The Burt-McCollum Single-Sleeve Valve (SSV) engine
The Background
The Burt-McCollum sleeve valve was named for the two inventors who applied for similar patents within a few weeks of each other - Peter Burt and James Harry Keighly McCollum.
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. The design that entered production was more 'Burt' than 'McCollum,' and was used by the Scottish company Argyll for its cars, and later was adopted by Bristol for its radial aircraft engines, used a single sleeve which rotated around 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 to other sleeve valve designs), while retaining the combustion chambers and big, uncluttered, porting area possible in the Knight system.
The Burt-McCollum sleeve valve consisted of a single sleeve, which was given a combination of up-and-down and partial rotary motion. It was developed around 1909 and was first used in the 1911 Argyll car.
Patents for the single-sleeve-valve engine
- 1909 June 22nd. No. 14,629 granted to James Harry Keighly McCollum, for an Invention of Improvements in and relation to Valves and Valve Gear for Internal Combustion Engines
- 1909 August 9th. No. 18,140 of 1909 granted to Peter Burt and ARGYLLS Limited, for an Invention of an Improved Internal Combustion Engine
- 1909 November 24th. No. 27,327 of 1909 granted to James Harry Keighly McCollum, for an Invention of Improvements in the Valves and Valve Gear of Internal Combustion Engines
- 1910 September 27th. No. 22,396 of 1910 granted to James Harry Keighly McCollum, for an Invention of Improvements in Valve Gear for Internal Combustion Engines
- 1915 July 15th. No. 10,304 granted to Peter Burt, for an Invention of Improvements in the Cylinders of Internal Combustion Engines
Commercial Application
When the Argyll car was launched in 1911, the Knight and Kilbourne Co immediately brought a case against Argyll for infringement of their original 1905 patent. This patent described an engine with a single moving sleeve, whereas the Daimler engines being built at the time were based on the 1908 Knight patent which had engines with two moving sleeves. As part of the litigation an engine was built according to the 1905 specification and developed no more than a fraction of the rated RAC horsepower. This fact coupled with other legal and technical arguments led the judge to rule, at the end of July 1912, that the holders of the original Knight patent could not be supported in their claim that it gave them master rights encompassing the Argyll design. It is reported that litigation by the owners of the Knight patents cost Argyll ₤50,000, perhaps one of the reasons for the temporary shutdown of their plant.
Barr and Stroud of Anniesland, Glasgow, also licensed the SSV design, and made small versions of the engines that they marketed to motorcycle companies. In an advertisement in Motor Cycle magazine in 1922 Barr & Stroud promoted their 350cc Sleeve Valve engine and listed Beardmore-Precision, Diamond, Edmund, and Royal Scot as motorcycle manufacturers offering it. This engine had been described in the March edition as the 'Burt' engine.
Grindlay-Peerless started producing a SSV Barr & Stroud engined 999cc V-twin in 1923 and later added a 499cc single SSV as well as the 350cc. Some small SSV auxiliary boat engines and electric generators were build in the UK, prepared for burning 'paraffin' from start, or after a bit of heat-up with more complex fuels.
1925 Extension of the patents: 'In the Matter of Letters Patents No. 14,629 of 1909, bearing date 22nd June. 1909, granted to JAMES HARRY KEIGHLY McCOLLUM, for an Invention of Improvements in and relation to Valves and Valve Gear for Internal Combustion Engines; No. 18,140 of 1909, bearing date 6th August, 1909, granted to PETER BURT AND ARGYLLS Limited, for an Invention of an Improved Internal Combustion Engine; No. 27,327 of 1909, bearing date 24th November, 1909, granted to JAMES HARRY KEIGHLY McCOLLUM, for an Invention of Improvements in the Valves and Valve Gear of Internal Combustion Engines; No. 22,396 of 1910, bearing date 27th September, 1910, granted to JAMES HARRY KEIGHLY McCOLLUM, for an Invention of Improvements in Valve Gear for Internal Combustion Engines; No. 10,304 of 1915, bearing date 15th July, 1915, granted to PETER BURT, for an Invention of Improvements in the Cylinders of Internal Combustion Engines; and in the Matter of The Patents and Designs Acts, 1907 and 1919......Peter Burt, of Hollybank, Bothwell, Lanarkshire, and Joseph Smith Burt, of 20, Queensborough gardens, Glasgow, have by Originating Summons dated the 20th day of December, 1924, applied for an Order that the term of the above mentioned Letters Patent may be extended for a further term of 5 years, ...'[1]
A number of Sleeve Valve aircraft engines were developed following a seminal 1927 research paper from the RAE by Harry Ricardo. This paper outlined the advantages of the sleeve valve and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp (1,100 kW). Napier and Bristolsbegan the development of Sleeve-Valve engines that would eventually result in limited production of two of the most powerful piston engines in the world: the Napier Sabre and Bristol Centaurus. These represented the greatest success for Single Sleeve Valves (SSV) which were also used in the Rolls-Royce Eagle engines. The SSV system also reduced the high oil consumption associated with the Knight double sleeve valve.
The Continental Motors Corporation of Detroit purchased the patents from Wallace (Glasgow), and around the years of the Great Depression, developed prototypes of Single Sleeve-Valve engines for a range of applications, from cars to trains to airplanes, and thought that production would be easier, and costs would be lower, than its counterpart poppet valve engines. Due to the financial problems of Continental, this line of engines never entered production.
Potentially the most powerful of all Sleeve-Valve engines (though it never reached production) was the Rolls-Royce Crecy V-12 (oddly, using a 90-degree V-angle), two-stroke, direct-injected, turbocharged (force-scavenged) aero-engine of 26.1 litres capacity. It achieved a very high specific output, and surprisingly good specific fuel consumption (SFC). In 1945 the single-cylinder test-engine (Ricardo E65) produced the equivalent of 5,000 HP (192 BHP/Litre) when water injected, although the full V12 would probably have been initially type rated at circa 2,500 hp (1,900 kW). Sir Harry Ricardo, who specified the layout and design goals, felt that a reliable 4,000 HP military rating would be possible. Ricardo was constantly frustrated during the war with Rolls-Royce's efforts. Hives & RR were very much focused on their Merlin, Griffon then Eagle and finally Whittle's jets, which all had a clearly defined production purpose. Ricardo and Tizard eventually realized that the Crecy would never get the development attention it deserved unless it was specified for installation in a particular aircraft but by 1945, their "Spitfire on steroids" concept of a rapidly climbing interceptor powered by the lightweight Crecy engine had become an aircraft without a purpose.
Following World War II, the sleeve valve principle was used less; Roy Fedden, who had been involved in very early S-V research, built some flat-six Single Sleeve-Valve engines intended for general aviation around 1947; after this, just the French SNECMA company produced some SSV engines under Bristol licence that were installed in the Noratlas transport airplane, also another transport aircraft, the Azor built by the Spanish CASA installed SSV Bristol engines post-WWII. Bristol sleeve valve engines were used however during the post-war air transport boom, in the Vickers Viking and related military Varsity and Valetta, Airspeed Ambassador, used on BEA's European routes, and Handley Page Hermes (and related military Hastings), and Short Solent airliners and the Bristol Freighter and Superfreighter. The Centaurus was also used in the military Hawker Sea Fury, Blackburn Firebrand, Bristol Brigand and the Fairey Spearfish. The poppet valve's previous problems with sealing and wear had been remedied by the use of better materials and the inertia problems with the use of large valves were reduced by using several smaller valves instead, giving increased flow area and reduced mass, and the exhaust valve hot spot by Sodium-cooled valves. Up to that point, the single sleeve valve had won every contest against the poppet valve in comparison of power to displacement. The difficulty of nitride hardening, then finish-grinding the sleeve valve for truing the circularity, may have been a factor in its lack of commercial application.