which is an advantage.

Edited by RayTay on Saturday 7th January 11:23

[RayTay]

robinessex said:

There are hundreds of alternative 'engines' out there, quite a few in ltd production. But nothing yet has outed the good old 'suck, squash, bang, blow'.

Many of them are superior to be sure. Why they are not taken up is for many reasons and not because they do not work.

[anonymous-user]

It has been a long time since I did any thermodynamics work but I cannot see that being a particularly efficient way to extract waste heat from the exhaust, and from a manufacturing point of view a turbocharger gives far more flexibility in terms of re-using the basic engine design for NASP and turbocharged variants. As someone has stated, turbochargers are extremely reliable in a properly serviced car.

You're also only getting one power stroke per crank revolution, alongside the out of balance forces of a 3 cylinder engine so it'll be as rough as a badgers arse unless you use two of them in an I6 and V6. Even then you'll only have power strokes 180 degrees apart, and you've left the economy minded marketplace behind.

[RayTay]

This is not an alternative engine by Ricardo, just using a mechanical turbo, assisted by an electric turbo to downsize an engine from 2 litres to a 1 litre 3 cylinder, with the same performance. It has a combined starter motor/alternator, eliminating a separate starter motor. The starter motor/alternator also reclaims kinetic brake energy and stores the energy in supercapacitors to run the electric turbo. The supercaps store electrical energy quickly and give it off quickly for the electric turbo boost when needed. The starter motor/alternator is in the normal alternator position starting the engine by the belt, not directly as we know.

A stock off-the-shelf 1 litre performs like a 2 litre and gives a 47% improvement in MPG. The electric turbo is the key to get more accelerating power from the small engine, only cutting in on acceleration. The supercaps provide the surge of electricity needed when say acceleration is needed or to the starter/alternator.

A large car running at 70mph on an Mway only needs about 20hp. This setup can turn off the electric turbo and the car will be propelled by the 1 litre engine nicely, instead of most of the 2 to 3 litres going waste. When more power is needed the electric boost turbo comes in.

Anhui Jianghuai Automobile in China are taking it up. They make around half a million cars a year. So a fair sized outfit. So, an engine half the displacement, with the same performance and a 47% improvement in fuel consumption. Can't be bad at all.

Jay Leno....
https://www.youtube.com/watch?v=X9vZLYMoTCQ

Edited by RayTay on Sunday 8th January 15:46

[RayTay]

dme123 said:

You're also only getting one power stroke per crank revolution, alongside the out of balance forces of a 3 cylinder engine so it'll be as rough as a badgers arse unless you use two of them in an I6 and V6. Even then you'll only have power strokes 180 degrees apart, and you've left the economy minded marketplace behind.

The power strokes can be better spaced around crank rotation using a V6, with the two power cylinders on one bank using the expansion cylinder on the other bank. A narrow V6 all on one block and cylinder head like VW did may be the ideal setup.

Ilmor did make and test the engine which gave excellent results. They say it can also have a turbo to claw back more wasted energy. They were on about the range-extender market, running at a constant speed. The expansion cylinder is passive and maintenance free and 'should' warm up the engine quicker - an advantage. Fast warm up is gaining attention. GM have cooling water in the exhaust manifold for a quick warm up in one hybrid engine. When up to temp the exhaust water coils are by-passed by the exhaust gasses.

I just posted about the Ricardo HyBoost using two turbos - one mechanical and one electrical. I seems to work. I would like to see the results of the two turbo Ricardo HyBoost system applied to the 5-stroke. That would be interesting.

Edited by RayTay on Monday 21st November 17:30

[RayTay]

dme123 said:

You're also only getting one power stroke per crank revolution,

One power stroke per rev yes, but it is assisted simultaneously by the expansion cylinder.

Edited by RayTay on Monday 21st November 10:38

[RayTay]

PetrolJosh said:

Electric power is the way the world seems to be going, whether that is good or bad remains to be seen, but there has been big progress in electric cars in the past few years at least.

A free-piston range-extender generator, developed at Newcastle university:
https://www.youtube.com/watch?v=u4b0_6byuFU

Using HCCI ignition:
http://www.ncl.ac.uk/business/knowledge-exchange/t...

Things are moving on. The video says in 10 years time 8 million hybrids will be made. I think that is an underestimate, when taking into account buses. Once they are affordable they will really take off. Also many cities may ban cars other than at least a hybrid or 100% electric.

Edited by RayTay on Tuesday 22 November 19:35

[RayTay]

RayTay said:

A free-piston range-extender generator, developed at Newcastle university:
https://www.youtube.com/watch?v=u4b0_6byuFU

Quite amazing the R&D on free-piston linear generators that is going on:
https://en.wikipedia.org/wiki/Free-piston_linear_g...

1. Libertine LPE, UK.
2. West Virginia University (WVU), USA.
3. Chalmers University of Technology, Sweden.
4. Electric Generator, Pontus Ostenber - 1943
5. Free Piston Engine, Van Blarigan, Sandia National Laboratory, USA - Since 1995
6. Aquarius Engines, Israel.
7. Free-Piston Engine Project, Newcastle University, UK. - Since 1999
8. Shanghai Jiaotong University, China.
9. Free-Piston Linear Generator, German Aerospace Center (DLR) - since 2002
10. Free Piston Power Pack (FP3), Pempek Systems - 2003
11. Free Piston Energy Converter, KTH Electrical Engineering - 2006
12. Linear Combustion Engine, Czech technical university - 2004
13. Internal Combustion Linear Generator Integrated Power System, Xu Nanjing, China - 2010
14. Micromer ag (Switzerland) - 2012
15. Free-piston engine linear generator, Toyota - 2014

Edited by RayTay on Saturday 26th November 17:08