valves. The Stutz Motor Company used a modified T-head with 16 valves, twin-spark ignition and aluminium pistons to produce 80 bhp (59 kW) at 2400 rpm from a 360.8 cid (5.8-liter) straight-4 (0.22 bhp per cubic inch). Over 2300 of these powerful early multi-valve engines were built. Stutz not only used them in their famous Bearcat sportscar but in their standard touring cars as well. The mono block White Motor Car engine developed 72 horsepower and less than 150 were built, only three are known to exist today. In 1919 Pierce-Arrow introduced its 524.8 cid (8.6-liter) straight-6 with 24 valves. The engine produced 48.6 bhp (0.09 bhp per cubic inch) and ran very quietly, which was an asset to the bootleggers of that era. Multi-valve engines continued to be popular in racing and sports engines. Robert M. Roof, the chief engineer for Laurel Motors, designed his multi-valve Roof Racing Overheads early in the 20th century. Type A 16-valve heads were successful in the teens, Type B was offered in 1918 and Type C 16-valve in 1923. Frank Lockhart drove a Type C overhead cam car to victory in Indiana in 1926. Bugatti also had developed a 1.5-liter OHV straight-4 with four valves per cylinder as far back as 1914 but did not use this engine until after World War I. It produced appr. 30 bhp (22.4 kW) at 2700 rpm (15.4 kW/liter or 0.34 bhp/cid). In the 1920 Voiturettes Grand Prix at Le Mans driver Ernest Friderich finished first in a Bugatti Type 13 with the 16-valve engine, averaging 91.96 km/h. Even more successful was Bugattis clean sweep of the first four places at Brescia in 1921. In honour of this memorable victory all 16-valve-engined Bugattis were dubbed Brescia. From 1920 through 1926 about 2000 were built. Peugeot had a triple overhead cam 5-valve Grand Prix car in 1921. Bentley used multi-valve engines from the beginning. The Bentley 3 Litre, introduced in 1921, used a monobloc straight-4 with aluminium pistons, pent-roof combustion chambers, twin spark ignition, SOHC, and four valves per cylinder. It produced appr. 70 bhp (0.38 bhp per cubic inch). The 1927 Bentley 4½ Litre was of similar engine design. The NA racing model offered 130 bhp (0.48 bhp per cubic inch) and the 1929 supercharged 4½ Litre (Blower Bentley) reached 240 bhp (0.89 bhp per cubic inch). The 1926 Bentley 6½ Litre added two cylinders to the