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 failure on a Bentley, attributing it to insufficient clearance and proposing a gasket change as a solution.
| Identifier | ExFiles\Box 82\1\ scan0048 | |
| Date | 20th March 1933 | |
| X4853a G.W.Hancock, c/o Hotel de France, Chateauroux, Indre, FRANCE. To GWH.{George W. Hancock - Head Chateauroux} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}11/KT. 20.3.33. Considering the piston failure which occurred on the Bentley we have been wondering whether the piston hit the cylinder head. With the metal gasket there is only about .012" clearance between the piston and the face of the cylinder head. The limits of the piston may very possibly permit it to occasionally strike the cylinder head; in the case of these new pistons we may have got wrong with the dimensions to this extent. Additionally the metal gasket may have compressed still further which would accentuate the trouble. The solution is to run with the C & A gasket which you will find under the back seat of the car. We think that,in any case, it would be safer to run with this gasket on future occasions. By examining the other pistons you may be able to find out whether it has happened in any of the other cylinders. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||