NEW TWO-STROKE ENGINE.

Putaruru Press, Volume VI, Issue 229, 22 March 1928, Page 7

NEW TWO-STROKE ENGINE.

REDUCES GEAR-SHIFTING. Novel Supercharger. I A . | A new air-cooled super-charged two-stroke motor-car engine has been I invented by W. L. Adams, who is also I the inventor of a springless suspension device. Those three adjectives j air-cooied, supercharged, two- ’ stroke—are sufficient to stamp this engine as something out of the ordinary. There are no air-cooled engines of British design for motor-cars, and I only one well-known one in America; j supercharging has been little used except for racing engines, and the twoj stroke engine has found little favour j except for a few motor-cycle engines. | By using six cylinders which are | set V-shaped at an angle of 60 de- | grees, the effect of the two-stroke system is to give the torque of a 12cylinder, 4-stroke engine. Usually in an engine of this kind there are no valves, the inlet and exhaust being taken through ports cut in the cylinder walls, which are closed and opened by the pistons, but Mr. Adams uses a rotary valve to admit the mixture, and the ports for the exhaust. A Novel Blower. The supercharging and air-cooling are combined in a blower of novel design. Unlike most air-cooled engines, Mr. Adams houses his cylinders under a cowl, a high-speed fan being used to create a strong air current past their fins. This also warms the air which is on its way to do its supercharging work. Now comes the explanation as to ) how gear changing is largely obviated with this engine. If the car is driven all-out up the hill until more power is necessary, it can be obtained by pressing the accelerator pedal until a stronger spring is actuated which withdraws the clutch and disconnects the blower from the crank shaft. Thus the engine is no Ipnger called .upon to drive the blower, and j a dynamotor takes on the work of helping the engine. This dynamotor, which is placed ju3t outside the blower, is connected to the outer end of the blower shaft. The blower is speeded up by the electrical drive and makes more supercharging pressure and stronger cooling air current. Starting Operations. When starting the engine from cold, the accelerator pedal is pressed fully down, which brings the dynamo into action, starts the blower, and also delivers a supercharged mixture to the cylinders. When the pedal is released the spinning blower gives ’ sufficient revolutions to the engine to start it.

Another novel point in this engine is the use of a turbine wheel to utilise the waste power coming from the exhaust ports and also to act as a silencer. As Mr. Adams pointed out, with the engine running at 2000 revolutions per minute there would be no fewer than 200 explosions per second or 12,000 per minute. He had found that there was no apparent increase of back pressure from the use of this turbine. Connecting rods are of duralumin and finned to dissipate heat, while the cylinder blocks are of steel-lined aluminum.