Renault 4P

4P
Type	Air-cooled 4-cylinder inverted inline piston engine
National origin	France
Manufacturer	Renault

The Renault 4P, also called the Renault Bengali Junior, was a series of air-cooled 4-cylinder inverted inline aero engines designed and built in France from 1927, which produced from 95 hp (71 kW) to 150 hp (110 kW).

Design and development

Charles Lindbergh's Atlantic Ocean crossing in 1927 inspired Renault to enter the light aero-engine market to diversify the range of engines they offered. The resulting Renault 4Ps, with 115 mm (4.5 in) bore and 140 mm (5.5 in) stroke, delivered 95 hp (71 kW) and proved popular, later versions powering several record-breaking light aircraft.

Developed by Charles-Edmond Serre, by 1931 the 6.3-litre 4Pdi had evolved to give 110 hp (82 kW) to 120 hp (89 kW), with the adoption of 120 mm (4.7 in) bore steel cylinder liners, aluminium alloy cylinder heads attached by long studs to the crankcase, Duralumin connecting rods and magnesium alloy crankcase.

The 4Pei was produced in the USSR, with local equipment and features from the MV-6, as the Voronezh MV-4 (Motor Vozdushniy / Motor Voronezhskiy - air-cooled engine / Voronezh built engine {correct interpretation is unclear}).

In 1946 production of the Renault 4P-01 resumed at the SNECMA factory at Arnage, until 1949, with at least 762 engines manufactured.

Variants

Renault 4Ps: The initial version with 115 mm (4.53 in) bore and 140 mm (5.51 in) stroke, delivered 71 kW (95 hp)
Renault 4Pa
Renault 4Pb: upright 71 kW (95 hp) / 298 lb (135 kg) - Caudron Luciole
Renault 4Pbi: Inverted development of the Pb retaining the 115 mm (4.53 in) bore
Renault 4Pc: Further development of the Ps retaining the 115 mm (4.53 in) bore
Renault 4Pci: inverted 4Pc
Renault 4Pde
Renault 4Pdi: Inverted, introduced 120 mm (4.72 in) bore steel cylinder liners, aluminium alloy cylinder heads attached by long studs to the crankcase, Duralumin connecting rods and magnesium alloy crankcase. 110 hp / 150 kg - Hanriot 16, 120 hp / 155 kg - Caudron Phalène
Renault 4Pei: Inverted, rated at 110 kW (150 hp) for take-off, the 4Pei entered production before WWII^[1]
Renault 4Pfi
Renault 4Pgi: Inverted lower rated version, giving 78 kW (105 hp) for take-off, using 73-octane fuel.^[1]
Renault 4Po
Renault 4Poi: 100 kW (140 hp) with fuel injection.
Renault 4P-01: Postwar production version of the 4Pei, rated at 145 hp (108 kW) for take-off.^[2]
Renault 4P-03: As the 4P-01 but with an inverted flight Zenith carburettor^[2]
Renault 4P-05: As for the 4P-03 but with a modified oil system^[2]
Renault 4P-07: As for the 4P-03 but with a modified carburettor^[2]
MV-4: Licence production of a 110 kW (150 hp) Renault 4Pei variant in the USSR at the Voronezh factory. 180+ were built in 1939 before production ceased, due to a shortage of indigenous carburettors.^[3]

Applications

Specifications (Renault 4P-01)

Data from Aircraft engines of the World 1946.^[2]

General characteristics

Type: 4-cylinder naturally aspirated air-cooled inverted in-line piston aircraft engine
Bore: 120 mm (4.7 in)
Stroke: 140 mm (5.5 in)
Displacement: 6.33 L (386 cu in)
Length: 1,729 mm (68.1 in)
Width: 480 mm (19 in)
Height: 708 mm (27.9 in)
Dry weight: 147 kg (324 lb)

Components

Valvetrain: Pushrod-actuated, single intake and single exhaust valve per cylinder
Fuel system: 1x Zenith 601GS down-draught carburettor
Fuel type: 80 Octane petrol
Oil system: Pressure fed, 3.0 kg/cm² (43 lbf/in²), dry sump
Cooling system: Air

Performance

Power output:
145 hp (108 kW) at 2,450 rpm at take-off
140 hp (100 kW) at 2,400 rpm at sea-level normal
110 hp (82 kW) at 2,200 rpm at sea-level cruise
Specific power: 17.15 kW/L (0.38 hp/in³)
Compression ratio: 5.8:1
Specific fuel consumption: 0.186 kg/kW/hr
Oil consumption: 0.005 kg/kW/hr
Power-to-weight ratio: 0.74 kW/kg

References

^ ^a ^b Wilkinson, Paul H. (1945). Aircraft Engines of the World 1945 (3rd ed.). New York: Paul H. Wilkinson.
^ ^a ^b ^c ^d ^e Wilkuinson, Paul H. (1946). Aircraft Engines of the World 1946 (Revised ed.). London: Sir Isaac Pitman & Sons.
^ Kotelnikov, Vladimir (2005). Russian Piston Aero Engines. Marlborough: The Crowood Press Ltd. pp. 164–165. ISBN 978-1-86126-702-3.

Gérard Hartmann, Les Moteurs d'avion Renault
Wilkinson, Paul H.. Aircraft Engines of the World 1945 3rd edition. Paul H. Wilkinson. 1945. New York.
Wilkinson, Paul H.. Aircraft Engines of the World 1946 revised edition. Sir Isaac Pitman & Sons Ltd.. 1946. London.

[Wilkinson_45-1] Wilkinson, Paul H. (1945). Aircraft Engines of the World 1945 (3rd ed.). New York: Paul H. Wilkinson.

[Wilkinson_46-2] Wilkuinson, Paul H. (1946). Aircraft Engines of the World 1946 (Revised ed.). London: Sir Isaac Pitman & Sons.

[Kotelnikov-3] Kotelnikov, Vladimir (2005). Russian Piston Aero Engines. Marlborough: The Crowood Press Ltd. pp. 164–165. ISBN 978-1-86126-702-3.

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