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).
Experiments with a low depression carburetter on the Phantom engine to improve volumetric efficiency.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 80 | |
| Date | 11th 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 RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LG3.11.27. PHANTOM CARBURETTERS - LOW DEPRESSION X8080 EXPERIMENTS. We have carried out some experiments on the Phantom with a single low depression carburetter with the object of finding the dimensions of the choke and pipe which would give a manifold depression of about one inch of mercury at a speed of 3000 r.p.m. and so improve the volumetric efficiency at these higher speeds. The induction manifold used was adapted from the std. Phantom manifold by altering the angle of the centre flange to which the uptake pipe was bolted - as shewn in this sketch. A 2" dia. down pipe and throttle was used. The carburetter had a choke of 1.6" dia. and in the centre of this was used a Claudel diffuser of .700 dia. The sketch below shews the arrangement of the carburetter. The free area past the diffuser in the choke was 1.625 sq.ins. or 51.8% of the throttle bore area. At 3000 r.p.m. full throttle the depression in the uptake pipe was 2.3 ins. mercury - the power output was 110.8 B.HP. or 62.5 lbs/sq.in. B.M.E.P. contd :- [Sketch annotations] STD. MANIFOLD FLANGE FITTED AT DIFFERENT ANGLE. 4" 8" | ||