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 on fuel types, petrol supply, and carburetter adjustments for engine tuning.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan193 | |
| Date | 29th January 1925 guessed | |
| contd :- -8- trouble - as well as others likely to occur through the use of a poor grade petrol - only good grades should be employed. With regard to the use of special fuels, if desired a 50/50 mixture of good petrol and benzol can be used and should not necessitate any alteration to the mechanical adjustment of the carburetter. The petrol supply should be adequate for the demand of the engine i.e., not less than 85 pts/hr. should pass through the p two plug holes beneath the high and low speed jets with a 15" petrol head. If this flow is not obtained the collar on float chamber needle valve should be suspected because if this has been raised from its correct position on the shoulder of the needle valve - in order to alter the petrol level - the lift of the needle valve will be restricted when the float is at its lowest position and result in a reduction of the maximum petrol flow through the carburetter. As air and fuel temperature have considerable influence upon carburation, it cannot be too strongly emphasised that adjustment should not be made until the engine has attained its normal working temperature and the jacket water at approx. 80°C. SETTING LOW SPEED JET. With regard to the adjustment of the low speed jet some misunderstanding seems to exist as to the conditions under which it should be set. It is hoped that the following will clear this point. We can see that it is logical that the low contd :- | ||