Bullet:
Very interesting. According to Jane's....the Spit IX's engine was more HP but the Spit VIII and Spit XVI had the same engines but were manufactured by different companies. From this chart it would appear to me that in-game Seafire is grossly underpowered vs. the HP it claims to have had. Understanding the power to weight ratio because it was a carrier launched and landed a/c it's obviously going to be heavier.
Main article: List of Rolls-Royce Merlin variants
This is a summary list of representative Merlin variants. Engines of the same power output were typically assigned different model numbers based on supercharger or propeller gear ratios, differences in cooling system or carburettors, engine block construction, or arrangement of engine controls.[67] All but the Merlin 131 and 134 engines were "right-hand tractor", i.e. the propeller rotated to the right when viewed from the rear.
Data from Bridgman (Jane's)[68] unless otherwise noted:
Merlin II or III
1,030 hp (775 kW) at 3,000 rpm at 5,500 ft (1,680 m) using + 6 psi boost (41 kPa gauge; or an absolute pressure of 144 kPa or 1.41 atm); Merlin III fitted with "universal" propeller shaft able to mount either de Havilland or Rotol propellers,[69]
1,310 hp (977 kW) at 3,000 rpm at 9,000 ft (2,700 m) with 100 octane fuel and +12 psi boost (83 kPa gauge; or an absolute pressure of 184 kPa or 1.82 atm) (Merlin III);[43] both used in the Boulton Paul Defiant, Hurricane Mk.I, Spitfire Mk.I fighters, and Fairey Battle light bomber.[70]
Merlin X
1,130 hp (840 kW) at 3,000 rpm at 5,250 ft (1,525 m); used in Halifax Mk.I, Wellington Mk.II, and Whitley Mk.V bombers.
Preserved Merlin XX at the Royal Air Force MuseumMerlin XII
1,150 hp (860 kW); fitted with Coffman engine starter; first version to use 70/30% water/glycol coolant rather than 100% glycol. Fitted to Spitfire Mk. II.[69]
Merlin XX
1,480 hp (1,105 kW) at 3,000 rpm at 6,000 ft (1,830 m); used in Beaufighter Mk.II and Hurricane Mk.II fighters, Halifax Mk.II and Lancaster Mk.I bombers.
Merlin 32
1,645 hp (1,230 kW) at 3,000 rpm at 2,500 ft (760 m); used mainly in Fleet Air Arm aircraft; used in Barracuda Mk.II torpedo bomber and Seafire IIc. Also Hawker Hurricane Mk V and Spitfire P.R Mk XIII.[69] and
Merlin 45
1,515 hp (1,130 kW) at 3,000 rpm at 11,000 ft (3,353 m); used in Spitfire Mk.V, PR.Mk.IV and PR.Mk.VII, Seafire Ib and IIc.
Merlin 47
1,415 hp (1,055 kW) at 3,000 rpm at 14,000 ft (4,270 m); high-altitude version used in Spitfire H.F Mk VI. Adapted with a Marshall compressor (often called a "blower") to pressurise the cockpit.
Merlin 50.M
1,585 hp (1,182 kW) at 3,000 rpm at 3,800 ft (1,160 m); low-altitude version with supercharger impeller "cropped" to 9.5 inches (240 mm) in diameter. Permitted boost was +18 psi (125 kPa gauge; or an absolute pressure of 225 kPa or 2.2 atm) instead of +16 psi (110 kPa gauge; or an absolute pressure of 210 kPa or 2.08 atm) on a normal Merlin 50 engine. A "negative-g" carburettor was fitted.[71][72]
Merlin 61
1,565 hp (1,170 kW) at 3,000 rpm at 12,250 ft (3,740 m)
1,390 hp (1,035 kW) at 3,000 rpm at 23,500 ft (7,170 m); fitted with a new two-speed two-stage supercharger providing increased power at medium to high altitudes; used in Spitfire F. Mk IX, and P.R.Mk XI.[73] First British production variant to incorporate two-piece cylinder blocks designed by Rolls-Royce for Packard Merlin.[74]
Merlin 66
1,720 hp (1,283 kW) at 5,750 ft (1,752 m) using +18 psi boost (124 kPa gauge; or an absolute pressure of 225 kPa or 1.2 atm); low-altitude version of Merlin 61. Fitted with a Bendix-Stromberg anti-g carburettor;[75] used in Spitfire L.F Mk VIII and L.F Mk IX.[71]
Merlin 76/77
1,233 hp (920 kW); used in the Westland Welkin high-altitude fighter and some later Spitfire and Mosquito variants. Fitted with a two-speed, two-stage supercharger and a Bendix-Stromberg carburettor. The odd-numbered mark drove a blower for pressurising the cockpit.
Merlin 130/131
2,060 hp (1,536 kW); redesigned "slimline" versions for the de Havilland Hornet. Engine modified to decrease frontal area to a minimum and was the first Merlin series to use down-draught induction systems. Coolant pump moved from the bottom of the engine to the starboard side. Two-speed, two-stage supercharger and S.U. injection carburettor. Maximum boost was 25 psi (170 kPa gauge; or an absolute pressure of 270 kPa or 2.7 atm). The Merlin 131 had an additional idler gear in the reduction gear casing allowing "reverse" (left-hand tractor) rotation. The Merlin 130 was fitted in the starboard nacelle, Merlin 131 in the port nacelle on production Hornets.[76]
Merlin 133/134
2,030 hp (1,514 kW); derated variants of 130/131 used in Sea Hornet F. Mk. 20, N.F. Mk. 21 and P.R. Mk. 22. Maximum boost was lowered to +18 psi gauge (230 kPa or 2.2 atm absolute).
Merlin 266
The prefix "2" indicates engines built by Packard, otherwise as Merlin 66, optimised for low-altitude operation. Fitted to the Spitfire Mk. XVI.[71]
