Two stroke valves in a Four stroke engine .

[Yohan]

A Swedish engineer has designed out the normal four stroke valves with springs etc and inserted the well tried 2 stroke types instead. Not to convert an engine from one to the other but strange how long the idea has been to make the jump . I think reed valves is the type he uses .
The (John ) Elwood 1300cc and Elwood 500cc are the 2 machines mentioned . The designer is a one off racer /engineer . I wonder if Alan would be interested . The intake gases are compressed and held ready for the next stroke. Also used is a cross head rotary valve . If anyone knows about that please help us with it . The big one produces the thick end of 150 horses at about 7,000 revs . An Australian interviewer chats with John about his bike and the prototype is started up at the end . It has no gearbox!!! The single piston is huge . The cylinder head is a thing of beauty .

 

[Andrew Shadow]

I don't think that this is anything new. I remember reading about this years ago. I can only assume that it didn't provide a sufficient enough benefit to entice manufacturers to switch engine design at the time. Maybe this Swede has now significantly improved the design making it more viable now.

 

[Sadlsor]

Anyone have a number for Kevin Cameron?

 

[dduelin]

The idea of using rotary valves in a four stoke engine is over a 100 years old. I didn't know it was this old until the link below popped up because I was searching for an engine design from the 1980's that utilized two cylindrical rotary valves on top of the cylinders in place of conventional dual overhead cams set above the cylinders. I couldn't find a reference to the one I was thinking of.

1911 Reynolds Rotary Valve 4-Cyl. Engine

Robert A. Reynolds started his design and developed his rotary valve engine around 1903. He continued experimenting and perfecting this engine for eight or nine years before introducing it to the public. A 4-cylinder, rotary valve type engine was produced

www.museumofamericanspeed.com

 

[Yohan]

Yes the history comes into the interview .It was connected with a military design . No attempts to cover up anything .For a Swedish guy he sounds like he came from Bradford .

 

[Yohan]

I need to watch the video again to work out how that cylinder head valve turns inside the engine . The car engine with four rotating gearwheels over four cylinders must have added plenty of weight . Because the bike is still a 4 stroke I was surprised at the blue smoke coming out of it . You have to admire Elwood`s tenacity when he is not really a trained engineer . Not knowing how to weld aluminium must be drawback when engines are just made of the stuff . I would like to see him convert a large Panther engine to see if the starting routine could be made even more complicated .

 

[bdalameda]

There have been all kinds of weird valve type experimented with. Rotary valves, sleeve valves, reed valves. Also GM had prototype solenoid electronically controlled valves that timing, opening curves could have infinite adjustments. One of the oddest engines had an adjustable stroke that could be changed during operation. Vespa had an engine where the actual crankshaft was the rotary valve in the case. Don't forget about Desmodronic valve operation.

 

[Craig246]

I remember reading about a "sleeve" valve engine. I think Kevin Cameron wrote it.

 

[Ashley]

Pneumatic ones in Formula One in the 80s

Pneumatic Valve Actuation

www.formula1-dictionary.net