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).
The testing, repair and performance of a 260 HP Mercedes engine, including power curve data and spark plug analysis.
| Identifier | ExFiles\Box 34\2\ Scan092 | |
| Date | 10th December 1917 | |
| E.R. & S. (600 T) (S.D. 408. 26-4-17.) Bm. 2/158/13. *.2514 To R.{Sir Henry Royce} from EH. c. to BJ. c. to E.{Mr Elliott - Chief Engineer} c. to EY. EH1/LG10.12.17. 10th Dec. 1917. 3/11 X 2514 X.2295 260 HP MERCEDES ENGINE. X We had to take the crankshaft out of this engine and true up the taper end where it had been "galled" by the coupling. We have had it running again. Below is a power curve. REVS HP. B.M.P. ---- --- ------ 800 140.0 104.5 900 158.0 105 1000 175.0 104.5 1100 193.0 104 1200 212.0 105.5 1300 227.5 104.5 1400 244.0 104 1500 256.2 102 1600 269.3 100.5 1700 278.5 98 1800 280.1 93 We find that the sparking plug positions on this engine is not very good, it is very sensitive as regards the type of ignition plugs. It will be noticed that the ignition plugs are both on the induction side of the cylinder, about 60° from each other. Earlier engines of this type had the plugs at 180°. We find the engine will only run satisfactorily on "Bosch" long reach plugs as were fitted to the engine. If we fit K.L.G. F5, or Lodge plugs, the engine pops and miss-fires and will not run until we strengthen the mixture. We have tried with various lengths of spark gaps, it is better with .020" than with .010", we have also (CONTD) | ||