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 trouble, brake wear, and engine modifications on a Bentley car.
| Identifier | ExFiles\Box 82\1\ scan0110 | |
| Date | 11th April 1933 | |
| X45513a. To Hs.{Lord Ernest Hives - Chair} from Sg.{Arthur F. Sidgreaves - MD} Copy to Wor{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} re Bentley Car. Sg{Arthur F. Sidgreaves - MD}5/E11.4.33 I am sorry to see from the report dated the 7th that there has been further trouble with pistons. Apart from the breakage of the skirt of one piston I gather that there is again a tendency for the split rings to be causing what is known as worm-eating. If such is the case, would it not be better to go over to the other type, i.e. the aluminium plug which I understand we have used in the past with success. Re Brakes, I notice that this report and several others have referred to the brakes wearing out too rapidly. I should be glad to know what you have in mind to overcome this and whether it is partly due to the increase in percentage of front wheel braking. In a report dated 3.4.33 reference is made to maximum speed being only 88 m.p.h. because of having to use a copper asbestos gasket. The position about this is not quite clear to me because I understood that the pistons in use were standard 25 HP. pistons which make a 30. thou. greater clearance than the pistons previously running, and also it has been stated that the combustion chamber was being altered in order to keep the compression up to what was previously intended. Probably this modification may have referred to future engines, but I still do not understand why the thicker gasket was necessary in view of the pistons in use being smaller in dimension. Sg.{Arthur F. Sidgreaves - MD} | ||