I have a Dawson engine, gearbox and radiator, and can supply some information to interest Mr. M. F. Dawson.
The car was manufactured during 1920 and 1921 by the Dawson Car Co., Ltd., Coventry. The freehold and plant were acquired at the end of 1921 by the Triumph Cycle Co. for the production of the Triumph car.
My engine is number 166-10-20. The block was cast in 1919. It is a four-cylinder unit of 69 by 120 mm. bore and stroke (1,795 c.c.). The crankcase and sump are of cast aluminium, the detachable head and block being cast iron. A three-bearing crankshaft drives a single overhead camshaft through vertical shaft and skew gears at the front. The camshaft operates eight vertical in-line tulip valves through the medium of adjustable caps screwed to the valves and secured by lockouts. There are two inlet ports on the right and four exhaust ports on the left. The connecting-rods are Steel H-section forgings, and are stamped with the date and bearing sizes. The pistons are domed aluminium with three gas rings and fully floating gudgeon pins.
From the vertical shaft a pair of skew gears operate a horizontal shaft at right angles to the crankshaft axis, on the right of which is the coupling for the platform-mounted magneto. From the left of the horizontal shaft another pair of skew gears rotate a shaft with a pulley for the fan at the front and a flexible coupling for the cradle-mounted dynamo at the rear. The starter is similarly mounted on the right of the engine. A further pair of skew gears operates a vertical shaft to the gear-type oil pump in the base of the sump. Lubrication is by a series of troughs for the crankshaft bearings and by pressure to the camshaft.
There is a fixed starting handle. The separate three-speed gearbox has a universally-jointed lever working in a right-hand gate, and an internal-expanding transmission brake. Drive to the gearbox is through a cone clutch, the flywheel having a bolted-on starter ring. The connecting shaft has one fabric coupling.
The radiator is similar to that of a 3-litre Bentley and has a bulldog badge.
I am, Yours, etc.,
P.W. Evans – Bristol.
Letters: November 2018
Nothing changes No doubt other readers have had the same thought, but one sentence from a recent letter – “This era of subservient team-mates is not racing, it’s manipulation of…
Matters of moment, December 1961
THE R.A.C. RALLY The 1960 R.A.C. Rally was a comparatively mild affair over A and B roads; this year's event was just the reverse and really proved the merit of…
Lunch with... Henri Pescarolo
I’m sitting outside a bistro in the warm Paris sunshine, enjoying a pre-lunch aperitif with Henri Pescarolo. Not for nothing is this man known as Monsieur Le Mans. He has…