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).
Recommendations for dealing with Bentley engines at service depots, detailing modifications for oil consumption and engine roughness.
| Identifier | ExFiles\Box 114\3\ scan0087 | |
| Date | 1st June 1938 guessed | |
| BY.{R.W. Bailey - Chief Engineer} COPY. RECOMMENDATIONS FOR DEALING WITH BENTLEY ENGINES AT SERVICE DEPOTS. Where not already done all 4 1/4 litre engines should have large capacity oil pumps fitted, and in order to avoid complaints of high oil consumption. High Pressure scraper rings EB.3122 should be fitted and oil holes in connecting rods should be plugged up. This change is known as Modification 'A'. The most expeditious and economical way of dealing with this modification is to remove cylinder head and block, thus giving access to pistons and connecting rods, and avoiding disturbing the bearings, by this method the car should only be needed for 7 hours. In the event of a complaint of engine roughness and thumps, high oil consumption or low oil pressure either as an owner's complaint, or as indicated by a special test for this feature on an incoming car. The condition of the bearings may be determined by an oil flow test. From the result of this test a decision can be made as to whether a B. or C. modification should be done. See table of flow test. The mileage of the car and type of owner should be factors for consideration in making this decision. At the best Mod.B can only be considered as a temporary expedient and will ultimately have to be followed by Mod.C. which means a double expense. There have been a number of cases of dissatisfied owners owing to a recurrence of trouble after Mod.B has been done. There have been no failures after a Mod.C has been carried out in conjunction with the latest recommendation with regard to the amount of "nip" of bearings. This statement is based on a year's experience and it is considered that cars so treated will last out the period of guarantee. cont'd.{John DeLooze - Company Secretary} | ||