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 leaks from the Bentley water pump connection to the cylinder block, with a suggested cause and remedy.
| Identifier | ExFiles\Box 130\2\ scan0029 | |
| Date | 6th July 1936 | |
| To Rm.{William Robotham - Chief Engineer} c. to Py. (crossed out) c. to E.{Mr Elliott - Chief Engineer} (crossed out) X1113 Kingsbury. 6th July, 1936. Bentley - Water Pump Connection to Cylinder Block. During the March quarter at Kingsbury there were 43 cases of water leaks, the majority being from No.2 plate, while I have seen three definite cases (16-CR{Mr Cra???ster / Mr Chichester}, 23-CW and 152-AH) on cars here to-day. The leaks in each case are slight, but leave rusty marks down the crankcase, to which on a clean engine exception is taken. In every case I have seen, the leak is on the face joint between the plate and the cylinder block below the water pump connection. Their method of dealing with this here is to lap in the plate and fit a paper washer. The addition of the paper washer lengthens the life of the joint but they have had recurrent cases after lapping in the plate. This points to the fact that there is a weakness in design and it is not due to bad fitting in the first place. I have also seen cases on R.R. 30-HP's at Cricklewood. Suggested Cause. It seems to me that after a period of time the rubber washer A.{Mr Adams} between the connecting pipe and the plate settles down and relieves the tension of the 1/4" studs, by which time the rubber washer is well stuck to the two faces and although not nipped tight is still water tight. This leaves the plate only nipped tight to the block by the four countersunk screws, which are situated all in the top half of the plate. This is borne out by the fact that the nuts BB (see attached sketch) are found not really tight. The expansion of the aluminium bracket supporting the bronze pump and connecting pipe is probably different and will cause slight movement. Proposed Remedy. To get over this trouble I suggest a hard washer be used in the place of the rubber washer A.{Mr Adams} to enable the nuts BB to be tightened and remain tight, so bringing the plate always up to the cylinder block at the bottom. Hs{Lord Ernest Hives - Chair}/J.B.Dixon. This has received the Design's attention and an alteration to the casting was made, but the fault is still there - G.W.Hancock. | ||