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).
Throttle sticking for a GUB-5 Stromberg Carburetter DB.42.
| Identifier | ExFiles\Box 107\1\ scan0356 | |
| Date | 31th January 1936 | |
| x560 To Rm.{William Robotham - Chief Engineer} He/GR.{George Ratcliffe}2/JH.31.1.36. GUB-5 Stromberg Carburetter DB.{Donald Bastow - Suspensions}42. Report on throttle sticking. This carburetter had a collection of minor faults all relative to the throttle sticking indirectly and although this is an experimental model, exactly the same applies to the DA.{Bernard Day - Chassis Design}42. (1) Pump link L.722 should be fitted to inner hole (summer setting) of pump L.761, (.450" c/s). This prevents side thrust on the pump rod L.821 when the throttle is closing. (2) Pump rod assembly L.821 to be examined as follows:- (a) Top link should be at right angles to pump rod in both planes. (b) Top link hole should be concentric and clear of the piston rod. (c) Split pin of piston rod to be clear of float chamber cover. (d) Pump spring to be square at both ends. (e) Pump piston to be free in cylinder bore. The throttle controls were eventually set up to the following figures:- E.76537 spring was fitted to throttle lever at a radius of .825". Load checked at spring anchorage on lever; start to open at 3½ lbs. Initial length of spring when assembled 3.75". Accelerator pedal loads at start 5 to 6 lbs, and full open at 9 to 10 lbs. These figures were found to be the minimum required for satisfactory operation. Slight detonations were audible to this car at 55/60 M.P.H. with water temperature at 80°C. | ||