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).
Experiment to improve rocker shaft lubrication by drilling holes, comparing Bentley and 20/25 HP methods.
| Identifier | ExFiles\Box 88\4\ scan0044 | |
| Date | 20th February 1934 | |
| -2- HS{Lord Ernest Hives - Chair}/Mths.{Reg Matthews}S/RW.20.2.34. To verify the fact that the quick supply of oil on the 20/25 H.P. is due to these holes being drilled into this annular groove, we drilled a standard Bentley rocker shaft in a similar manner, but instead of drilling two holes, we drilled only one to each rocker. Since the feed to the rockers is central on the Bentley we drilled the holes as follows :- The Rockers to Nos. 1 & 6 cylinders had .062 holes " " " 2 & 5 " " .046 " " " " 3 & 4 " " .039 " This arrangement we found to be quite satisfactory (oil being supplied to the push rods in less than one minute) so that to overcome the trouble the rocker shaft can be drilled as above or similar to 20/25. In the latter case, however, the order of the holes will have to be reversed from the standard 20/25 design, owing to the feed being in a different position. We think the method we used in drilling the rocker shaft is better than standard 20/25, since it allows adequate lubrication to the bushes as well as push rods. There is only one bush lubricated on the 20/25 rocker, but the method we used allows an oil hole to supply each bush and one hole to supply the push rods. A standardisation sheet is being issued. HS{Lord Ernest Hives - Chair}/H.Matthews. | ||