Paxman Ventura
| Paxman Ventura | |
|---|---|
| Overview | |
| Manufacturer | Davey, Paxman & Co |
| Designer | Geoffrey Bone |
| Also called | YJ |
| Production | 1960–1992 |
| Layout | |
| Configuration | 60° vee: V6, V8, V12 or V16 |
| Displacement | V6: 39.42 litres (2,410 cu in) V8: 52.56 litres (3,210 cu in) V12: 78.84 litres (4,810 cu in) V16: 105.12 litres (6,410 cu in) |
| Cylinder bore | 7.75 inches (197 mm) |
| Piston stroke | 8.50 inches (216 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Aluminium alloy |
| Valvetrain | OHV, 4 per cylinder |
| Compression ratio | 13:1 |
| Combustion | |
| Operating principle | four-stroke turbo-charged high-speed diesel |
| Fuel system | 2x CAV monobloc fuel injection pump (4x on V16), 11,500 psi (790 bar) (total) direct injection |
| Fuel type | diesel |
| Output | |
| Power output | V12: 1,200–1,500 brake horsepower (890–1,120 kW; 1,200–1,500 PS) at 1,500 rpm V16: 1,600–1,870 brake horsepower (1,190–1,390 kW; 1,620–1,900 PS) at 1,500 rpm |
| Chronology | |
| Predecessor | Paxman YH, direct injection medium-speed diesel |
| Successor | Paxman Valenta |
The Paxman Ventura is an internal combustion diesel engine for railway locomotives, built by Davey, Paxman & Co.
The type YJ or Ventura was developed in the mid-1950s as Davey, Paxman's first high-speed diesel engine. With a view to the forthcoming modernisation and dieselisation of British Railways (BR), it was intended as a successor to Paxman's existing medium-speed engine, the direct injection YH. High-speed engines offered higher power-to-weight ratios, which in turn allowed locomotives to have a lower axle loading and greater route availability. The YJ was to have a weight of less than four tons for a 1,200 horsepower (890 kilowatts; 1,200 metric horsepower) V12, with versions of V6, V8, V12, and V16 configurations. Their construction and reliable use though required more sophisticated manufacture than previously, with better metallurgy and balancing of the moving parts for faster running and a stiffer crankcase to avoid vibration.
A total of 1098 engines were built by Paxman in Colchester, England (147 V6, 190 V8, 426 V12, and 335 V16); a further 37 were built under licence in Italy by Motori Breda of Milan for the D.343 Class locomotives of the Italian State Railways.