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).
Comparing oil consumption and leakage with seven versus three oil feeds for main bearings on Phantom and Silver Ghost cars.
| Identifier | ExFiles\Box 72\1\ scan0114 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 21. 12-6-25) J.H.D. EXPERIMENTAL REPORT. -3- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/ACL/LG151225 Furthermore the results we have obtained from two cars on test, a Phantom and a Silver Ghost, show that with the same arrangement of oil feeds, i.e. direct supply to the three main bearings only, and with the pressures adjusted to give the same oil leakage past the bearings, the consumptions are approx. the same. Test bench results also support this statement. Plain concentric pistons were used for these tests. It has been shewn in a previous report that bearings which allow a liberal oil leak when having the standard arrgt. of seven oil feeds definitely give less leakage when the xxxxx direct oil feeds are reduced to three. We further found that where the leakage was initially small, no advantage was obtained by using three feeds, as might be expected. Admitting that in the latter case we should gain no advantage in reverting to the Silver Ghost practice of bearing feeds, we think that the average results from such a change would show an improvement and the effect of wear with regard to over-oiling would not be so marked as when using seven direct feeds. It should be mentioned that for the purpose of the comparative tests made between seven and three feeds, the intermediate bearings for the latter test remained unaltered i.e., they still retained the oil grooves which were used when these bearings were direct fed with oil. With three main feeds only the grooves in the intermediates would be unnecessary and as we have shewn by the a test, better results could be obtained XXXX without them. contd :- | ||