The Renault 4P, also called the Renault Bengali Junior, was a series of air-cooled 4-cylinder inverted in-line 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 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.
Renault 4PsThe initial version with 115 mm (4.53 in) bore and 140 mm (5.51 in) stroke, delivered 71 kW (95 hp)
Renault 4PaRenault 4Pbupright 71 kW (95 hp) / 61 kg (135 lb) - Caudron Luciole
Renault 4PbiInverted development of the Pb retaining the 115 mm (4.53 in) bore
Renault 4PcFurther development of the Ps retaining the 115 mm (4.53 in) bore
Renault 4Pciinverted 4Pc
Renault 4PdeRenault 4PdiInverted, 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 4PeiInverted, rated at 110 kW (150 hp) for take-off, the 4Pei entered production before WWII
Renault 4PgiInverted lower rated version, giving 78 kW (105 hp) for take-off, using 73-octane fuel.
Renault 4PoRenault 4Poi100 kW (140 hp) with fuel injection.
Renault 4P-01Postwar production version of the 4Pei, rated at 145 hp (108 kW) for take-off.
Renault 4P-03As the 4P-01 but with an inverted flight Zenith carburettor
Renault 4P-05As for the 4P-03 but with a modified oil system
Renault 4P-07As for the 4P-03 but with a modified carburettor
MV-4Licence 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.
Data from
Type: 4-cylinder naturally aspirated air-cooled inverted in-line piston aircraft engineBore: 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)Valvetrain: Pushrod-actuated, single intake and single exhaust valve per cylinderFuel system: 1x Zenith 601GS down-draught carburettorFuel type: 80 Octane petrolOil system: Pressure fed, 3.0 kg/cm2 (43 lbf/in2), dry sumpCooling system: AirPower output:
145 hp (108 kW) at 2,450 rpm @ take-off140 hp (100 kW) at 2,400 rpm @ sea-level normal110 hp (82 kW) at 2,200 rpm @ sea-level cruiseSpecific power: 17.15 kW/L (0.38 hp/in3)Compression ratio: 5.8:1Specific fuel consumption: 0.186 kg/kW/hrOil consumption: 0.005 kg/kW/hrPower-to-weight ratio: 0.74 kW/kg