Classic Cars
Introduction
During the 34 years between 1905 and 1939 , there was considerable development in every element of both interior and exterior car design. Engines were initially slow-revving, having single or twin-cylinders. These only developed a limited horse-power, which is why the more prestigious cars came to have a very high cylinder capacity. The 1915 Packard introduced the fashion for very powerful cars. The “Twin Six” had twelve cylinders, and was the first American model to have aluminum pistons. At that time there was a great variety of types, especially among the vehicles with smaller cylinder capacities. There were air or water-cooled engines mounted either in the middle (even under the floor), ‘V’ or opposed, operating on the 2 or 4 stroke cycle. Then during the 1930s, 8 cylinders in line became a common arrangement until this was replaced by 8 cylinders in ‘V’ formation.
Hot bulb ignition was replaced by the coil, or ignition by means of high or low tension magnetos. Side valves operated overhead valves, sometimes operated by a double camshaft. In time the ‘L’ head developed into the ‘T’ (with side valves operated by two separated camshafts, originally adopted because they were easier to maintain). In the ‘L’ the valves were situated on the same side, and the spark plug was mounted beside the inlet valve, so as to be cooled by the incoming mixture. Cars which initially only had two-speed gearing acquired three or four gear. The system of gearing was soon to by considerably change, however. The early movable gear=wheels gave way to a proper gearbox, the invention of Emile Levassor. This consisted of a sliding gear-train providing two or three gear ratios plus reverse.
The electric gearshift made its first appearance on the Cadillac in 1912. The introduction of removable wheels represented another important advance. The Isotta-Fraschini was the first car to brakes on the front wheels in 1910. For a long time, however, front-mounted brakes were considered to be dangerous and did not come into widespread use until the mid 1920s. In 1921 a Duesenberg was developed with revolutionary hydraulic brakes which were adapted three years later on the Chrysler. At the same time, during this period, car body work saw a progressive development in structure. Open cars gradually were altered to have enclosed bodies for greater passenger comfort.



