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).
Adjustments to the throttle return spring and the torsional return spring on the choke.
| Identifier | ExFiles\Box 20\9\ Scan121 | |
| Date | 24th February 1936 | |
| -2- (3) The throttle return spring as arranged has a returning load in the closed position of 3 lbs. at the throttle control connection radius. This was not sufficient however to return the throttle to the stop and it was necessary to increase the loading to 3 1/2 lbs. to overcome any sticking and obtained by substituting a .800" link in place of the existing 1.00". The actuation of the accelerator pump in being so stiff necessitates this 3 1/2 lbs., for in a standard Stromberg the original arrangement of 3 lbs. load is sufficient to return the throttle when the engine is running. (4) The torsional return spring on the choke throttle is too strong so that on starting cold, the movement of the choke is negligible and the engine stops through over-richness. By reducing the initial twist on the torsion spring by 30° the spring tension is just sufficient to close the choke. In this condition with a cold start, the automatic opening of the choke is just sufficient to keep the engine running without overloading, although the suction on it just moves it the existing range of the stops. The two torsion springs foul each other when the choke is in the closed position. Other than what is deemed necessary from this report, the modifications as requested in E/sn.{Mr Sanderson}3/MW.20.2.36, and E.10/HP.20.2.36 should be carried out. The next step following these modifications is a trial in a chassis for vapour lock, starting, and opening up. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||