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).
Issues with an M.L. Magneto causing engine pre-ignition and running backwards on certain car models.
| Identifier | Morton\M11\ img077 | |
| Date | 4th November 1917 | |
| For 7CA & 4A CB ORIGINAL By from R.{Sir Henry Royce} (Struck through) C. to EH. (Struck through) C. to NP. (Struck through) C. to DJ. (Struck through) C. to Mr. Watson. R1/W4.11.17. 3 Re - M.{Mr Moon / Mr Moore} L. Magneto. X. 3209. We have great respect for Mr. Watson's work in this direction and shall be glad, in view of the possibilities of "After-the-War-Chassis" work, to have two or three magnetos suitable for our cars. Mr. Hives will attach one to 49-GB and one for 7-CA. I would like Mr. Watson to tell us whether it is possible for a magneto with a suitable length of cam to pre-ignite an engine and run it backwards in the way we have experienced lately on 7-CA. In this case the magneto was slightly advancedbefore the dead centre, but on retarding it to nearly the dead centre = (standard position) we found the same thing to happen again. In this particular instance the engine was lubricated with very thin oil and bounced about rather vigorously after passing a compression. It was thought /when the magneto was running backwards/ /the spark occurred/ towards the corner of the cam where the make occurs and by breaking the low tension circuit by-running-against-the-cam (running-against-the-cam is struck through) a spark was given and as the exhaust system had not had a considerable amount of explosive mixture the engine ran backwards for several revolutions. It did exactly the same on the Remy ignition which was temporarily fitted. This particular car was one which was usually started with an electric starter but on the occasion mentioned the battery of the starter was run /down/ and an attempt was made to start the (Left Margin) X. 682 X. 2631 | ||