Reyre-Newson was a motorcycle produced in 1921 by S. C. Newson of Stamford Hill, London.
A machine was designed that had a single-cylinder ohv four-stroke engine of 63 x 80mm (249cc), in which the two vertically disposed valves were operated from a single face cam, located at the top of a vertical shaft. This was bevel-driven from the crankshaft on the offside.
The machine was successful in speed events as it was a neat lightweight, but the venture was short-lived.
Sectional drawing of the Newson engine, showing clearly the main details of the valve gear.
SILENT OVERHEAD VALVE GEAR
One Face Cam driven by a Vertical Shaft operates Both Valves.
MANY new types of overhead valve engines have appeared within the last few months but most of them have adhered to the practice of applying push rods, tappets, and internal or external cams.
The efficiency of this type of valve operating mechanism has been proved in competition, but there are many points on which it is open to improvement, and these the designer of the engine under review has set out to eliminate.
On the Newson engine, as it is called, a bevel-driven shaft rotates a circular face cam housed in a chamber above the cylinder head. A small bevel on the crankshaft drives a 2 to 1 pinion bolted to the tapered end of the vertical shaft, whilst keyed to the latter is another bevel, which drives a Thomson-Bennett magneto accessibly mounted on an aluminium plate cast integrally with the bevel housing. A ball bearing is located at either extremity of the shaft, the top one forming the base for the circular cam. Here another "eliminating" feature is found, since both valve rockers are operated from the same cam.
Friction is reduced by the use of a ball fixed beneath the rocker and lying in the cam channel. The axis of the rockers is provided with oil-retaining slots, whilst the lubrication of the bevels and shaft is effected by the oil vapour forced up the casting by the pressure in the crank case.
Conical valve springs are used, the cotter pins being retained by means of recessed spring cups. The valve lifter is simple in the extreme. A small lever and cam are located in a boss in the valve box, the cam lying directly beneath a small tongue on the rocker.
l 3/8 in. valves with a .4in. lift are used, and the I¼ in. diameter of the straight through induction and exhaust port is adequate to ensure the efficient and unobstructed passage of the gas. A cast iron cvlinder, having a bore and stroke of 63x80 mm. (248 c.c), is held to the crank case by four long bolts, which also retain the valve box in position.
The crankshaft and the 7in internal flywheels follow standard practice. A somewhat novel piston, however, is incorporated. It is of the slipper type, and narrow, deep rings of the aero engine variety are used, 5/16in roller bearings are fitted to the big end, whilst oil grooves fed from the crank case encircle the crankshaft.
Incorporated in a neat lightweight frame under the name of the Reyre-Newson, this power unit has already enjoyed success in various speed events.
The designer is Mr. S. C Newson,. of 32, Eastbourne Street, Stamford Hill, London, N.15.
Sources: Graces Guide, The Motor Cycle
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