This is an engine which can switch between 2 and 4 strokes. Can anyone explain how this engine works?

You need to work the google machine harder next time,

Link

Brian,

Thanks Mr. BrianGar for the link. I had a look at that before and once again when you shared it. The file gives information about the results they have achieved and the working of the 2 modes. But I had problems in understanding the 2 modes that have been shown( the pictures aren't very clear ) and if possible could you please explain me in simple the 2 modes of operation and what happens during the switching process.

Thanks once again.

061 etc. -
I have taken a fair bit of interest in this 2/4 engine also.
I think this is (or was) the intended mechanical switching valve gear:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PT...

I think the original running Ricardo engine used electro-hydraulic valve gear - the mechanical valve gear was intended for later versions.
There are also other ways the mechanical switching could be done.
I suspect the switching process is meant to be so fast that it is not important what happens during this period - the engine is certainly going to be a little confused.

Even though the engine is an interesting idea I don't know just how useful it would be.

The switching process in action...

http://www.youtube.com/watch?v=6lTwsy1oOR0

- Steve

Quote:

"I suspect the switching process is meant to be so fast that it is not important what happens during this period - the engine is certainly going to be a little confused."

That is an understatement! I suspect the crankshaft design must be pretty beefy.

that was exactly what I was also thinking about.... balancing the crankshaft for the forces and moments would have been quite a task... wondered how that was done....

06etc. - I really don't think whether an engine is two or four stroke comes into the balancing of the rotating and reciprocating bits of an engine.

Quote (BigClive)

Even though the engine is an interesting idea I don't know just how useful it would be.

Isn't it really just a different approach to obtaining variable displacement?


Norm

@NormPeterson:

No. Downsizing has its challenges. This is one possible solution - to fill the missing lump of torque at lower engine speeds you get with a smaller engine. The basic idea is to use what metal you have to the best effect. There are other solutions of course.

Carrying half an unused engine around (cylinder deactivation) doesn't seem the best policy to me. Unless of course your brand image demands V8, even though only I4 power is required for most of the time. What happens to the bores of the motored bank anyway? Do they get polished?

- Steve

We're saying the same thing, just from a different perspective.


Norm

Norm,

That was my initial thoughts too, albeit in a different guise.

Brian.