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).
Technical specifications for gearbox ratios, gears, camshaft, rear axle, differential, and petrol pump.
| Identifier | ExFiles\Box 126\2\ scan0131 | |
| Date | 18th November 1938 guessed | |
| -3- RATIOS. Top. 4.09 : 1 Third. 5.99 : 1 Second. 10.1 : 1 First. 15.13: 1 Reverse 15.13: 1 All Gears except 1st. and reverse are spiral. PARTICULARS OF GEARS. Shaft Centres = 3.395. 1st.Speed Driver. 17 Teeth. 49/64" wide. 20°Obliquity. 8/10 DP. 1st.Speed Driven. 37 " 23/32" " 20° " 8/10 DP. 2nd.Speed Driver. 22 " 57/64" " 20° " 27° 15'Helix. 9 DP. 2nd.Speed Driven. 32 " 29/32" " 20° " 27° 15' " 9 DP. 3rd.Speed Driver. 29 " 57/64" " 20° " 27° 15' " 9 DP. 3rd.Speed Driven. 25 " 29/32" " 20° " 27° 15' " 9 DP. Reverse Pinion. 23 " 1.3/32" " 20° " 8/10 DP. CAMSHAFT. Camshaft machined only on Bearings and Cam Profiles. Camshaft Drive by Reynolds Duplex Chain 3/8" Pitch. See SS.{S. Smith}220, Made of Low Carbon Steel Thus:- Carbon0.09%, Manganese 0.62% Nickel 0.11%,Chromium.less than 0.3% REAR AXLE. Ratio 11/45. SS.{S. Smith}241-4 and SS.{S. Smith}254. Spiral Bevels with a four Pinion Bevel Differential. See SS.{S. Smith}241-4 and SS.{S. Smith}254. Dia of Crown Wheel = 9.225". Ratio. 45 x 11. Hypoid. Nil. Back Lash in Gears.= .015" Bore of Lockheed Cylinder = 1.125" Dia. DIFFERENTIAL. Bevel Pinion. 11 teeth. 20° Obliquity. 6 D.P. Bevel Wheel. 20 " 20° " 6 D.P. PETROL PUMP. Pump driven by Cam on Distributor Drive Shaft which is driven by Spiral Gear on one end meshing with a spiral gear on Dynamo Drive Shaft. See SS.{S. Smith}221. Gear on:- Distributor Shaft. 25 Teeth. 5/8" wide. 20°Obliquity. 31°42'Helix.16.755 D.P. Dynamo Drive Shaft. 11 " 5/8" " 20° " 58°18' " 16.755 D.P. | ||