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).
Energy diagram for a 40-50 HP engine with a 3.9 compression ratio, plotting energy percentage against R.P.M.
| Identifier | ExFiles\Box 69\4\ scan0360 | |
| Date | 19th October 1927 guessed | |
| ENERGY DIAGM OF THE 40-50 RR. COMP RATIO 3.9 SEE SHEET 2. % OF THE INITIAL PETROL ENERGY. R.P.M. LOSSES THRU :- COOLING WATER EXH. GASES RADIATION CHARGING WK. INDICATED TH. EFFCY. PISTON POWER MOTOR FRICTION TH. EFFICIENCY | ||