Editing Rolls-Royce Merlin (section)

====Basic component overview (Merlin 61)====
''From Jane's'':<ref>Bridgman 1998, pp. 280–281.</ref>
; Cylinders
: Twelve cylinders consisting of high-carbon steel liners set in two, two-piece cylinder blocks of cast "[[Hiduminium|R.R.50]]" [[aluminium alloy]] having separate heads and skirts. Wet liners, ie. coolant in direct contact with external face of liners. Cylinder heads fitted with cast-iron inlet valve guides, [[phosphor bronze]] exhaust valve guides, and renewable "Silchrome" steel-alloy valve seats. Two diametrically opposed [[spark plug]]s protrude into each [[combustion chamber]].
; Pistons
: Machined from "[[Hiduminium|R.R.59]]" alloy [[forging]]s. Fully floating hollow [[gudgeon pin]]s of hardened nickel-chrome steel. Three [[Internal combustion engine#Compression ignition process|compression]] and one oil-control [[Piston ring|ring]] above the gudgeon pin, and one oil-control ring below.
; Connecting rods
: H-section machined nickel-steel forgings, each pair consisting of a plain and a forked [[Connecting rod|rod]]. The forked rod carries a nickel-steel bearing block which accommodates steel-backed lead-bronze-alloy bearing shells. The "small-end" of each rod houses a floating phosphor bronze [[Bushing (bearing)|bush]].
; Crankshaft
: One-piece, machined from a [[Nitriding|nitrogen-hardened]] nickel-chrome [[molybdenum]] steel forging. [[Engine balance|Statically and dynamically balanced]]. Seven main bearings and six throws.
; Crankcase
: Two aluminium-alloy castings joined together on the horizontal centreline. The upper portion bears the wheelcase, supercharger and accessories; and carries the cylinder blocks, crankshaft main bearings (split mild-steel shells lined with lead bronze alloy), and part of the housing for the [[Propeller speed reduction unit|airscrew reduction gear]]. The lower half forms an oil sump and carries the oil pumps and filters.
; Wheelcase
: Aluminium casting fitted to rear of crankcase. Houses drives to the camshafts, [[ignition magneto|magnetos]], coolant and [[oil pump (internal combustion engine)|oil pumps]], [[supercharger]], hand and electric [[Starter motor|starters]], and the electric [[Electrical generator|generator]].
; Valve gear
: Two inlet and two exhaust [[poppet valve]]s of "K.E.965" steel per cylinder. Both the inlet and exhaust valves have hardened "[[stellite]]d" ends; while the exhaust valves also have [[sodium]]-cooled stems, and heads protected with a "[[Brightray]]" (nickel-chromium) coating. Each valve is kept closed by a pair of concentric [[Coil spring|coil-springs]]. A single, seven-bearing camshaft, located on the top of each cylinder head operates 24 individual steel [[Rocker arm|rockers]]; 12 pivoting from a rocker shaft on the inner, intake side of the head to actuate the exhaust valves, the others pivoting from a shaft on the exhaust side of the head to actuate the inlet valves.