Mathis Vega 42

Émile E. C. Mathis had begun designing and producing motor-cars from 1910. Société Mathis Aviation, formed in 1937, began designing aircraft engines, initially with the large and complex Vega.[1]

The Vega (and the similar Vesta) had a 2-piece Aluminium-alloy crankcase, 7 Aluminium-alloy cylinder blocks, with one-piece Aluminium-alloy heads and steel cylinder liners. A 6-throw crankshaft ran in 7 plain bearings.

Development continued after the war, culminating in the 119.4 l (7,290 cu in) 3,700 kW (5,000 hp) Vesta 42, which did not reach the hardware stage before Mathis closed its doors.[1]

The Vega engines were run on test-beds, and some sources indicate the engine was flown 100 hours in a test bed aircraft during 1939, but no details of flight testing survive.[1]

Vega 42A

Initial version of the engine first run in 1938, rated 1,700 kW (2,300 hp) at 3,000 rpm. Two examples and a full-scale mock-up are reported to have been built.[1]

Vega 42B

An improved variant, under development in 1940. Completed and unfinished engines were hidden from invading German forces, in the Pyrenees.[1]

Vega 42D

An enlarged capacity version which became the Vesta 42.[1]

Vega 42E

Post WWII development rated at 2,100 kW (2,800 hp) for take-off.

Vesta 42

An enlarged Vega, developed from 1942, with similar configuration, but 158 mm (6.22 in) bore, 145 mm (5.71 in) stroke and 119.4 l (7,290 cu in) displacement, rated at 3,700 kW (5,000 hp).[1][2]

Data from Old Machine Press: Mathis Vega 42-Cylinder Aircraft Engine,[1] Aircraft engines of the World 1946[2]

General characteristics

• Type: 42 cylinder in-line radial engine (6 7-cylinder banks)
• Bore: 125 mm (4.92 in)
• Stroke: 115 mm (4.53 in)
• Displacement: 59.3 l (3,620 cu in)
• Length: 1,520 mm (59.84 in)
• Diameter: 1,070 mm (42.13 in)
• Dry weight: 1,180 kg (2,600 lb)
  • Maximum Brake Mean Effective Power (b.m.e.p.) 13.4 kg/cm² (191 psi)

Components

• Valvetrain: 1 exhaust and 1 inlet valve per cylinder driven by 7x single overhead camshafts (SOHC)
• Supercharger: Gear-driven single-stage driven at 5.53:1, with automatic boost control.
• Fuel system: 1x Zenith 160 2-barrel downdraught carburetor
• Fuel type: 100/130 Octane aviation gasolene
• Oil system: Pressure feed at 690 kPa (100 psi), dry sump using 25.1 cs (0.00418 min) viscosity oil
• Cooling system: liquid-cooled
• Reduction gear: Epicyclic bevel reduction gear at 0.42:1

Performance

• Power output: Take-off:2,100 kW (2,800 hp) at 3,200 rpm at 1.2 m (3 ft 11 in) +8.6lb boost

Normal:1,700 kW (2,300 hp) at 3,000 rpm at 2,000 m (6,600 ft)

Cruising:1,300 kW (1,700 hp) at 2,500 rpm at 2,000 m (6,600 ft)

• Specific power: 35 kW/l (0.77 hp/cu in)
• Compression ratio: 6.5
• Specific fuel consumption: 0.292 kg/kW (0.48 lb/hp) per hour, cruising
• Oil consumption: 0.011 kg/kW (0.018 lb/hp) per hour, cruising
• Power-to-weight ratio: 0.57 kg/kW (0.93 lb/hp)

• Armstrong Siddeley Deerhound

• Bodemer, Alfred; Laugier, Robert (1987). les Moteurs à pistons aeronautiques français (1900/1960) vol.2 (in French) (1st ed.). Editions lariviere. ISBN 978-2862482279.
• Cuny, Jean; Raymond, Danel (1980). L'Aviation française de bombardement et de renseignement : 1918-1940 (in French). Larivière.
• "The Mathis 42E 00: A New French Six-bank In-line Engine of 4,000-5,000 h.p." Flight. XLVIII (1915): 257. 6 September 1945. Retrieved 5 December 2018.
• "Here and There: Mathis Multi". Flight. XLVII (1897). 3 May 1945. Retrieved 5 December 2018.

• LES MOTEURS MATHIS
• WW2 AIRCRAFT.NET :MATHIS 'Vega' 42-Cylinder French Aero-Engine