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 a Bijur starter motor, comparing battery performance, and detailing the improvements of a new model.
| Identifier | ExFiles\Box 23\2\ Scan078 | |
| Date | 18th May 1921 | |
| X1086 CC Mr. Nadin. Mr. Bagnall. Mr. Hulley. Mr. Southern. Mr. Caswell. OY1-G 18621 May 18th 1921. To Mr. Hives: From Mr. Olley. X.4031. X.3560 X.1402. X.294. X.3231. X.1086 X.2082. X.1088 - ME BIJUR STARTER MOTOR & GENERATOR. Replying to yours of April 29th, (Hs{Lord Ernest Hives - Chair}1/LG29.4.21): With regard to the experience with Bijur motor on 22-LW, we find from Mr. Allison and Mr. Hulley that the water pump was found to be frozen on the engine, which may have had a good deal to do with making it difficult to start. Mr. Allison, however, does not remember that the voltage had dropped to such an extent that the battery ignition was inoperative; in fact, he says that the motor was started and that it was then found that the water pump had seized. However this may be, you will see from the enclosed curves that the new Bijur motor, of which samples will be delivered in the next few days, has very nearly the same torque curve plotted against current as the H-R motor and has a very much higher speed curve. It is undoubtedly a very great improvement over the original Bijur motor. X.1198.X.4206. It has to be considered also that we are expecting to adopt the 90 ampere hour Willard battery in place of the 67 ampere hour Exide. The discharge curves of these batteries, taken from tests in our own shop, show that at 400 amperes the Will-rd will give 8.4 volts as against the Exide 6.8 at temperatures of about 70ºF and at low temperatures of say 10ºF.{Mr Friese}, the difference in internal resistance of the two batteries is very much greater than this. You will remember that substituting the Willard 90 ampere hour battery for the Exide made all the difference in the world in starting 4-EX with the old Westinghouse motor which took such a lot of current. From these considerations you will see that we should be making a considerable stride in using the new Bijur motor. | ||