FOOTBALL-SIZE ENGINE

Britain's Amazing New Motor Distributed by Lost Tech. Do not copy, do not resell!

IMAGINE a football-size car engine with no vibration, no rods, crankshaft, valves, camshaft or radiator to go wrong or to slow down engine speed. No energy loss in converting linear motion to rotary motionpiston thrust to wheel-turning. No inertial loads on pistons as they change direction. "OK," you say, reasonably, "A turbine engine." But better than that, imagine an engine with all those low-stress advantages but with the low fuel consumption-per-horse-power-output of the internal combustion engine and without the tremendous heat problems of the turbine. That is the new Selwood orbital enginea piston engine with no reciprocating masses that is the most exciting development in internal combustion engines in a generation.

TWELVE-CYLINDER engine (in two bonks of six cylinders) has six spark plugs at each end, three exhaust ports per cylinder.

LONGITUDINAL CUTAWAY: static parts in color, rotating parts black and white.

From as far away as Japan, visitors come to Chandler's Ford, a small place in southern England near Southhamp-ton, to see a keen-eyed, gray-haired man pull a cord and start a small barrel-shaped object spinning on its axis. The unmuffled engine produces a quite bearable noise. It runs so smoothly that its stand isn't even bolted down.

This is the Selwood engine. The grey-haired man is its designer, Cecil Hughes, a veteran of World War I in which he served as a Royal Engineer. In his long career he has developed fuel injection systems for aircraft, fire control systems for battleships, improved hydraulic presses. For a long time he has been mulling over possibilities for improving the piston engine which has not undergone any major change in 30 years. When he hit on his present design he got enthusiastic backing from William Selwood, a successful self-made British businessman.

The design of the Selwood engine uses as pretty an engineering concept as any thought up by Leonardo da Vinci. The pistons in the whirling steel football don't actually reciprocatethey move in their own orbit, which is slightly different from that of the cylinders and the engine mass, without ever changing direction.

The entire Selwood engine rotates on a static shaft, which is shown in color in the drawing. The curved pistons pop back and forth in their curved double-ended cylinders. As each piston reaches its firing position one of its spark plugs contacts a static electrode. Gas ignites, the piston is driven to the other end of the cylinder and the spark plug at that end contacts the opposing static electrode. Gas ignites again and the piston is driven back.

The pistons are mounted on ball joints or, as the drawing calls them, piston mounting spheres. This mounting allows the ends of the piston to work back and forth, or up and down, depending on how you look at it. The spheres are between the legs of a spider, or the spokes of a wheel if you prefer. This spider or wheel rotates on the static shaft toobut not in the same plane as the engine. To understand the motion of the spider, cut a disc of cardboard and stab a pencil through its center, making a sort of spinner or top. Then push the disc so that it's cock-eyed on the pencil instead of at right angles to it. Now if you hold the pencil horizontally and twirl it you will see the action of the piston-bearing spider inside the Selwood engine. Rolling the pencil slowly, imagine that as the disc tilts to the right a piston at the top of the disc is fired leftward. At the same instant a piston at the bottom is fired to the right. You will see how the pistons keep the spider whirling.

This action f6rces the entire engine to rotate in the same direction as the off-vertical spider. But the

engine rotates in a vertical plane, at right angles to the shaft. The Selwood engine is called a 12-cylin-der engine because each of the six curved cylinders has two spark

plugs, two gas-oil inlets, two sets of exhaust ports and in effect does the job of two conventional cylinders. The engine rotates on the static shaft the one shown in color in the drawing. The power outlet shaft is

fixed to the engine and rotates with it. This is the shaft that will turn the drive wheels when the Selwood is put in a car.

It is a two-stroke engine using a gas-oil-air mixture. Its designer claims it can be developed in four-stroke and diesel versions. Gas and oil are fed to the cylinders through the static shaft. Cooling the present model is a simple matteras the engine spins the air combed through the cooling fins (see drawing) reduces the temperature of the hot metal.

The present Selwood engine is experimental. It weighs just over 100 pounds with all its accessories. With refinements in design and the use of light alloy metals this light weight can be cut down considerably. After a 350-hour test run it was stripped down and found in excellent conditionno signs of friction, overheating or distortion.

It is a marvel of compactness12 working cylinders of 42 cubic inches in a ten-inch diameter. A 490-cubic-inch model would fit in a 21-inch diameter.

Designer Hughes still has some hurdles ahead in the production of an orbital engine that will pull a family buggy. Will the engine take the greater heat that will develop when it is run at much higher power outputs? How will cooling be done at such speeds without excessive power loss?

For all of these future problems Hughes has his theoretical solutions. He is very confident that he will come through with a working car engine. He has been solving similar problems all his lifeand after all, the orbital engine itself was a mere theoretical possibility only a short while ago.

CURVED PISTONS, three-piece, hove ball-socket midsections. Hand holds piston end.

DESIGNER Cecil Hughes, left, and William R. Selwood conier in the Selwood workshop.

VIEW of engine with clamping ring removed shows pistons supported on ball Joints.