The Green D.4 was a four-cylinder

watercooled Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and non ...

inline

piston engine A reciprocating engine, more often known as a piston engine, is a heat engine that uses one or more Reciprocating motion, reciprocating pistons to convert high temperature and high pressure into a Circular motion, rotating motion. This article ...

produced by the

Green Engine Co __NOTOC__ The Green Engine Co was a British engine company founded by Gustavus Green in Bexhill to sell engines of his design. He flourished especially as a designer of aeroplane engines during the first two decades of the 20th century. The eng ...

in the UK in 1909. It produced about 60 hp (45 kW) and played an important role in the development of British aviation before World War I.

Design

The Green D.4 was a natural development of the Green C.4, a 30-35 hp engine used by some early aviators in the UK, such as

Roe Roe, ( ) or hard roe, is the fully ripe internal egg masses in the ovaries, or the released external egg masses, of fish and certain marine animals such as shrimp, scallop, sea urchins and squid. As a seafood, roe is used both as a cooking, c ...

and the

Short Brothers Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...

. It was an inline, water-cooled 4-cylinder piston engine with characteristic Green features: cast-steel single-piece cylinders and cylinder heads, two valves per cylinder driven by an overhead camshaft, white metal crankshaft bearings and copper water jackets, rubber-sealed to allow for differential expansion. Increases in bore and stroke gave the D.4 more than twice the swept volume of the C.4 and roughly doubled its power. The cast-steel cylinders, individually machined inside and out, were mounted separately onto a flat-sided aluminium

crankcase A crankcase is the housing in a reciprocating engine, piston engine that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, res ...

. They were fastened down by long bolts between them, which reached into the crankcase to support the four inner

crankshaft A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...

bearings. The main bearings were in the crankcase ends, and the ball race was designed to allow either pusher or

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...

operation. A

flywheel A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, a ...

was fitted to the output shaft. Thin cylindrical copper water jackets surrounded the cylinders almost to their base, where a rubber ring, located by a circumferential groove in the cylinder, provided a sliding water seal that allowed for the differential thermal contraction of copper and steel. Cooling water was fed to these jackets by an engine-driven pump via a horizontal tube on the low right side of the engine, assuming a tractor orientation, and fed to the

radiator A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

by another tube on the top left. A single jet

Zenith The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The z ...

carburettor with a remote float chamber fed a double branched

inlet manifold An inlet manifold or intake manifold (in American English) is the part of an internal combustion engine that supplies the fuel/ air mixture to the cylinders. The word ''manifold'' comes from the Old English word ''manigfeald'' (from the Anglo- ...

on the right; the plugs, also set in the cylinder walls, were on the same side, below and angled to the inlets. The exhaust ports were on the left side, angled forwards. A crankshaft driven Bosch

magneto A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, ...

at the rear provided the plugs' high voltage supply. The overhead

camshaft A camshaft is a shaft that contains a row of pointed cams in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition syst ...

was also driven from the crankshaft via worm gears and a vertical shaft at the rear of the engine. The camshaft operated the valves by

rockers Rocker or rockers may refer to: Places *Rocker, Montana, a neighborhood in Butte, Montana, United States People *Rocker, a British drummer, formerly of The Flatmates *Fermin Rocker (1907–2004), painter and illustrator *John Rocker (born 1974), ...

with rollers on their camshaft ends and adjusting screws at the other. Lubricating oil was mechanically pumped through cast-in channels in the crankcase to all the crankshaft bearings. The camshaft was contained in an oil tight sleeve. The D.4 was usually described as a 50-60 hp engine, sometimes as 60 hp, 65 hp or 60-70 hp. The type designation D.4 was rarely used at the time.

Operational history

Green's engines were noted for their reliability, and Green reinforced that reputation with entries into Government competitions; in 1910 the D.4 won the £1.000 prize donated to the winner by Patrick Alexander. There was a maximum power test, the D.4 achieving 67.8 hp at 1,210 rpm, but the emphasis was on endurance: the engine had to produce two non-stop 12 hr runs and average more than 58.5 hp. In the event, the D.4 averaged 61.6 hp with few signs of wear on inspection afterwards. Up to 1912 the Green D.4 was the only all-British aircraft engine capable of producing 60 hp,ENV, who offered a 60 hp motor, were a joint Anglo-French concern so when prizes were offered for flights or races for all-British aircraft, the Green was the only choice. The best known example is that of Moore-Brabazon in his Short Biplane No. 2, winning the £1,000 ''Daily Mail'' prize in 1910 for a circular 1 mile flight by a British pilot in an all-British aeroplane. The British Empire Michelin Trophies (no.1 for speed and no.2 for distance) between 1910 and 1913 were also all-British aircraft competitions. Six of the seven winners were powered by Green engines, showing their dominance and reliability. The winners of all four of the 1910-11 contests, three of Cody's aircraft plus Moore Brabazon's Short S.2, were D.4 powered. Cody's D.4 also powered his entry to fourth place in the 1911 ''Daily Mail'' Circuit of Britain competition, a distance of 1,010 miles. That engine, flown over 7,000 miles, was exhibited at the 1913 Olympia Aero Show. Despite its pre-war success, neither the Green D.4 nor other Green models played a part in the war, in which the lighter, air-cooled French engines of

Le Rhône Le Rhône was the name given to a series of Rotary engine, rotary aircraft engines built between 1910 and 1920. Le Rhône series engines were originally sold by the Gnome et Rhône#Le Rhône, Société des Moteurs Le Rhône and, following a 1914 ...

Clerget Clerget-Blin (full name being ''Société Clerget-Blin et Cie'') was a French precision engineering company formed in 1913 by the engineer and inventor Pierre Clerget and industrialist Eugène Blin. In 1939, the company was absorbed into the ' ...

and

Gnome A gnome () is a mythological creature and diminutive spirit in Renaissance magic and alchemy, introduced by Paracelsus in the 16th century and widely adopted by authors, including those of modern fantasy literature. They are typically depict ...

were extensively used.

Variants

* A long stroke (152 mm) development gave 65 hp (48 kW) at 1250 rpm, but seems not to have flown.

Applications

Sources: &

Specifications

References

External links

''Flight'', March 12, 1910 - "British Flight Engines: The Green".
Covers both the C.4 and D.4 engine types. {{Green aeroengines 1900s aircraft piston engines Green aircraft engines