Between 1905 and 1913 Wolseley had two exceptionally talented engineering designers, Alfred Remington and Arthur Rowledge, in charge of the company's product design and development that made a formidable team together, but individually had their own specific areas of interest and different characters. Of the two, Rowledge appears to have been the most innovative, but not at the expense of practicality, and Remington more staid in his design work which was always backed up by careful research and development testing.
The company's development department must have carried out a lot of experimental work of which we have little knowledge and only by studying the company's patent applications can we discover fields of interest possibly being explored experimentally. Unfortunately, the patents in themselves do not prove that the company physically built working examples of these designs and speculation in this field can be dangerous. Most of this work would find its way into improved product design, but inevitably, some would fall by the wayside and never get beyond the drawing board.
A considerable amount of research appears to have been done into pressure charged engines to give improved output following the testing of an American Kessler engine which used air compressed in the crankcase to either scavenge the exhaust gas from the cylinder, or was admitted to augment the incoming charge of air and petrol, but Remington discovered the former use of little value. (Statement made by Remington to a meeting of the Institution of Automobile Engineers in May 1921)
Experiments appear to have been tried using pressurised charges of air and petrol in what appear to have been industrial semi-diesel engines and more trials carried out with crankcase compressed air admitted to augment the incoming charge, including an engine with a multi-port rotating valve the length of the cylinder block, and where each cylinder was separated in the crankcase to form individual pumps to produce and store air compressed in the crankcase, but none of these ideas ever found their way into the company's range of products.
The failure of exhaust valves was a common problem in the early days of motoring and Remington carried out extensive testing of valves including research into valve temperatures which led to the adoption of improvements in steel used for their manufacture, but at the same time, Remington and Rowledge were also investigating ways of abandoning troublesome poppet valves completely and began experimenting with sliding valves and sleeve valve engines.
Several Wolseley patents associated with sleeve valves were taken out between 1910 and 1912, patent numbers 16783, 20959, 831 and 8928, mainly covering the design of the mechanism to control the movement of the actual sleeve which required a very short but rapid movement and used a combination of cranks and levers actuated by a half engine speed shaft which replaced the conventional camshaft.
However, the first patent, 16783 of 1910, dealt specifically with the mechanism to operate a 'duplex piston valve', a single sliding valve which controlled the inlet and exhaust of individual cylinders of an engine, replacing the conventional poppet valves. This patent was intended as an improvement to a patented design taken out in 1909 by Henry Berry and George Mann, of Leeds, where the sliding valves were operated through a system of arms mounted on eccentrics carried on the engine crankshaft and half engine speed shaft.
The drawing to the left, from patent number 16,783, shows the Wolseley 'duplex piston valve' with a simplified and more directly acting mechanism to operate the valve, but still based on levers mounted on eccentrics carried on the crankshaft and engine half speed shaft.
Drawings from the Berry & Mann patent number 16,420 showing a cross sectional view of the engine in Figure 1 with the valve in the exhaust stroke position and a more detailed view of the sliding valve mechanism in Figure 3 with the valve positioned on the power stroke, together with an alternative operating mechanism in Figure 4 using a combination of levers carried on the half engine speed shaft eccentric and the connecting rod. The bottom left hand end of the pivoted links, 19, would be pivoted to a fixed point on the crankcase wall; a rather unwieldy looking arrangement.
This patent also included a basic drawing for a sleeve valve engine, drawing to the right, where the sparking plug is mounted centrally in the top of the combustion chamber and with the inlet and exhaust ports and manifolds located on opposite sides of the cylinders.
It would appear that Wolseley wanted to
remove itself from the complicated, and expensive, Berry & Mann eccentric mounted levers for the sleeve valve operating mechanism and this is one of five drawings from a 1912 Wolseley patent illustrating the mechanism required to operate the sleeve (D), via the engine half speed shaft (B) and a fixed pivot point on the crankcase (f), which avoided using the more commonly used crankshaft mounted arms
The first suspected proof of the company's involvement with sleeve valve engines appeared in some brief notes left by the works photographer when he took two photographs of a "SS sleeve model" in 1912 and took six pictures of a "S2 6 cylinder engine" in 1913.
To have two new engine types being run in four cars, clocking up proving mileage represented a substantial investment in product development and it may have been possible to put these into production by 1914/15, assuming no serious problems arose.
Unfortunately, no technical data was given, other than the steel sleeves were only one sixteenth of an inch thick and were working between the cast iron cylinders and cast iron pistons. From a production perspective it would have been more economical to have used some components from existing engines, such as crankshafts, con-rods and pistons, assuming that the eccentrically mounted arms carried by the crankshaft were dispensed with.
There was a general consensus at the time that sleeve valve engines worked more efficiently pressure charged than naturally aspirated and this drawing shows Wolseley's patented engine which included a means of introducing air compressed in the crankcase, or could be supplied via a Roots type blower, and the incoming charge could also be augmented by the use of a short secondary sleeve at the bottom of the cylinder which was rotated manually to uncover the additional port. It is not known if the four experimental engines incorporated this feature.
Mr Mann described the Wolseley engines as being made under Berry & Mann patents, but one would have expected Remington and Rowledge to have incorporated features of sufficiently different design, such as their patented sleeve operating mechanism, to ensure the engines avoided attracting royalty payments should they have entered production.
When war broke out in 1914 the development of these engines was obviously terminated and as a result of experience gained by the company building Hispano aero engines during the war the sleeve valve designs were abandoned in favour of overhead camshaft engines for the post war cars.
In 1921 Rowledge became chief assistant to Henry Royce at Rolls-Royce and in 1935 designed a superb 1,200 hp 24 cylinders "X" configuration sleeve valve aero engine with pressurised air cooling which was fitted to one of the company's private aircraft and, although the engine never went into production, was the favoured means of transport by aircrew and engineers alike.
This sectioned engine drawing to the right is from a Kessler patent dated 1907.
In 1913 Wolseley had four cars on test fitted with sleeve valve engines; two cars with 'SS' 4 cylinder engines and two cars with 'S2' 6 cylinder engines, these all being single sleeve designs. The 4 cylinder powered cars had covered 14,300 miles and 1,600 miles respectively, plus 500 hours of test bed development which would have been mostly on full power at speeds of 1,200 rpm to 1,800 rpm. (Prototype engines can spend thousands of hours on test bed development, but in-car road testing is essential) The 6 cylinder cars had covered 3,200 miles and 1,500 miles respectively. The 4 cylinder cars were later reported to be still running perfectly after 40,000 miles.
Several years have been spent trying to find more positive proof of the company's involvement with sleeve valve engines and this only surfaced recently with some of Remington's correspondence with Mr George Mann being discovered in proceedings of the Institution of Automobile Engineers published in 1923 after Remington's death.