Editing Sleeve valve (section)

==Description==
A sleeve valve takes the form of one (or in the case of double sleeve valves, two) machined cylinders which fit concentrically between the piston and the cylinder block bore of an internal combustion engine having cross-flow induction/exhaust. These sleeves have inlet and exhaust ports machined in the periphery, analogous to a [[Two-stroke engine|two-stroke]] motor. Ports (apertures) in the periphery of the sleeves come into alignment with the cylinder's inlet and exhaust ports at the appropriate stages in the engine's cycle.

===Types of sleeve valve===
[[File:Knight sleeve-valve engine (Autocar Handbook, Ninth edition).jpg|thumb|right|Knight sleeve-valve engine|alt=A 4-cylinder car engine of 1919, sectioned through the cylinders to show the Knight sleeve valves.]]
The first successful sleeve valve was patented by [[Charles Yale Knight]], and used twin reciprocating sleeves per cylinder. It was used in some luxury automobiles, notably [[Willys]], Stearns, [[Daimler Company#Sleeve-valve engines|Daimler]], [[Daimler-Motoren-Gesellschaft#Automobiles|Mercedes-Benz]], [[Minerva (automobile)#Automobiles|Minerva]], [[Panhard]], [[Peugeot]] and [[Avions Voisin]]. [[Mors (automobile)|Mors]] adopted double sleeve-valve engines made by Minerva. The higher oil consumption<ref name="Autocar Handbook, Knight sleeve valve" >{{cite book
  |title=Autocar Handbook
  |publisher=[[Autocar (magazine)|The Autocar]]
  |edition=Ninth
  |year=c. 1919
  |pages=36–38
}}</ref> was heavily outweighed by the quietness of running and the very high mileages without servicing. Early poppet-valve systems required decarbonization at very low mileages and were prone to valve spring failure before the later advances in spring technology.
 
[[File:Argyll single sleeve-valve engine (Autocar Handbook, Ninth edition).jpg|thumb|right|Argyll single sleeve valve|alt=Diagram of the Argyll single sleeve valve, showing the complex shape of the multiple ports and the semi-rotary actuation]]
The [[Burt-McCollum]] sleeve valve was named for the two inventors who applied for similar patents within a few weeks of each other. The Burt system was an open sleeve type, driven from the crankshaft side, while the McCollum design had a sleeve in the head and upper part of the cylinder, and a more complex port arrangement (Source: 'Torque Meter' Magazine, AEHS). The design that entered production was more 'Burt' than 'McCollum.' It was used by the Scottish company [[Argyll (car)|Argyll]] for its cars,<ref name="Autocar Handbook, Argyll Sleeve Valve" >{{cite book
  |title=Autocar Handbook
  |publisher=[[Autocar (magazine)|The Autocar]]
  |edition=Ninth
  |year=c. 1919
  |pages=37–39
}}</ref> and was later adopted by [[Bristol Engine Company|Bristol]] for its radial aircraft engines and the Halford-designed Napier Sabre. It used a single sleeve driven by an eccentric from a timing axle set at 90 degrees to the cylinder axis.  Mechanically simpler and more rugged, the Burt-McCollum valve had the additional advantage of reducing oil consumption (compared with other sleeve valve designs), while retaining the combustion chambers and big, uncluttered, porting area established in the [[Knight Engine|Knight]] system.

A small number of designs used a "cuff" sleeve in the cylinder head instead of the cylinder proper,<ref name="Autocar, 1914" >{{cite journal
  |title=Cuff sleeve valves, description
  |journal=[[Autocar (magazine)|The Autocar]]
  |date=19 December 1914
}}</ref> providing a more "classic" layout compared with traditional poppet valve engines. This design also had the advantage of not having the piston within the sleeve, although in practice this appears to have had little practical value. On the downside, this arrangement limited the size of the ports to that of the cylinder head, whereas in-cylinder sleeves could have much larger ports.