[Vasya]

Packard Merlin.pdf

Variants
This is an incomplete 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 carburetors, engine block
construction, or arrangement of engine controls. All Merlin engines were "right hand
tractor", i.e. propeller rotated to the right viewed from rear, unless otherwise noted.
· Merlin II or III - 1,030 hp at 3,000 rpm at 5,500 ft. With 100 Octane fuel and
increased (+9lb/sq.in) Boost - 1,160 hp at 3,000 rpm at 12,250 ft.
· Merlin X - 1,130 hp at 3,000 rpm at 5,250 ft
· Merlin XX - 1,480 hp at 3,000 rpm at 6,000 ft.
· Merlin 32 - 1,645 hp at 3,000 rpm at 2,500 ft.
· Merlin 45 - 1,515 hp at 3,000 rpm at 11,000 ft.
· Merlin 46 - 1,415 hp at 3,000 rpm at 14,000 ft.
· Merlin 50.M- 1,585 hp at 3,000 rpm at 2,750 ft Low altitude version with
supercharger impeller "cropped" to 9.5 inches in diameter. Permitted boost was
+18 lb/sq.in. instead of +16 lb/sq.in. as on a normal Merlin 50 engine.
· Merlin 61 - fitted with a new two-speed two-stage supercharger providing
1,565 hp at 3,000 rpm at 12,250 ft, and 1,390 hp at 3,000 rpm 23,500 ft.
· Merlin 76 & 77 - 1,233 hp; Fitted with a two-speed, two-stage supercharger and a
Bendix-Stromberg carburetor. The odd-numbered mark drove a blower for
pressuring the cockpit.
· Merlin 130 & 131. - 2,070 hp; redesigned "slimline" versions made for the de
Havilland Hornet. Engine modified to decrease frontal area to minimum and was
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 carburetor. Maximum Boost was 25 lb. The
Merlin 131 had an additional idler gear in the reduction gear casing allowing
"reverse" (left hand tractor) rotation.
· Merlin 133 & 134 - 2,030 hp; Maximum Boost was lowered to 18 lb.