From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Specification sheet for a White 12-cylinder horizontally opposed bus engine.
| Identifier | ExFiles\Box 134\1\ scan0172 | |
| Date | 2nd December 1939 guessed | |
| WHITE 12 CYLINDER HORIZONTALLY OPPOSED BUS ENGINE No of cylinders 12 Bore & Stroke 4¼ x 4¼ Piston displacement 681 cu: in: Max: BHP‡ 210 @ 3000 RPM Compression ratio 5.88 to 1 Max: torque 500 lbs at 1200 RPM Weight without carburetter or ignition 2200 lbs OVERALL DIMENSIONS Width 38½" Height 21¼" Length 69½" Valve DIMENSIONS Inlet Exhaust Max: head dia; 1.88 1.75 Min: port dia; 1.62 1.62 Lift .381 .381 Stem dia; .401 .401 Seat angle 30° 45° PISTON DIMENSIONS Length 4.40 Gudgeon pin 1.18 dia x 3.62 long Weight (bushed alum alloy piston complete with pin and five rings) 44 ozs CONNECTING RODS Length (centre to centre) 8 1/32 Weight (with bush and cap) 51.5 oz CRANKSHAFT 7 main bearings (balance weights used) Main bearing dia: and length Front 2.87 x 2.18 Rear 2.87 x 2.50 Crank pin dia: and length 2.43 x 3.00 Side by side Con-rods. TAS{T. Allan Swinden}/ | ||