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).
Necessity of adding oil to petrol for supercharger lubrication on the 'Bensport' model.
| Identifier | ExFiles\Box 140\1\ scan0028 | |
| Date | 6th October 1932 | |
| X 209.. To Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} E.2/HP.6.10.32. c. Wer. Hs.{Lord Ernest Hives - Chair} re Bensport. In reply to Sg.{Arthur F. Sidgreaves - MD}18/E.5.10.32, this question of oil in the petrol is a very nebulous one, and the blower is such an unknown quantity at the present time for general use that there is no established practice. At one time we understood that it was necessary to use oil with the petrol for the Rootes blower, but recently our information is that this is not essential. With a Rootes blower mounted direct on the front of the crankcase as we propose, it is likely that the gears and bearings can be lubricated as part of the engine in the usual way. Bugatti is compelled to have a separate system of oil supply as his blower is mounted on the side of the engine and driven externally. The Powerplus blower has its own oil pump which meters oil to the surfaces requiring lubrication, but oil is generally added to the fuel as a measure of precaution, and it is argued that a highly supercharged engine requires this oil for upper cylinder lubrication. We do not accept this latter view, and fully agree that the oil in the petrol must be avoided if at all possible. It is mainly for this reason that we are now pushing on with an alternative design of Rootes blower for the Bensport, which can be interchanged with the Powerplus. In the recent 500 miles race at Brooklands we understand that no oil was used in the petrol for the Powerplus on the winning M.G. and that the blower finished in good condition. E.{Mr Elliott - Chief Engineer} | ||