MCE-5, the VCR-i engine mounted in a Peugeot 407

[Christophe]

I think Bucheron has already answered this remark, right?

In addition, nothing prevents, in theory, from applying this to smaller engines and obtaining an inconceivable downsizing with "classic" engines: 400 cm3 for 50 hp ...

[Remundo]

One of the errors of MCE5, it is to want to act on the main piston to modify the compression ratio ... However it is much more elegant and especially effective to add a small additional piston above the combustion chamber . This allows the decoupling of the kinematics of the engine with the adjustment of the compression ratio. This is far from negligible ...

Playing on the volume of the combustion chamber through the cylinder head has already been done on engines in which this body is much simpler (2T) in the 90s and it never really worked ...
Given the complexity of a cylinder head and given the shape constraints to which the combustion chamber must comply, I would like you to explain your principle a little more.more elegant and more efficient"next to which the engineers of MCE-5, these ignoramuses, passed?

I never said they are ignoramuses. The MCE5 concept was frozen over 10 years ago at a time when hybridization and power reduction were irrelevant. Since then, the engine issue has evolved well. And some have just pointed out that the proposed engine is too powerful, I say above all that it is too big and heavy.

The future of the engine is to be smaller and smaller and to be integrated into hybrid architecture: be careful, small does not mean starvation: 70 to 100 hp should always be kept available for road vehicles.

Good to return to MCE5, a team of twenty engineers working on it for 10 or 15 years (I don't remember the exact date ...): they got so caught up in the project that reversing is impossible. It was the headlong rush, and Peugeot never showed much interest, the other manufacturers even less.

Furthermore, I do not understand what it changes to vary the volume of the combustion chamber from the top (cylinder head) or from the bottom (piston position)?

Christophe gave part of the answer: mechanically, it is much easier to adjust an organ that does not transmit power (like that, the kinematic chain is simple and preserved) than to adjust an organ which transmits it.

For the anecdote, MCE5 mainly has a Swiss company in its share capital, one of the main financiers of which is a family of hypermarket managers ...

@+

[Christophe]

Christophe gave part of the answer: mechanically, it is much easier to adjust an organ that does not transmit power (like that, the kinematic chain is simple and preserved) than to adjust an organ which transmits it.

Yes simpler but (more) effective not on?
Bucheron also gave an answer: acting on the shape of the cylinder head (via a variable annex chamber a bit like a ricardo chamber on "old" diesel) is to screw up all the optimization of combustion ...

Playing on the volume of the combustion chamber through the cylinder head has already been done on engines in which this body is much simpler (2T) in the 90s and it never really worked ...

On the other hand it would have been possible to make make the cylinder head "floating" rather than the piston .... this is what is done on experimental engines with variable compression ratio (when stationary).

I think there is at least one VERY good reason for not having chosen the floating breech version for the MCE: starting with thesealing no?

[Flytox]

I think Bucheron has already answered this remark, right?

In addition, nothing prevents, in theory, from applying this to smaller engines and obtaining an inconceivable downsizing with "classic" engines: 400 cm3 for 50 hp ...

A 'traditional' motor cannot have a 'too' small cubic capacity and good efficiency. I had found an article (chai plus or? ) on this subject saying that below about 300 cm3 per cylinder the thermal losses by the walls were 'too' important and that the efficiency fell rapidly. Being a 4-stroke, to have a minimum of flexibility we need 4 cylinders, this gives us a "minimum" displacement of 1200 cm3 approximately.

There may be a good compromise with 3 cylinders and 900cm3. In addition, this would meet the judicious criteria of space and lightness of Remundo.

The future of the internal combustion engine is to be smaller and smaller and to be integrated into thermal architecture: be careful, small does not mean starvation: you will always have to keep 70 to 100 hp available for road vehicles .

For the standard passenger vehicle, this 70-100CV power is comfort and pleasure OK. For the need to be able to reach 130 km / authorized limit in France, there are enough with 50 CV!

If we optimize for the need instead of optimizing for the pleasure, sure that we will sell fewer cars, but we can maybe aim and achieve a consumption that tends towards 2 or 2.5 liters / 100 Km.
A+

[Flytox]

Bonjour Christophe

I think there is at least one VERY good reason for not having chosen the floating breech version for the MCE: starting with thesealing no?

So that the distribution can operate with height changes, without making an incredible machinery, this seems to condemn to make orders of electromagnetic or electropneumatic valves.
A+

[RIAZ]

The future of the heat engine is to be smaller and smaller and to be integrated into thermal architecture: beware, small does not mean starvation: always keep 70 to 100 Ch available for road vehicles.

But why then?
For what mass?
For what need?

Your fork cut in 2 will be enough.

[Woodcutter]

[...] Being about a 4 time, to have a minimum of flexibility it is necessary 4 cylinders, that gives us a displacement "minimum" of 1200 cm3 approximately. [...]

It's not sure ... a twin could still be suitable, but with large balancing shafts.

Fiat is currently working on a supercharged CNG twin.

[Christophe]

Flytox, I think that your assertion may have been justified at one time but that it is much less currently ... with the progress of the optimization of combustion.

Just a small remark on the power density which seems "miraculous" to you: you would not have forgotten ...motorcycle engines?

Any 600 SERIES sports car currently in the 120 hp (see much more if a little prepared) ...i.e. 200 hp / L...It's standard, it's not a prototype, so reliability is by appointment!

http://www.moto-station.com/article3918 ... route.html

Information

Engine: 4 cylinders in line, 4 stroke, 599 cm3, compression ratio 12.8: 1, bore 67 mm x stroke 42,5 mm, water cooled, 2 ACT and 4 valves / cyl. (titanium), forced air intake, 8-point electronic injection, 6 speeds, multi-disc clutch in oil bath, chain transmission
French version: power 106 hp. (78 kW) at 11 rpm, torque 500 daN.m at 6,1 rpm
Free version (= not restricted): horsepower 125 hp. (92 kW) at 13 rpm, torque 500 daN.m at 7,8 rpm

And if the pilot does not drive like an idiot (by pulling in cold) a sportswoman can exceed the 100 km ... but generally it is HS before because of the prank trees ...

[Woodcutter]

[...] And some have just pointed out that the proposed engine is too powerful, I especially say that it is too big and heavy.

I will, once again, repeat my (precise) question: do you think that this engine (whole, that is to say with all its accessories) is really much bigger and heavier than a displacement and identical technology (excluding VCR)?

Have you ever seen a VAG TSI?

[...] The future of the heat engine, it is to be increasingly small and to be integrated into thermal architecture: attention, small does not mean starving: it will always be necessary to keep 70 to 100 Ch provision for road vehicles.

Why could not what was done on a 1.5 l be done on an engine half the displacement?

[...] Good to return to MCE5, a team of about twenty engineer bump on it for 10 or 15 years (I don't remember the exact date ...): they got so caught up in the project that the reverse is impossible. It was the headlong rush, and Peugeot never showed much interest, the other manufacturers even less.

Regarding the interest of manufacturers, it is not really what emerges from what they say, but I agree that we can not be judge and jury. Where do you get your info from?

By the way, what exactly are "confined" and "forward flight"? To the technology developed or to the implementation on an engine "overweight"?

[...] on the mechanical level, it is much simpler to adjust an organ which does not transmit power (like that, the kinematic chain is simple and preserved) than to adjust an organ which transmits it.

Well ... maybe if they went in that direction, it was because it was much easier to adjust a "tight and simple-shaped" organ (even if it transmits power), than another very complex organ, with a tortured and almost frozen form (but which does not transmit power)? Finally, I ask myself the question ...

[Woodcutter]

[...]
Any 600 SERIES sports car currently in the 120 hp (see much more if a little prepared) ...i.e. 200 hp / L...It's standard, it's not a prototype, so reliability is by appointment!
[...]
And if the pilot does not drive like an idiot (by pulling in cold) a sportswoman can exceed the 100 km ... but generally it is HS before because of the prank trees ...

Regarding motorcycle engines, I would already agree more with Remundo on the maintenance to be made ...
I'm a bit out of the motorcycle world, but when I had my LC4, a mono that turned at 90 hp / l, maintenance was still really important: regular oil change, very good oil, crankshaft bearings and camshaft to change regularly, etc ...

The main problem, in my opinion, of powerful atmospheric engines lies in the stratospheric rotation regimes. Not sure if this type of feature is compatible with a long service life ...

This is also where one of the advantages of the MCE-5 resides: really low rotation speeds, a bit like a diesel ...