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 mileage testing and condition of high and low tension cables and ignition coils.
| Identifier | ExFiles\Box 97\5\ scan0189 | |
| Date | 11th May 1939 | |
| -4- High Tension Cable. This cable has completed 31,800 miles and was found to be in very good condition. There is no sign of any cracking of the Neoprene covering. The conductors were found to be in perfect condition. This is the best cable we have ever tried. Low Tension Cable. - Lucas harness. This harness has completed 50,300 miles and was found to be in a fair condition. The rubber sleeves covering the spring connectors has perished and cracked. Some of the single core wire has frayed badly at a point where they leave the harness. This type of harness in which the cables are enclosed in loom, has now been dropped in favour of loose cables enclosed in flexible metal conduit. We find that owing to the instability of design the former type is not worth while as any slight change in the wiring layout necessitates new harness, whereas, the latter type, lends itself more readily to alterations, and at the same time provide a reliable job at a relatively low cost. S.B.V. is to be brought up-to-date in this respect. Ignition Coil. E.75673 R.E. Coil No.31 completed 31,800 miles without trouble, and on examination was found to be quite up to standard. Coil No.32. was only carried as a spare, but on examination was found to be faulty. Investigation proved the end of the primary winding to be fractured at the point where it leaves the winding. The cause of this was vibration between the primary and secondary formers. The possibility of this trouble occurring on production has already been greatly reduced by the use of packing washers. We still feel, however, that further steps should be taken. We are now testing out a coil which has been sealed at either end with Ellisons Compound, and as this | ||