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).
Excessive oil consumption on the Bentley 4¼ litre chassis.
| Identifier | ExFiles\Box 146\3\ scan0105 | |
| Date | 15th October 1936 | |
| W/P - Sr/VA. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}8/KW.15.10.36. Excessive Oil Consumption on Bentley 4¼ litre Chassis. We have your note Sr/VA.1/ET.13.10.36. On all the 4¼ litre Bentley cars we have the extra oil hole drilled in the connecting rods. When the rings are in good condition this makes but little difference to the oil consumption. When wear takes place, however, blocking up the hole in the rod may improvemthe consumption by as much as 300 M.P.G. In the case of a badly worn cylinder block, the risk of seizure seems exceedingly remote, and we therefore recommend that you cut off the additional oil supply.from the connecting rod in cases where you do not wish to rebore. If at any time the engine is rebored and new pistons fitted, this hole should be opened out. We are interested to have your report on 'L' shaped rings fitted to worn bores. We are getting consumptions of 2,000 M.P.G. on the 25/30 now running in France: in this case one 'L' shaped ring was fitted but in new bores. We are dealing with your order for oversize pistons and 'L' shaped rings. HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||