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).
Instructions for adjusting a 30 HP Stromberg Carburetter to address weakness at part throttle.
| Identifier | ExFiles\Box 122\2\ scan0072 | |
| Date | 26th September 1936 | |
| To Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c. to Mx.{John H Maddocks - Chief Proving Officer} c. to Mr. Fisher. (Zenith Co.) 30 HP Stromberg Carburetter. Further tests have been carried out on 21-G-IV relative to the complaint of weakness at part throttle between 40 and 50 M.P.H. It is essential that the following is checked and adhered to before changing the main metering jet. (1) Byepass jet adjusted to open at 5/16" throttle openings i.e. .312" dia. bar placed central between bore and butterfly. (2) No lag allowed between accelerator piston at end of stroke and byepass jet opening. In odd cases it has been found necessary to increase the piston stroke slightly. This is achieved by turning the circular nut clockwise half to one full turn, and re-drilling for the split pin, care being taken that the piston rod does not foul the floatchamber cover in the closed position after assembly. Hs{Lord Ernest Hives - Chair}/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Ratcliffe. | ||