Sealing in Ricardo's sleeve valve engines
Sealing in Ricardo's sleeve valve engines
(OP)
These engines keep bothering me. :-)
Was the lube oil consumption outrageous in modern terms? Would any modern fluids or materials or designs help there, if you were to implement something like that today?
How was the port sealing (for gasses, as well as and oil) done? I don't have access to details, what's online doesn't tell much.
Was it a good design, if you compare it to today's poppet valve engines (with multiple valves and adjustable valve timings and whatnot)? I mean, did the sleeve valve offer any inherent benefits, and how much of a drawback is the radial (side) rather than axial (head) flow? If the engine has charging?
Was the lube oil consumption outrageous in modern terms? Would any modern fluids or materials or designs help there, if you were to implement something like that today?
How was the port sealing (for gasses, as well as and oil) done? I don't have access to details, what's online doesn't tell much.
Was it a good design, if you compare it to today's poppet valve engines (with multiple valves and adjustable valve timings and whatnot)? I mean, did the sleeve valve offer any inherent benefits, and how much of a drawback is the radial (side) rather than axial (head) flow? If the engine has charging?





RE: Sealing in Ricardo's sleeve valve engines
Oilconsumption in modern times sure was not good, but in those days they were no worse then poppet valve designs that needed decoking quite often whereas the sleeve engine could attain a much higher mileage before needing service.
RE: Sealing in Ricardo's sleeve valve engines
Many other interesting topics at this site as well.
The sleeve valve breathing characteristics are actually quite good, due to ability to change the valve area between zero and max quite quickly. Other than its late start (at least in the cutting edge aero realm) relative to the poppet valve, drawbacks were higher thermal resistance between the inner liner and the heat sink (i.e. cooling fins or water jacket), and as in a piston ported 2-stroke, issues related to the piston rings running across the ports every stroke.
"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
RE: Sealing in Ricardo's sleeve valve engines
RE: Sealing in Ricardo's sleeve valve engines
RE: Sealing in Ricardo's sleeve valve engines
jack vines
RE: Sealing in Ricardo's sleeve valve engines
Can they compete against poppet valve engines in the automotive, small engine or light aviation sectors? No.
je suis charlie
RE: Sealing in Ricardo's sleeve valve engines
https://www.youtube.com/watch?v=qrkqL3sBogA
The main reason for not using sleeve valve is number one they cost a lot more to manufacture. Number two is lubrication is difficult. And I agree it is a much better system and more durable. In this day of disposable engines, cars etc. there is no need for durability.
RE: Sealing in Ricardo's sleeve valve engines
Going off on a tangent now, I too detest the day of disposable engines. I've seen a referral of a study on the production energy costs of a small modern car (with its engine). Made it look like it's better to keep the old stuff running and not fill the landfills to the brim with this not particularly organic stuff.
But I didn't quite get a detailed answer on the sealing question. I'm sure (from some sources) that oil consumption was higher, but what was mechanically done to seal it? (And port gases.) Some kind of metal spring arrangement, something like piston rings, or just pressure differential sealing?
RE: Sealing in Ricardo's sleeve valve engines
I still can't help thinking of a sleeve valve system in the context of a modern charged direct-injected diesel. In a naive version, no need for intake port swirl if the piston shaping handles it. More boost if there's no head and head gasket. Better combustion temperature control when needed if the head is just flat and dumb.
Obviously it isn't so simple, but it's a useful jumping (off) point for further studies on the highly empirical art of engineering.
(Bear with me. I'll have a high read:write ratio...)
RE: Sealing in Ricardo's sleeve valve engines
4-stroke sleeve valve engines still have heads and head gaskets. The head "gaskets" are just piston rings. The cylinder heads of conventional 4-stroke poppet valve DI diesel engines are also flat, and the combustion chamber is part of the piston crown. One of the largest sources of friction loss in a high-pressure diesel engine are the piston rings. So doubling the number of piston rings required in a 4-stroke sleeve valve engine would not be good for efficiency. One significant limit with high-pressure diesel engines is heat transfer from the piston rings across the cylinder wall. The heat transfer situation with the added sleeve valve thickness is far worse. Lastly, how would a thin wall, large diameter sleeve valve handle combustion pressures of 2500psi or more?
RE: Sealing in Ricardo's sleeve valve engines
Sorry, but I just don't understand the above. Those of us in the rebuilding industry now see engines running 3X the miles/km and being in better shape at teardown. With a few exceptions, today's engines (and cars) are built to a much higher standard in and will last many times longer/farther than anything built back in the day.
Yes, I was there then too and rebuild obsolete engines today. Carburetors, distributors and leaded gas are the devil's devices and killed engines long before their natural death.
Today, we can take a '70s big block Ford or GM V8, rebuild with today's QC and parts, add EFI/computer control and it will run at full torque 3X as many hours as it did in its first life.
jack vines
RE: Sealing in Ricardo's sleeve valve engines
RE: Sealing in Ricardo's sleeve valve engines
RE: Sealing in Ricardo's sleeve valve engines
- I think one extra ring is typical.
- The extra ring has far less travel and rubbing speed, therefore less friction.
- I believe heat transfer is not an issue. The sleeve "grows" and the clearance decreases until delta T, heat flux and thermal resistance match up.
- The thin wall sleeve is also supported by the cylinder it runs in (via the oil film - even the full 2,500 psi is low for an oil film)
je suis charlie
RE: Sealing in Ricardo's sleeve valve engines
The junk head rings had far worse lube oil conditions than the piston rings.
The junk head rings were subjected to the same combustion pressure forces as the piston rings. The sliding frictions they produced on the sleeve valve were continuous during operation since the sleeve valve never stopped moving. Poppet valves on the other hand don't produce friction losses when they are closed/seated.
RE: Sealing in Ricardo's sleeve valve engines
White, Graham. Allied Aircraft Piston Engines of World War II: History and Development of Frontline Aircraft Piston Engines Produced by Great Britain and the United States. Society of Automotive Engineers, 1995. ISBN: 9781560916550
Setright, L.J.K. Some Unusual Engines, Mechanical Engineering Publications. 1975. ISBN 0-85298-208-9.
Ricardo, Harry High Speed Internal Combustion Engines (out of print -- but their are paperback reprints available on the web.
Hunter , Marcus C. Inman. Rotary Valve Engines, John Wiley and Sons, 1946. This has a section on sleeve valve engines.
RICARDO consulting probably published some other sleeve valve info. They had proposed a sleeve valve diesel for light aircraft 10 or 15 years ago.
j2bprometheus
RE: Sealing in Ricardo's sleeve valve engines
Given that Ricardo did the early work in squish to control knock in side valve engines, it’s too bad that he got sidetracked since the big hemi aero engine could likely have gained from a faster fuel burn
RE: Sealing in Ricardo's sleeve valve engines
The brilliance of Ricardo's research was the influence of chamber geometry and charge motion on combustion efficiency.
RE: Sealing in Ricardo's sleeve valve engines
Tells me that maybe, possibly, we as designer/engineers have missed some un-realized advantages . . ., after all the world was flat and that was once fact, till some guy named Chris came along."
Chris? Who he? Johnny-Come-Lately, about 1,800 years late. The Greeks measured the size of a spherical Earth with an error on the order of 1% (by some interpretations of their system of measures). In fact, if Chris knew what the ancient Greeks knew about the size of the Earth and not knowing there were unimagined continents in his way, he might have figured it was too big for him to make the journey with the resources he had.
About WWII style sleeve valves:
It seemed the sleeve mechanism was more rpm-limited than pushrod poppet valves.
Single sleeves sealed extremely well since they totally encompassed the cylinder pressures and expanded against the fixed cylinder wall. This contrasts with other forms of rotary valve settups.
Sleeve valves needed much less oil than conventional 4-strokes because since the sleeve was constantly moving, the rings never stopped against the sleeve with no stiction problem as occurs in conventional engines especially at the top of the stroke where the top ring runs dry.
Also, the sleeve's motion distributes the oil film much better than what happens in the conventional engine.
Initially, the sleeve valve held about a 20% greater CR tolerance than poppet valves due to the hot exhaust valve. But, sodium cooling reduced that advantage.
The sleeve valve required better manufacturing precision making it a more expensive engine. Today that probably would not be a problem.
The piston ran hotter in the sleeve valve engine due to a somewhat less direct path to cooling.
RE: Sealing in Ricardo's sleeve valve engines
"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
RE: Sealing in Ricardo's sleeve valve engines
RE: Sealing in Ricardo's sleeve valve engines
je suis charlie
RE: Sealing in Ricardo's sleeve valve engines
The debate regarding the relative merits of sleeve valves versus poppet valves has been going on for over half a century. Here's all you need to know about the subject- Every engine designer knows all about sleeve valves, as does every engine manufacturer. These people are not stupid. So if sleeve valves were so much better than poppet valves, all modern IC piston engines would be using sleeve valves. But none of them use sleeve valves, and most of them use poppet valves. So what does that tell you?
It tells you that there are smaller markets for applications where sleeve-valve engines are optimal. To refine a sleeve valve engine to the extent that poppet valve engines have been refined would require quite a large budget. ROI is non existent.
Heres all you need to know about the subject- Engineers are focused on delivering the promises that the sales department already made to customers. Customers, marketing, bean counters, and sales departments have a huge influence over what engineering departments do.
If engineers could just build and manufacture whatever they wanted, engines would be much more interesting than they are right now.
"Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." ~ Joseph Stalin
RE: Sealing in Ricardo's sleeve valve engines
"....If engineers could just build and manufacture whatever they wanted, engines would be much more interesting than they are right now...."
And the follow-on has to be, ...until their companies go bankrupt...
RE: Sealing in Ricardo's sleeve valve engines
Great point! One big aspect of designing a product for commercial mass production is balancing conflicting requirements such as cost, performance, reliability, emissions, etc.
RE: Sealing in Ricardo's sleeve valve engines
I disagree with that first sentence. An engine designer (or any engineer for that mater) should learn and debate every aspect of such things. The sleeve valve has lost out to the poppet valve, but areas of superiority remain and these are things to consider when looking to improve any existing design. There is no need for "real engineers" if the mentality is "that's the way we've always done it".
je suis charlie
RE: Sealing in Ricardo's sleeve valve engines
The idea I was trying to communicate was that they are not able to unilaterally make platform changes on mass-produced engines. There are a lot of creative things that they can channel their energy into within the poppet-valve 4 cycle engine, for the time being. Customers and businesses are risk-aversive. The customers and other parts of the actual business act as checks and balances on what engineers execute.