<< Our discussion of intake air velocity made me think of
> >an old British engine called the Cross rotary valve engine.
> >As I recall. Here is a sketch from memory I made.
> >When I was a kid I was fascinated by this engine.
> >
> >The large bearing was necessary as the force on the rotary valve
> >was considerably during the combustion cycle.
> >
> >Note the huge intake and exhaust ports unencumbered by any silly
> >poppet valves. This gave much more port area than a sleeve valve
> >engine.
> >
> >The engine ran well and probably was the most successful of a long
> >list of rotary valve piston engines including one designed by Felix
Wankel.
> >
> >Problems are cooling the valve, sealing and the opening and closing
> >times as the valve rotated at 1/2 crank speed just like a cam shaft.
> >Also deflection of the valve might cause rubbing on the cylinder head.
> >The spark plug rotated along with the valve. Bulk in the cylinder
> >head was also a problem.
> >
> >I think perhaps with modern materials such titanium for the valve
> >this engine may have a few possibilities. If the rotary valve is
slammed
> >around electronically to index the ports as required the timing
problem
> >could be over come. In fact the opening and closing times of both
> >intake and exhaust ports could be closely controlled by a computer.
> >
> >I am not naive enough to think this will ever be tried but be wary
> >of some shyster selling stock to develop this engine. I would say
> >its chances of succeeding are at least 1000 to one and maybe
> >as much as one million to one :-)
> >
> >Paul Lamar
> Interesting. If you flowed oil behind the valve with suitable
> seals (not sure HOW) it would cool and support it. Did this
> ever make production?
>
> Bill Freeman
> Long EZ builder & pilot
> BSME, MSME
> EAA Technical Counselor
There is a model airplane engine available now that has a similar
layout. The
whole cylinder rotates at half crank speed. Very interesting.
Lynn E Hanover
Yes I have some stuff on that. Here is a jpg. The neat thing about
this layout is the prop shaft runs at half speed to that of the
crank. The draw back is the valve opens and closes too slowly
there by limiting the breathing. With my version the rotary
valve is slammed around with high angular acceleration opening
and closing the the valve rapidly improving the breathing
and optimizing the timing for speed or torque. Kind of like a
cam shaft but without the drawbacks. In almost all Cross type engines
the rotary valve has been geared somehow to run at half crank speed
so far. To my knowledge.
Paul Lamar
Paul,
Sounds neat, but you can do some things on model scale that won't
work on real scale.
Why didn't the sleeve valves used in the Bristol Centaurus (2500 hp
WW2 fighter engine) catch on? I've always admired the Sea Fury
and that engine, but even though it was apparently very successful,
the technology didn't move down into cars. Seems a shame, but
perhaps there were problems. Any insight?
Bill Freeman
Actually the technology came from cars. I believe the Knight car engine
was the basis for the Bristol sleeve valve.
Paul Lamar
OK, then tell us about the Knight car engine, which I never heard of.
I assume British, pre-war. Sports car or touring? How are the sleeves
actuated? I have read something like "operated by complex linkages"
but that's no help. Did the Knight have problems. Seems like they
should have been great in racing, but they didn't leave any mark that
I have heard of.
Bill Freeman
The early Knight engine had two sleeves one inside the other.
The Knight engine was used in the American Willys-Knight,
the Belgian Minerva and the English Daimler cars.
Problems were oil consumption and starting.
What Bristol settled on was the one sleeve version called the
Burt McCollum type used in the Scottish Argyll car.
Posted by Douglas Woodard on September 19, 2000, dwoodard_ad_becon_dot_org
Sleeve valves do not use a rotating disk but a reciprocating and rotating cylinder. Wankel invented a disk valve early in his career which was not widely used,
and the Aspin and Cross rotating valves may be of interest.
The Knight double sleeve valve was used by several car makers early in the 20th century, mostly by Daimler in Britain. It went out of use because it was hard to
lubricate and made for a very smoky (although smooth and quiet) engine.
The Burt-McCollum (spelling?) single sleeve valve was successful (after much development) in British aircraft engines around WWII, notably the Bristol
aircooled radials, the Perseus, the Hercules, and the Centaurus, along with the sparsely produced Aquila and Taurus and the experimental Orion. The Napier
Sabre (liquid cooled flat H24) was used in in some British production fighters (Hawker Typhoon and Tempest) and some experimental aircraft. Rolls-Royce
finally switched to the sleeve valve for the experimental Exe and Crecy and its last production design the second Eagle (liquid cooled flat H24 of 3500 hp)
which was produced in small quantities (I think about fifty) for the first version of the Westland Wyvern naval strike aircraft.
The British Air Ministry contracted for research on the single sleeve valve by Ricardo Engineering and Bristol Aero-Egines in the 1920's; the most attractive
feature at the time seemd to be the possibility it offered of working at higher compression ratios and thus giving more power and economy. After the
development of the sodium-cooled poppet exhaust valve, the sleeve valve was not so attractive but the British thought it still had advantages and persevered.
Pratt and Whitney in the US experimented with the sleeve valve but did not put it into production, which they may eventually have come to regret when they
got deeply into the R-4360 program.
Some postwar production aircraft which used Bristol sleeve-valve engines were the Bristol 170 Freighter, the Handley-Page Hermes, the Blackburn Beverley,
and the Nord Noratlas.
I think there were a few limited-production cars (Bristol and others) up to about 1950 which used the single sleeve valve . There may be a sleeve valve research
engine still in production in very small quantities, possibly on a special order basis.
You will find information on the sleeve valve in several books, notably:
Some Unusual Engines, by L. J. K. Setright (U.K., 1970s?)
Memories and Machines, by Sir Harry Ricardo (Autobiography). London: Constable, 1968.
The High-Speed Internal Combustion Engine, by Sir Harry Ricardo, several editions (5th edition by Ricardo and Hempson, Edinburgh (?): Blackie (?), 1957).
The Ricardo Story: the Autobiography of sir Harry Ricardo, Pioneer of Engine Research.
Published by the Society of Automotive Engineers, 1992.
Engines and Enterprises, the Life Work of Sir Harry Ricardo by John Reynolds
Alan Sutton Publishing, 1999.
By Jupiter! (Life of Sir Roy Fedden of Bristol Aero-engines)by Bill Gunston (U.K., 1970's?)
Fedden by Bill Gunston (U.K., 1990's?)
Sir Roy Fedden published two articles on the development of Bristol sleeve-valve engines in the Journal of the Royal Aeronautical Society. I think one was in
1948 and the later one might have been about 1956.
Douglas Woodard St. Catharines, Ontario, Canada
I have the Gunston book up at the hangar I think. Can't find it around here.
Interesting and highly detailed book on the developments of the sleeve
Bristol engines.
See also the History of Aircraft Piston Engines by Herschel Smith.
Paul Lamar
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