Engines and superchargers engineered by a Swiss designer in Germany, Italy, France and GB from before WWI into the late 1930s. These were fitted to BMW, DKW and AJS motorcycles.
Born September 1, 1882, died Winterthur, December 8, 1934. Darmstadt, Catholic, from Tablat (now the municipality of St. Gallen) and from 1887 from Winterthur. Son of Johann, painter and master craftsman, and Margaretha, née Schmidt. 1) Maria Scaler, Italian, 2) Charlotte Noack, German. Apprenticeship as a mechanic at Gebrüder Sulzer AG, 1906 diploma as a mechanical engineer at the Winterthur Technical College.
From 1910 to 1914, he worked as an engine designer for racing driver Felice Nazzaro and at Fiat in Turin. From 1919 to 1923, he was a manager at the Argus Motor Works in Berlin, then a freelance consultant, including for the automobile and motorcycle company DKW.
From 1928 to 1929, he founded the Société française des moteurs Zoller in Paris and a racing cooperative. With over 150 patents, he was a pioneer in the development of the two-stroke engine as a rotary piston compressor, but was unsuccessful with the twin-piston engine for racing cars.
Source: Peter Müller-Grieshaber: "Zoller, Arnold," in Historical Dictionary of Switzerland (HLS), version dated March 5, 2012.
"Les premiers essais faits Montlhéry ont donné les résultats les plus encourageants et l'on envisage la création d'une 500 cmc." (The first tests made Montlhéry have given the most encouraging results and the creation of a 500 cmc.)
Sources: Moto Revue, Dec 1927.
ARNOLD ZOLLER, OF BERLIN, GERMANY
TWO-STROKE CYCLE ENGINE
Patented Feb. 4, 1930
Application Filed February 6, 1923, Serial NO. 617,418, and in Germany January 31, 1922.
My invention relates to internal combustion engines of the two-stroke type and it is an object of my invention to provide an engine of the kind described which may be supercharged without the necessity of introducing the supercharging mixture at high pressure. To this end I so time the operation of the means controlling the exhaust of the products of combustion and the intake of fresh combustible mixture that during the expansion stroke of the piston the exhaust. controlling means, for instance, an exhaust valve of the usual type, are opened at a given crank angle in front of the lower dead centre iston, finishing the scavenging period, and hat the intake ports are closed on the compression stroke when. the piston has moved hrough a given angle past its lower dead centre position. During this part of the stroke, more mixture is admitted for super-charging the engine. With this operation the products of combustion are released on the expansion stroke when the piston is at a given distance from the lower dead centre...
NEW TWO-STROKE ENGINE.
1500cc Unit Developing 200 h.p.
According to a report to which prominence has been given a new and amazingly efficient two-stroke engine has been designed in Germany for contest purposes. It is well known that Germany is determined to participate vigorously in European contests this year, and, in addition to such well-known makes as the Mercedes-Benz and Porsche cars, several so-called mystery models will probably come forward. The new engine has been developed by Arnold Zoller, a Swiss engineer, now resident in Germany, and who is acknowledged to be a foremost expert in the two-stroke field. He was the designer of several of the new engines seen at the recent Berlin motor show. It is said that he is now completing a special car which will have a more or less conventional chassis, but will be powered with a novel sort of two-stroke engine.
Both crankcase and cylinder are of aluminium alloy and are cast integrally. There are 12 bores in two rows of six, and the cylinders carry steel liners. The detachable head is so made that there is one combustion chamber for each pair of cylinders. The cylinders on one side carry the exhaust ports, and those on the opposite side the inlet ports, both sets of ports being opened and closed by the movement of the aluminium piston in each cylinder The pistons which operate in the cylinders having the exhaust ports work dliectly on the crankshaft the others are linked to the connecting rods of the former at the big-end bearings the angle being so arranged that the exhaust pistons open and close their ports earlier than do the inlet pistons This arrangement ensures good scavenging of the exhaust gases and is also conducive to efficient supercharging.
An important feature of the engine is the supercharging apparatus which consists of two Zoller superchargers driven by gearing from the crankshaft. In front of these the water pump is installed and the rate of circulation of the water is so high that a cooling fan is unnecessary. The superchargers draw the mixture from a dual down-draught carburettor and feed it through a water-cooled pipe to the inlet ports at a pressure of 21 lb The total displacement of this 12-cylinder engine is about 1500 c c but it is claimed that because of the dual cylinder arrangement the engine can be supercharged to a degree which will ensure a power output equal at the same rate of revolution to that of a 6000 c c unit It is stated that the developed power at 5500 rpm is 200 bhp.
It is also proposed to raise that performance by fitting an exhaust gas turbine by which means it is hoped that an additional 60 b h p will be gained. The built-up crankshaft runs in roller bearings and the big-ends are fitted with needle roller bearings. The degree of supercharging can be varied by the use of alternative gear sets in the supercharger drive and by that means the engine can be made suitable for ordinary sports models as well as for record-breaking work. It is also reported that the inventor is planning to produce a 750c.c. unit for racing cars built on the same lines and that the distribution of the new Zoller cars will not be restricted but that they will be available for export.
The Sydney Morning Herald Tue 22 May 1934 (Trove NLA)
