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).
Test report and specification for Stromberg carburetter D.B.42.
| Identifier | ExFiles\Box 102\1\ scan0375 | |
| Date | 16th November 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to HS{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation} 4508 Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe} S/KW.16.11.35. 18-C-IV. Latest type Stromberg carburetter D.B.42 with fast idle and automatic choke unit built in casting. Carburation O.K. throughout range with the exception of very slight weakness at part throttle 30-45 M.P.H. Average consumption of two runs to Buxton and return is 16.2 M.P.G. at an average speed of 45 M.P.H. Max. average speed recorded on both runs 79 M.P.H. (speedometer reading). Max. speed recorded on Six Hills 81/2 M.P.H. Axle ratio 11 x 50; Tyres 6" x 19". Specification D.B.42. Choke 1.25". Main metering Jet .060". By-pass jet .048". Main discharge jet L.885 but with a 58 idle feed hole. Main discharge jet bore 36. Air bleed 70. Idle tube 64. Idle discharge top 64. Bottom 70. Pump jet 70. Needle valve seat .130. Thermostat setting 16. Vacuum piston stop .250" up and plugged. Hs{Lord Ernest Hives - Chair}/G.H.Ratcliffe. | ||