Talk:Sleeve valve

message: "A recent SAE paper deals with a high speed,..."
I think a reference should be given which would obviate the "recent" - an increasingly vague term as the years go by. Dawright12 (talk) 10:25, 2 May 2011 (UTC)
thread_title: Modern Usage

message: I am currently researching sleeve valve engines.  Is there any body out there doing anything new with sleeve valves?
I would also like to hear from anyone with first hand experiance of the Bristol sleeve valve engines; i.e. pilots or engineers or those on the production line.
How reliable were they and were they realy oil thirsty?
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I didn't notice the post above until just now, and since you didn't register I don't have an account to reply to. Hopefully you'll see this.
The "oil thirsty" issues are not theoretical, they are entirely practical. Basically engines are nowhere near "pefectly circular" and as a result pistons to not fit cleanly into the cylinder. Instead the piston rings are placed around the piston and run until they scrape off the irregularities on the cylinder, which is deposited in the oil. This is called "breaking in" an engine, and you have to change the oil very soon after it is new.
With a sleeve valve the piston rings do not run on the cylinder wall, but the sleeve. This means that they scrape off a repeating N pattern in the sleeve as the piston moves up and down, so there is always somewhere on the sleeve that is not sealed. The oil blows past this hole and is burned.
However that was 50 years ago when a milimeter was considered the height of accuracy. With modern construction techniques and materials engines don't even have a breaking in period any more. The same techniques would "solve" the problems of the sleeve valve design, but there simply isn't any money in it.
Maury 00:15, 28 Dec 2003 (UTC)
replies: text: Most sleeve valve aero engines used a dry sump oil system with a separate oil tank, so oil consumption wasn't a problem, as one could just fit a bigger oil tank. A gallon or two of extra oil makes no meaningful difference when the normal oil capacity is measured in tens of gallons anyway.  — Preceding unsigned comment added by 80.7.147.13 (talk) 11:43, 6 April 2014 (UTC)

text: FYI in the Avro Lancaster each engine had a 37.5 gallon oil tank. The Hawker Typhoon had a 16 gallon one, the Hawker Sea Fury one of fourteen gallons. — Preceding unsigned comment added by 2.29.18.221 (talk) 14:51, 15 November 2015 (UTC)
replies: text: Bristol Centaurus oil consumption figures: at Max Cruising rpm = 10 pints per-hour, falling to 4 pints per-hour at lower rpm:   — Preceding unsigned comment added by 95.150.11.216 (talk) 16:13, 21 March 2016 (UTC)
thread_title: Sleeve Valves today

message: is there anyone who has a drawing of a sleeve valve
:Found a good description with drawings here:  
:GalFisk
Why is it that I always seem to be able to only find undersquare engines (bore diameter less than the piston travel) when looking at sleeve valve engines?  Does the sleeve valve engine only allow low speed operation or require excessive stroke to function well?  Would a high speed, substantially oversquare sleeve valve engine possibly exist?  -Dave  —Preceding unsigned comment added by Mrskyking737 (talk • contribs) 02:38, 3 July 2009 (UTC)
thread_title:  Sleeve valve 

message: How about starting with some basic things like telling us at least something about what it is first, before you get into advantages and history?  Gene Nygaard 07:29, 7 October 2006 (UTC)
thread_title: Cleanup

message: or just one? CorvetteZ51 14:05, 16 July 2007 (UTC)
thread_title:  sleeve, separate openings for I and E 

message: This article really needs a diagram to explain the mechanics involved at a glance. Drutt (talk) 16:27, 27 June 2008 (UTC)
thread_title:  Picture 

message: The 1953 Edition of the H Ricardo book on High-Speed Internal Combustion Engines tells in detail the history of materials used for both sleeve and cylinders, in liquid-cooled and air-cooled cylinders, and has also a section on petrol two-stroke engines, not suitable for automobile use because of instability below 40% of rated maximal power, and deals also with the issue of compression ignition engines. I fear breaking some copyright, but I'll summarize my reading of the chapter, sorry, I'm not engineer. 
Around 1922, the sleeve operating mechanism was changed from a white metal spherical joint, to bronze or aluminum. Sleeves were of cast iron, and then of steel, and pistons of aluminum. The S.V. working clearance was set in 0.0005 in. per inch of cylinder diameter (Figure checked). As long as the clearance between sleeve and cylinder was kept narrow, the oil film acted as an adequate mean to transmit heat from the piston to the cylinder wall. In 1925, aluminum cylinders were tested, and he tells that with this kind of material for cylinders, a carbon steel valve was good for small cylinders. For liquid cooled cylinders of 5 in. diameter or less, aluminum alloy with a cast iron or carbon steel sleeve worked well. Later on, he states that cylinders of silicon-aluminum alloys with sleeves of austenitic irons and steels looked promising. For air-cooled engines of 5 1/2 in. bore, he used silicon-aluminum alloy and a sleeve of austenitic steel, giving a difference in thermal expansion of 1.3:1. Austenitic steel proved bad, and a procedure was found of improving the surface of the bore of sleeve by rolling and shot-blasting. With a cast austenitic iron sleeve, they got a S.F.C. of 0.39 lb per B HP hour. 
When Bristol began to behave with a serious interest, they found that the austenitic-steel sleeve could be nitrogen hardened, but in the process, some sleeve distorsion was produced, and the very smooth and hard surface gave lubrication troubles, their solution was finding means to massaging the sleeve into truth after hardening, and a coarse honing process to break up the very smooth surface, that sir Harry Ricardo calls: "Satin finish". (Wankel engines had the same problem, solved among other ways with the Nikasil coating procedure, also the addition to lubricating oil of a solid state lubricating agent as Molybdenum Bisulfide -MoS2- is of help in maintainig lubrication under extreme Internal Combustion Engine's operating conditions). 
An article in a book about machining says that sleeves were machined using a solid inner cast while machining the outer side, plaster was used for this purpose, and a similar procedure while machining the inner part. Centrifugally cast nitrogen hardened austenitic steel sleeve with control over the manufacturing limits made unnecessary to use a silicon-aluminum alloy for cylinders. For the cylinder head, called 'Junk head', a composite copper-steel, cooled head was developed. A V12 version of S-S-V engine attained an S.F.C. of 0.38 lb. B HP hour. The appropriate sleeve strike was set in 30% of piston stroke, but in another publication, H Ricardo speaks about Sleeve stroke not exceeding 25% of piston stroke. A shorter sleeve stroke would give a greater inlet area, but reduced exhaust port area, and the opposite. In 2-stroke engines, the effective length of piston was determined to be equal to piston stroke less sleeve stroke, more or less 70% of piston stroke, and in these engines, the sleeve thickness was 0.125 in. 
An experimental unit used cast-iron cylinder with carbon steel sleeve, and also an open-ended carbon steel sleeve in an aluminum cylinder was considered. The compression-ignition engines used an open end sleeve, that in fact acted as another piston, participating in the transmission of the power to the crankshaft. Their 2-stroke engines had an oil use of 2 pint per hour, with dimensions of 4.8 in by 5.5 in. Also, a 0.55 carbon cast steel sleeve, directly on silicon-aluminum alloy cylinder was tested, that had the advantage of being machined from centrifugal steel castings, but this proved good for low B.M.E.P., if BMEP was above 200 x 2 lb. per sq. in., nitrogen hardened austenitic steel sleeves, with satin finish, were required for an air-cooled 4-cycle S-V engine. Bill Gunston, in his book on Development of Piston Aero Engines, points that it took R Fedden testing literally thousands of combinations of alloys and production methods to make flawless sleeves by centrifugal casting and then making them perfectly cylindrical. 
Nitrided sleeves had a life between 2'000 and 4'000 hrs, the wear of the top end of sleeve being the limiting factor (Poor lubrication?). This was acceptable for aircraft use, but would be a problem in commercial use. In most publications regarding SSV engines, just the Sleeve driving mechanism needed an specially devoted arrangement for lubricating oil supply. Looking in the international patent database Espacenet with the key words sleeve valve you'll retrieve most patents dealing with this kind of engines, all of free download. For example GB patent 305091 and GB288535 by British Continental, and also US2003743 by Fedden, deal with an arrangement for the sleeve driving mechanism; US patents 1820629 and US1814764 by A M Niven and US2319546 by R Insley deal with the method of making sleeves, so does US1820629 and US1814764 by A M Niven; GB555122 by Bristol and US1682702 by H J Edwars is on the coating of sleeves; GB704357 by H Ricardo on the way to make holes in sleeves; GB390434 and 329906 by British Continental are about counterbalancing of sleeves, and so does GB300434 by H Ricardo. GB202262 by Barr and Stroud is about general issues of SVs, and so is GB382571 and CA353554. GB668911 by H Ricardo is about special modifications for small size SV engines, and US2367963 by H Ricardo is about a SV 2-Stroke engine. Some additional discussion on a current SSV engine working unit can be found in YouTube, ChargerMiles007 videos and comments about it. That's all folks! --Jgrosay (talk) 18:43, 29 August 2013 (UTC)
replies: text: Bristol sleeve-valve engines were assembled using a colloidal graphite solution known as "Dag":  — Preceding unsigned comment added by 95.150.10.245 (talk) 16:59, 2 January 2017 (UTC)
thread_title: Some figures

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thread_title:  External links modified 

message: I feel like some of the statements in the Disadvantages section are Counteractive or ambiguous:
 "A serious issue with large single-sleeve aero-engines is that their maximum reliable rotational speed is limited to about 3,000 RPM,  but the M Hewland car engine was raced above 10,000 rpm without toil." - This says that this SSV engine has a sub-par redline, but says that this other SSV engine has a redline that is well above average. So is there a disadvantage or not? Either this should be removed, or rewritten to be more descriptive of this fact.
 "Some (Wifredo Ricart, Alfa-Romeo) feared the build-up of heat inside the cylinder, however Ricardo proved that if only a thin oil film is retained and working clearance between the sleeve and the cylinder barrel was kept small, moving sleeves are almost transparent to heat, actually transporting heat from upper to lower parts of the system." - Then if Ricardo proved this is not a problem, this Shouldn't be here! Saying this is an existing disadvantage is blatantly false! This should be removed or moved to the Historical section.
 "An inherent disadvantage is that the piston in its course partially obscures the ports, thus making it difficult for gases to flow during the crucial overlap between the intake and exhaust valve timing usual in modern engines. Mike Hewland admitted this was a problem at speeds above 10,000 rpm in his engines aimed at racing, but in the middle range, SSV was always better than a poppet valve engine. The 1954 printing of the book by Harry Ricardo: 'The high-speed internal combustion engine', and also some patents on sleeve valve production, point out that the available zone for ports in the sleeve depends on the type of sleeve drive and bore/stroke ratio; Ricardo tested successfully the 'open sleeve' concept in some two-stroke, compression ignition engines. It not only eliminated the head rings, but also allowed a reduction in height of the engine and head, thus reducing frontal area in an aircraft engine, the whole circumference of the sleeve being available for exhaust port area, and the sleeve acting in phase with the piston forming an annular piston with an area around 10% of that of the piston, that contributed to some 3% of power output through the sleeve driving mechanism to the crankshaft. The German-born engineer Max Bentele, after studying a British sleeve valve aero engine (probably a Hercules), complained that the arrangement required more than 100 gearwheels for the engine, too many for his taste." - So, SSV engines have limited viable cylinder dimensions, but then it mentions how this problem was (somewhat) solved by Ricardo, AGAIN. This Should be moved to the historical section. BUT the part with Max Bentele can stay, highlighting the disadvantage that SSV Engines can become more mechanically complex than conventional engine designs.                                                                                                                            - Now, I would have made these changes myself, but it felt it best to make this a discussion before we make any changes.  — Preceding unsigned comment added by 75.181.151.91 (talk) 01:30, 12 May 2018 (UTC)
thread_title:  Disadvantages?