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).
Advantages of reversing polarity to a positive earth system on R.R. and Bentley cars.
| Identifier | ExFiles\Box 58\4\ Scan299 | |
| Date | 19th August 1936 | |
| Y6021. E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Wst.5/MA.19.8.36. REVERSAL OF POLARITY ON R.R. AND BENTLEY CARS. There are definite advantages in earthing the positive pole of the battery instead of the negative. These can be summed up as follows :- (1) Reduction in top corrosion of the battery due to elimination of any leakage current flowing from the positive pole to earth. (2) Reduction in spark plug voltage due to the fact that with the hot central H.T. electrode, negative ionization occurs more rapidly. This also evens up the voltage of each plug and is claimed to prevent elusive misfiring. (3) Reduction in wear of distributor H.T. rotor blade and erosion of sparking plug points. Many American and English cars are now "positive earthed" and we would like to alter all our Experimental cars in this manner. This requires a scheme issuing to alter the insulation of the dynamo brushes, reverse the field connection, alter regulator and cutout connections and modify the battery cable connections. Hs{Lord Ernest Hives - Chair}/Wst. | ||