Juge & Rolland Ornithoptère

Thr Ornithopter of Jean-Baptiste Juge and Paul Rolland was designed and realized during 1907 through 1909. In a January 1909 magazine article written by Paul Rolland in “L’Aérophile” about the machine, Rolland begins with a plea to the editor of “L’Aérophile” for a more powerful engine (40 hp), as the one available had insufficient power. In the last paragraph he mentions that the first tests were made without any publicity given. Additionally, he states that the first wing flaps or “coups d’ailes” rather, “have given us every satisfaction.” Jean-Baptiste Juge had filed a French patent on September 28, 1907 (published November 28, 1908) for an “Aviateur”, which is remarkably similar to the finished model. That this patent has only Juge as inventor, gives the impression at least, that he was the driving intellectual force behind the design of the machine.

JPX 4T X 75A

The 85 hp 4TX75/A engine is JAR certified and came with a 2 years or 1000 hr warranty. The magnetos fitted were Bendix.

4T X 75A
Cycle: 4 stroke
No cylinders: Flat 4
Bore: 95 mm
Stroke: 82 mm
Compression: 8.7
Displacement: 2325 cc
Cooling: Air
Ignition: Double magneto
Reduction: optional
Dimension: 755 x 680 x 520 mm
Weight: 78 kg
Max pwr: 85 hp at 3000 rpm
Max torque: 202 at 2900 rpm
Fuel consumption: 190/220 G/hp/hr
Price 1998: 70 940 Fttc

JPX PUL 425

Two JPX PUL 425s mounted on a Lazair 2

The JPX PUL 425, also called simply the JPX 425, is a French twin-cylinder, horizontally opposed, two-stroke aircraft engine.

The engine was produced only until the company went out of business in the early 1990s. The company was re-formed but the engine remains out of production and unsupported for parts.

The engine has two cylinders in a horizontally-opposed configuration, with cooling fins on the cylinders. The single ignition system uses a coil and points. Fuel is metered by a single Tillotson butterfly-type carburetor. Starting is by a recoil starter system with electric start as an option.

The 425 has a redline rpm of 4600 and does not use a reduction drive. Its weight of just 38 lb (17 kg) gives the engine a high power-to-weight ratio.

Applications:
Latécoère 225
Lazair 2
Lazair SS
Lazair Series III
Zenair Zipper

Specifications
Type: twin-cylinder, two-stroke engine
Displacement: 424 cc (25.87 cu inches)
Dry weight: 38 lb (17 kg)
Fuel system: Tillotson butterfly-type carburetor
Oil system: premixed oil and fuel
Cooling system: air cooled
Power output: 26 hp (19 kW) at 4600 rpm