Automotive: why 2 stroke engines were not used, even in competition?

[Christophe]

Little thought that I made myself yesterday: why the engines 2 time (conventional) were not used in automobile (except some exceptions like Trabant 601: https://fr.wikipedia.org/wiki/Trabant_601 ... from the east block).

Obviously everyone will think about pollution and consumption, much higher than on 4 time. As well as a lower reliability. So we understand why the 2 time is not suitable for everyday use.

But why haven't they been used in motor racing? Formula 1, Rally and others ... where pollution, consumption and reliability are less "important" than in urban use? The advantage of 2-stroke is obviously its weight / power ratio and a lower manufacturing price.

The 2 time engines were used in motorcycle racing until 2002. Yet the tank of a motorcycle is less important than that of a car (and the power of 2 motorcycle time exceeded the 200 CV ... so enough for a car).

Can be a question of torque curve? More pointed and more appropriate to lighter masses? Or simply a story of ... FIA regulations?

[chatelot16]

there was 2 car time ... she disappeared because she was not the best

Citroen has been studying 2 time solutions to make CX

the 2 temps have been favored in motorcycle competition by regulations limiting the engine capacity ... so has limited displacement is the 2 time is the most powerful

the same for the 50cm3: the limitation of displacement is absurd and favors the most polluting engine

in truck and agricultural there was 2 diesel time quite efficient: see the detroit diesel engine that make a noise of formula one ... it was mounted in coach berliet cruisair

[Christophe]

Oh yes, I was only thinking of "conventional" 2-stroke, therefore petrol ... and for the automobile, therefore "reduced" displacement.

On consumption and pollution, there was 2 injection time that worked well in the 2000 years but I do not know if they were mass produced finally ...

2 slow diesel times have the best thermodynamic efficiencies in the world (54% on top Sulzer)

[chatelot16]

2 carburetor single time is a waste of gas ... there is always some of the gasoline coming out the exhaust

the 2 gasoline time injection avoids the loss of gasoline since it injects when the lights are closed, but it takes the inconvenient of the diesel: limited speed of rotation and emission of fine particles

same story for the 4 time: some fuel injection engine make fine particle like diesel without having the same advantage of good performance as a real diesel

there is still something to invent in motor but I think that the solution is an optimization of 4 time ... first part of cooled compression, with turbine or piston optimized for low pressure ... prolonged relaxation in other piston

thanks to the cooled compression, the prolonged relaxation makes it possible to make an escape at ambient temperature: maximum yield!

Another advantage of the cold exhaust: condensation! easier recovery of fine particles

[Christophe]

Another advantage of the cold exhaust: condensation! easier recovery of fine particles

And water for reinjection into the cycle

[chevesne51]

True, they were rare, but I remember still, the inimitable sound of DKW in rallies.

Do not forget, though without success:
http://www.les24heures.fr/1963/201-1963-voitures/503-1963-56-cd-manzel

[Christophe]

Thank you for the info, the 2 time has existed ... briefly in competition ... but with the case (cqfd so?).

Here is a video of a modern DKW, a pity that the soundtrack has been removed by Youtube:

https://www.youtube.com/watch?v=xY_CO3SSbp4

[Christophe]

Ah here is a sound track:

https://www.youtube.com/watch?v=IbSM-h_nmi8

[Flytox]

A good summary of the chaotic history of the 2 stroke and a conclusion not "expected" in the concert of disinformation of shit.

http://www.motoservices.com/panne/moteur_2_temps.htm

[Flytox]

For Honda, the main actor of the disappearance of 2 time in great price, they saw their cutie .... with a two-time valve.

http://www.gp-inside.com/12013/24-juil- ... au-2-temps

Motor champion of unbalanced oscillating movements? Sure that this utility should not be able to run very fast!