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).
Performance of flexible ignition contacts, condenser sizing, and experiments with double breaker distributors.
| Identifier | ExFiles\Box 61b\1\ scan0153 | |
| Date | 6th June 1932 | |
| X6178 R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to R.{Sir Henry Royce} Hs{Lord Ernest Hives - Chair}/Wst.11/M.A. 6. 6. 32. IGNITION CONTACTS R.1/M.A. 6. 32. We still have the special flexible contact feature on our battery ignition distributors but we find owing to the amount of flexibility being apparently so critical, a slight difference between distributors in the way the formation of a pip on the contact surface occurs. In any case the worse cases now are considerably much better in this respect than the best of our previous rigid type contacts. Messers. Lucas say that they have not found a flexible contact support such as ours to be reliable owing to the slight flexing causing breakages at the point where the contact screw support is bent at a maximum angle. We must say that we have found the opposite, as our present design has not given any trouble in this respect. Apparently it is again a question of the amount of flexibility and we do seem to be right in this respect. The question of the size of the condenser is not only governed by the contact points but also by the voltage output of the coil. Too large a condenser causes too much loss of energy at break whilst too small a condenser causes excessive contact sparking. Experiments have shewn that an optimum size of about .20 micro-farads. Experiments are now in progress with the double breaker distributor but we do not anticipate such a good contact surface with these points, as the design rather indicates a departure from our flexible idea in order to make our points interchangeable with Delco-Remy. Hs{Lord Ernest Hives - Chair}/Wst. | ||