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).
Comparison of the Wraith III Stromberg carburetter against a standard version, detailing ten differences.
Identifier | ExFiles\Box 7\4\ X 608 Carburetter-page42 | |
Date | 26th October 1938 | |
Da.{Bernard Day - Chassis Design} Da{Bernard Day - Chassis Design}/Mc.S.21/G.26.10.38. WRAITH 111 - STROMBERG CARBURETTER. With reference to the recommendations made in Rm{William Robotham - Chief Engineer}/4/R.4.10.38. and Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}6/R.6.10.38. re the bringing of the Wraith 111 carburetters nearer to the standard Stromberg carburetter with a view to reducing the price, we are asked to pay for them. We give below a list of differences existing between our present Wraith 111 carburetter and a standard Stromberg carburetter with reasons for the differences.- (1). Throttle and Choke Levers to suit R.R. Controls. (2). Hexagon headed screws for throttle body joint, for main jet cap, and for float spindle. We have had experience in each of these cases of the parts being insufficiently tightened by screw driver in the Stromberg standard cheese heads and becoming loose in service. (3). Nut at operating end of throttle spindle to retain lever instead of riveting owing to poor job of riveting on earlier carburetters. (4). Improved fast idle connecting link to give increased bearing life and more definite fixing. (5). Fast idle cam with better finish and hardened face. (6). Improved bearing for choke operating lever to give longer life to lever and maintain fast idle setting. (7). Collar and split pin instead of washer and split pin for controlling end movement of choke spindle to give increased reliability. (8). Aluminium joint washer for main jet cap instead of fibre, as fibre washers are not used by R.R. (9). Stainless steel accelerator pump rod instead of mild steel to prevent corrosion and sticking, which has been experienced in service. (10). Stronger choke valve with increased diameter spindle, spring loaded in closed position, with reversed release valve, and bearings counterbored, all to remove risk of seizure of choke as experienced through the various causes in service. | ||