engine and drivetrain Rotary Valve M10

[Rocan]

Aside from my love for 02's (and all cars), I have a love for engineering and machining. Once in a while, I find a video that really interests me as it combines all aspects of my favorite hobbies into one. The following is one of those videos.

 

 

Now, at about 3:20 into the video, right near the end, I spotted something extremely interesting. 

A "1985 BMW with Rotary Valves"

 

Seeing as how it is a 4 cylinder, I could only imagine it is an m10. 

 

 

I'm curious what one of these would go for... surely much more rare than even a schnitzer twin cam setup. 

 

 

And I'll just leave this here. 

 

[aholderith]

i've never heard of these before. very cool.

[danco_]

Where do I send this blank check?

[aholderith]

Are there any advantages to this system besides "simplicity"? Why aren't these used today?

[KFunk]

How does the 'valve' seal against the combustion chamber?

[TobyB]

Personally, I miss the old sleeve- valves...

 

hee

 

t

[Mike Self]

Back in 1912 a car called a Speedwell used an engine with rotary valves, designed by an engineer named Mead--right here in Dayton.  The Mead engine had rotary valves that were ports cut in a rotating steel shaft (think of a DOHC engine), with the sealing provided by small diameter piston ring-type seals on each side of the valve chamber.  The design was supposed to cure the problem with valve burning that was common to engines then due to the poor metalurgy of the day.  In theory the rotary valves were a great idea; in practice, not so much.  They never could get the rings to seal tightly enough to work properly, even with the typical 4.5:1 compression ratio that engines had back then. 

 

The result was that Speedwell had to recall nearly all their 1912 production cars and replace the engines with ones that had conventional valves.  Then in March 1913 the Great Dayton Flood inundated the entire factory and damaged the entire winter's car production.  Speedwell folded that year.  The factory building still stands.

 

Wonder if the Aussie design has solved the shaft seal problems that killed the Mead Rotary Valve engine...

 

 

cheers

mike