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).
Piston types and oil consumption, including correspondence about parts supply and modifications.
| Identifier | ExFiles\Box 114\3\ scan0188 | |
| Date | 21th September 1937 | |
| -2- " The scraper rings should be of the latest type EB.3122, high pressure 32.0 lbs.sq.in. We should like to know your result with these pistons since this combination of piston and rings has given such good results in France". ---------- Upon my next visit to Derby, I took the matter up with By, stating that the records would be in a mess twelve months hence, if we continued to use the new type piston, as with these pistons the con rod lubricating hole must not be stopped up, or we should be in trouble. By.{R.W. Bailey - Chief Engineer} agreed and gave me verbal instructions that, in the case of Kingsbury receiving the new type piston, the con rod holes should be left open, in the meantime the matter would be discussed. Nothing further happened until I again visited Derby, when I obtained a verbal ruling from By.{R.W. Bailey - Chief Engineer} that no new type pistons should be fitted and I gave Kingsbury that verbal ruling. On the 21st. of September I again wrote to By - RM{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}17/N.21.9.37, copy hereunder: " Bentley Pistons & Oil Consumption. "The question of the supply of pistons to Depots has again arisen. You will remember my conversation with you regarding the latest type piston being sent to the Depots when replacements are necessary. Kingsbury have had one batch of the old type, then the next batch are of the latest type; now the latest type piston seems to be standard. In dealing with the cars where the modified oil pump is fitted, the Kingsbury Depot have had to plug up the lubricating hole in the con rod, and in some cases fit the high compression scraper ring to obtain good oil consumption. The question arises that if the tight fitting skirt piston is fitted, the rods must not be stopped up. Is it possible to let Kingsbury know whether the supply of pistons from now onwards will have the tight fitting skirt or not, so that they will have some data to work on. We do not want to stop up the rod, if later a tight fitting skirt piston will be fitted" ---------- Continued..... | ||