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).
Technical memorandum detailing an investigation into throttle design differences, specifically the boss, and methods for correction.
| Identifier | ExFiles\Box 50\3\ Scan022 | |
| Date | 24th February 1921 | |
| H.R. 293A (100 T) (N.H. 798. 10-12-20) G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2947 Contd. -2- Hsl/LG24.2.21. ution. It was also found by them that the difference in the throttle was caused by a difference in the bosses which are formed on the inside of the throttle to carry the studs for bolting to the throttle to the carburetter. The difference is that on a good throttle there is a hanging boss - on a bad throttle the boss is made to form a bar. The drawing, we believe, has always shown this boss in the form of a bar but actually on pre-war throttles, the throttle was produced with a small hanging boss. Sometime after we started up on cars, new patterns for the throttles were made; these bosses were then made in the form of a bar. We have carried out a number of tests to confirm the alteration to the boss is the cause of the trouble. We have taken several throttles which have been good and built up the boss inside to form a bar with a mixture of soap; this has made the distribution bad. Immediately we removed the dummy boss, the distribution has been alright. We have taken the throttle which is bad and have milled away a section of the boss which is added and we have found by this means we have made a bad throttle into a good one. The operation of milling away the boss is, however, expensive as it means first of all, cutting out a section to get at the boss and them after the operation has been done, to put it back again. We have tried a number of schemes to try and correct a bad throttle. We found and proved that if we screw a piece of 3/8" rod in the throttle on the opposite side of the boss which is causing trouble, we can correct the faulty Contd. | ||