Second piston controlled valving

[761TJ]

I saw a video of an engine on a motorcycle that used a piston in the cylinder head as the valving. Excellent torque.

Anyone know what I am refering to?

Thanks,

Ed

 

[MikeHalloran]

I remember reading about a bike engine with a piston-sized rotating drum valve in the head. ... forty years ago.

No progress has come to my attention since then.



Mike Halloran
Pembroke Pines, FL, USA

 

[tbuelna]

761TJ,

There was a poster here named malbeare (?) that was working on just that type of engine. I believe he is an Aussie. I've exchanged a few emails with him and he seems to be a very personable fellow. I'm sure he would be happy to talk to you about his "six-stroke" engine if you can locate him.

http://en.wikipedia.org/wiki/Beare_Head

Good luck.
Terry

 

[761TJ]

Thanks Terry that is what I am looking for.

 

[patprimmer]

From my memories, that engine had extremely high power at extremely high rpm but reliability problems were also extreme, especially the seals on the valve system.

It was essentially a pipe bigger than the bore that was across the top of the bore. It had a plug in the middle of the pipe that separated the inlet and exhaust ends. it was at about a 45 deg angle to the axis and may have been shaped to streamline flow into the bore.

Each side of the divider had a hole the size of the bore and as the pipe rotated in the head, the intake and the exhaust side holes were exposed to the bore in sequence with the crank.

The seals between the pipe and the head were a problem as I recal from reports at the time.

Regards
Pat
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[db600]

I think you may be referring to the Aspin and Cross designs both of which have been tested extensively by various manufacturers, prewar,Austin converted some 4 and 6 cylinder engines to work with these types of rotary valve but the benefits were to costly. From an engineering standpoint though these designs offered high MEP,exceptional knock resistance, good specific power output coupled with good fuel consumption. All of course at a price and as we all know many good ideas have died on the accountants altar but who knows these might come into use driven by current pollution concerns.

 

[CH5OH]

I believe i saw that movie to, a converted cylinder head of a ducati....
the drive of sliding valves was done, if I remember correctly by modifying the ratio of the camshaft from 1/2 to 1/1