
First production Merlin II delivered 10 August 1937. Spitfire Mk.I, Defiant Mk.I, Hurricane Mk.I, Sea Hurricane Mk.I, Battle Mk.I It was first widely delivered as the 1,030-horsepower (770 kW) Merlin II in 1938, and production was quickly ramped up. 400 Hour flight endurance tests carried out at RAE July 1937 Acceptance test 22 September 1937. ( Merlin II) Replaced "ramp" cylinder heads with parallel pattern heads (valves parallel to the cylinder) scaled up from the Kestrel engine. The Fairey Battle was the first production aircraft to be powered by the Merlin I and first flew on 10 March 1936. The Merlin continued with the "ramp" head, but this was not a success and only 172 were made. This became the first production engine and was designated as the Merlin I. Failed military 100-hour test in March 1936. Passed 50-hour civil test in December 1935. First flight in Hawker Horsley 21 December 1935. ĭevelopment of Merlin B Crankcase and cylinder blocks became three separate castings with bolt-on cylinder heads. "Ramp" cylinder heads ( inlet valves were at a 45- degree angle to the cylinder). Two built, ethylene glycol liquid cooling system introduced.

Two built, passed bench Type Testing in July 1934. The initial design using an evaporative cooling system.

the propeller rotated clockwise viewed from behind, unless otherwise noted.ħ40 hp (552 kW) at 12,000-foot (3,700 m) equivalent All Merlin engines were "right hand tractor", i.e. Engines of a similar power output were typically assigned different model numbers based on supercharger or propeller gear ratios, differences in cooling system or carburettors, engine block construction, starting system, or arrangement of engine controls. This is a list of Rolls-Royce Merlin variants.
