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 and standardisation of a new 'Glowray' wire ignition ballast resistance to improve ignition performance and contact point life.
| Identifier | ExFiles\Box 168a\5\ img070 | |
| Date | 28th May 1937 | |
| To E.{Mr Elliott - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Wst. c. Hs.{Lord Ernest Hives - Chair} c. By.{R.W. Bailey - Chief Engineer} c. RHC.{R. H. Coverley - Production Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} 6145. Rm{William Robotham - Chief Engineer}/Wst.15/AP.28.5.37 IGNITION BALLAST RESISTANCES. We have completed tests on chassis using an ignition ballast resistance wound with "Glowray" wire instead of pure nickel. The reason for this change is that we are anxious to obtain a non-temperature coefficient ballast resistance, as with our standard ballast when switching on 'cold' the contact points on the distributor have to deal with an excessively large current momentarily and this causes excessive wear of the contact breaker points. Furthermore, after the engine has been run hot at fairly high speeds, slowed down and then immediately accelerated with the ballast hot the reduction in the current on the ignition system due to the rise on resistance in the ballast when hot is liable to cause misfires. We have fitted this ballast to most of our experimental cars and our conclusion is that the performance of the ignition system is better and the contact point life improved. For instance, a pair of these ballasts were fitted to Y-EX. and completed 21,000 miles running, during which time the ignition contacts in the distributor were not adjusted or cleaned in any way, which is we believe a record for the P.J. engine. We are therefore issuing a Standardisation short immediately for this item. Rm{William Robotham - Chief Engineer}/Wst. | ||