A clean 2 stroke engine? Alpha Otto

[jo1010]

This may see some future benefits for two strokes. Maybe maybe.....

 

[Morris]

Another one?

 

[jo1010]

Another one?

Hmmm, I know... But as consumer experience of whole lifecycle costs grows with battery powered machines, I wonder which way manufacturers will go....

 

[Dozzer]

Hmmm, I know... But as consumer experience of whole lifecycle costs grows with battery powered machines, I wonder which way manufacturers will go....

Toyota. MB and VAG have all recently increased their investment ICE on the quite, was asked about 12 months ago if Ford reopened the engine design department at Dagenham would i go back.
Many manufacturers are keeping their options open.

 

[Morrisman]

This may see some future benefits for two strokes. Maybe maybe.....

I heard a story that one of the owners or workers at CCM had left a couple of years ago to focus on some new clean 2 stroke bike engine project. There was talk of 70hp from a 250, which seems well within the scope of the one in the video.

 

[Morris]

It uses yet another example of that technological dead end the rotary valve.
It's all very well saying that it doesn't see combustion pressure but it still sees heat cycling which is part of the problem with them.

 

[jo1010]

....but it still sees heat cycling which is part of the problem with them.

I only know about heat cycling after rebuilds - are you saying that rotary valves can never be heat cycled properly and have a short life thereafter?

 

[Morris]

@jo1010 rotary valves have to run very tight tolerances so any distortion caused by heat leads to problems. It also gives the bearings a hard time. The history of rotary valve engines is mostly examples of such problems.
There have been some semi successful examples but they never live up to the potential or live very long.
Maybe this one will be different.

 

[Morrisman]

Hopefully some modern technology and material can improve over past attempts. One thing with this particular design is the rotary valve doesn’t ‘see’ the whole combustion cycle, just the last 1/4 or so.

 

[hotponyshoes]

Could you make one that was pre-heated to avoid the issues with thermal expansion?

Fit it to a hybrid so you had a good source of electrical power for the pre-heating?

The main downside would be that you would have to wait for it to warm up before you could start it but if it was controlled by a phone app that also updated your facebook status to say you were going out then people would love it..

 

[Morris]

The Holden- Dunstan "grey motor" is a well known rotary valve engine built in Australia. Approximately 30 units were built and they were powerful and revved well. But that was it, 30. They had problems with cooling, lubrication and sealing and that was one of the better ones.
There's plenty of other examples but they all suffered with similar issues. Maybe the unique way that the valve is used in this engine will be the breakthrough that saves the idea.

 

[jo1010]

Hmmm, clever ideas but having forced induction and a semi-dry sump might limit it's application for machines at the cheaper end of the market....