Editing Straight-four engine (section)

== Usage in racing cars ==
[[File:BMW F1 Engine M12 M13.JPG|thumb|right |1980s [[BMW M12|BMW M12/13]] Formula One engine]]

Many early racing cars used straight-four engines, however the Peugeot engine which won the [[1913 Indianapolis 500]] was a highly influential engine. Designed by [[Ernest Henry (engineer)|Ernest Henry]], this engine had [[Overhead_camshaft_engine#Double_overhead_camshaft|double overhead camshafts]] (DOHC) with four valves per cylinder, a layout that would become the standard until today for racing inline-four engines.<ref name=Ludvigsen>{{cite book|last=Ludvigsen|first=Karl|author-link=Karl Ludvigsen|title=Classic Racing Engines|publisher=Haynes Publishing| year=2001|isbn=1-85960-649-0}}</ref>{{refpage|pp. 14–17}}

Amongst the engines inspired by the Peugeot design was the [[Harry Arminius Miller|Miller engine]], which was a successful racing engine through the 1920s and early 1930s. The Miller engine evolved into the [[Offenhauser|Offenhauser engine]] which had a highly successful spanning from 1933 until 1981, including five straight victories at the Indianapolis 500 from 1971 to 1976.<ref name=Ludvigsen/>{{refpage|pp. 182–185}}

Many cars produced for the pre-WWII [[Voiturette (F2)|voiturette]] [[Grand Prix motor racing]] category used inline-four engine designs. 1.5&nbsp;L [[supercharger|supercharged]] engines found their way into cars such as the [[Maserati 4CL]] and various [[English Racing Automobiles]] (ERA) models. These were resurrected after the war, and formed the foundation of what was later to become [[Formula One]], although the straight-eight supercharged Alfettas would dominate the early years of F1.

Another engine that played an important role in racing history is the straight-four [[Ferrari]] engine designed by [[Aurelio Lampredi]]. This engine was originally designed as a 2&nbsp;L [[Formula 2]] engine for the Ferrari 500, but evolved to 2.5&nbsp;L to compete in [[Formula One]] in the Ferrari 625.<ref name=Ludvigsen/>{{refpage|pp. 78–81, 86–89}} For [[sports car]] racing, capacity was increased up to 3.4&nbsp;L for the Ferrari 860 Monza.

The [[Coventry Climax]] straight-four engine was also a very successful racing engine, which began life as a 1.5&nbsp;litre Formula 2 engine. Enlarged to 2.0&nbsp;litres for Formula One in 1958, it evolved into the large 2,495&nbsp;cc FPF that won the Formula One championship in [[Cooper Car Company|Cooper]]'s chassis in 1959 and 1960.<ref name=Ludvigsen/>{{refpage|pp. 130–133}}

In Formula One, the 1980s were dominated by the 1,500&nbsp;cc turbocharged cars. The [[BMW M12|BMW M12/13]] engine was notable for the era for its high boost pressures and performance. The cast iron block was based on a standard road car block and powered the F1 cars of Brabham, Arrows and Benetton and won the world championship in 1983. The 1986 version of the engine was said to produce about {{convert|1300|hp|kW|round=50|abbr=on}} in qualifying trim, at 5.5 bar of turbo boost.<ref>{{cite web|url=http://www.gurneyflap.com/bmwturbof1engine.html |title=BMW Turbo F1 Engine |publisher=Gurneyflap.com |access-date=2010-09-13}}</ref>