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).
Carburettor tests and methods for maintaining power at high rotative speeds for the Sports Phantom.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 165 | |
| Date | 24th November 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LG24.11.27. SPORTS PHANTOM - MAINTAINING POWER AT HIGH ROTATIVE SPEED. X8771 When analysing some of the results of low depression carburetter tests made on the Phantom engine we observed that although considerable gain in power was effected over the whole speed range when working with a low induction pipe depression, the peak of the power curve was not moved appreciably to a higher speed. We have therefore looked into some of the factors which were successful on the 20 HP. in both increasing the power over the whole range and raising the power peak to a higher speed - approx. 650 r.p.m. higher - with the object of repeating this on the sports Phantom. The advantages we should expect to gain from an engine with such characteristics would be in permitting the use of a moderately low axle ratio giving increased liveliness over most used speed performance without having to employ a high gear ratio with its consequent disadvantages at low speeds. Print No.1 shews the advantage gained when working at a low induction manifold depression and print No.2, shews the estimated percentage increase in power for various induction pipe depressions relative to the standard induction pipe depression of 3.9 ins.Hg. at 2750 r.p.m. This is calculated on the basis that the indicated power is proportional to the absolute manifold pressure. contd :- | ||