Aston Martin RB6 engine

Aston Martin RB6
Overview
Manufacturer	Aston Martin
Production	1959–1960
Layout
Configuration	95° I-6, naturally-aspirated
Displacement	2.5 L (153 cu in)
Cylinder bore	83 mm (3.3 in)
Piston stroke	90 mm (3.5 in)
Valvetrain	24-valve, DOHC, four-valves per cylinder
Compression ratio	9.8:1[1]
Combustion
Fuel system	Carburetor
Oil system	Dry sump
Output
Power output	250–280 hp (186–209 kW)
Torque output	208–235 lb⋅ft (282–319 N⋅m)
Dimensions
Dry weight	203 kg (448 lb)

The Aston Martin RB6 is a 2.5-litre, naturally-aspirated, inline-6 racing engine, developed and designed by Aston Martin for Formula One racing; used between 1959 and 1960.^[2] The RB6 also shared the basic double-overhead camshaft straight-6 Aston Martin engine design with its brethren, but sleeved to reduce its capacity to 2.5-litres. Although Tadek Marek's design was a reliable and powerful unit in its 3.7-litre road car form, the reduced capacity racing motor was hard-pressed to cope with the heavy chassis and poor aerodynamics, and frequent engine failures blighted the DBR4's brief racing career. Aston Martin claimed a 280 bhp (210 kW) output for the DBR4's engine. However, it was common practice at the time to overquote engine power, and a more realistic value is closer to 250 bhp (190 kW). This value is still higher than that provided by the Coventry Climax FPF straight-4, used by contemporary manufacturers such as Lotus and Cooper, but the Aston Martin engine weighed appreciably more. The engine drove the rear wheels through a proprietary David Brown gearbox, provided by Aston Martin's owners.^[3][4][5]

The DBR5's engine was smaller and lighter. The new engine modifications meant that the power output was finally close to the figure originally claimed by the Aston Martin workshop.^{[6][7][8][9][10]}