Daimler-Knight four-cylinder engine, 1909.
© Science Museum / Science & Society Picture Library
A 22 hp sleeve valve engine, 96 mm bore x 130 mm stroke, with one cylinder sectioned. This petrol engine was patented by C Y Knight in 1905 and 1908, and adopted by the Daimler Motor Co as their standard engine in 1909. The engine differs from ordinary petrol engines in that it has a pair of sliding sleeve valves fitted between the piston and the cylinder wall instead of the more usual mushroom tappet valves. This had the effect of enabling the motor to run silently and also allowed higher speeds to be attained as a consequence of the rapid opening and closing of the valves.