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).
Supercharging performance, indicator diagrams, and Mercedes engine construction.
| Identifier | ExFiles\Box 22\5\ Scan132 | |
| Date | 18th November 1924 | |
| R.R. 493A (20H) (D.A. 652 20-3-24) J.H.D. -3- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rml/LG18.11.24 EXPERIMENTAL REPORT. at each speed. Figures given for a run of two mins. indicate what would have happened if the test had been prolonged. The power obtained to drive the blower represents actual working conditions against pressures equivalent to those that are generated when supercharging. The noise produced by the blower is very marked and apparently emanates from the rapid cut-off of air by the rotors The maximum gain of 40% in B.HP. indicates the possibilities of supercharging if properly carried out. INDICATOR DIAGRAM. The main point of interest in this diagram is the relatively slow rate of burning when supercharging. It might be anticipated that increased turbulence due to forced induction would materially increase the rapidity of combustion. We should be inclined to say that placing the blower between the carburetter and induction pipe might prove more satisfactory in this direction. MERCEDES CONSTRUCTION. The Mercedes cyl. block is exceptionally light. It consists of steel cylinders forged and machined separately and welded together in pairs across the bottom flange. The valve guides and pinion for the overhead camshaft drive are located in a steel cradle which carries three transverse brackets to support the Camshaft. These brackets are welded to the cradle, as are also the sheet steel pressings for the water jacket. contd :- | ||