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).
Water leak issues at the water pump bend on the Bentley & 25/30, proposing design improvements.
| Identifier | ExFiles\Box 149a\1\ scan0088 | |
| Date | 13th April 1937 | |
| 1269. To Da.{Bernard Day - Chassis Design}from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/AP.13.4.37 BENTLEY & 25/30. WATER PUMP BEND. In the list of quarterley complaints a large number of water leaks are reported at the point where the water pump bend connects to the cylinder block. The stud bosses in the cylinder block at this point have been found in some cases to be broken or cracked. Investigation by production shews that if the studs do not have good fitting threads, it is possible to burst through the bosses, resulting in leaks when in service or on test. Their recommendation is to fit studs having tighter threads, strengthen the bosses and spread the stud centres. Another point is the fact that the "Dermatine" jointing material tends to collapse when in service and cause leaks and here again there is a possibility of cracking the bosses in endeavouring to cure by tightening. We have found that "Klingerite" as a water joint is quite satisfactory, more durable and less liable to collapse in comparison with "Dermatine". Together with Production's recommendations the inclusion of 'Klingerite' for the joint would undoubtedly overcome this trouble in the future. The present arrangement, however, of having to make a joint on a vertical and a horizontal face as per the water pump bend could be improved by adaption of the Phantom III. design which is proving very satisfactory. This is shown on the attached sketch Rm.{William Robotham - Chief Engineer}354 as adapted for Bentley and 25/30, and to complete the job requires a dowel to locate the pump against its tendency to rotate. There is one doubtful point about this suggestion that is, when the circulating water is drained from the engine the cylinder block is not completely drained. We do not consider this to be an important point, however, as the danger due to freezing in the block is only present if the cylinder block is full of ice. We are endeavouring to run this on our next 15,000 miles test unless the design can offer any improved or alternative suggestions for this scheme. Can this be incorporated on Wraith. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||