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 design, comparing it to the Bentley type, and experiments with split aluminium pistons.
| Identifier | ExFiles\Box 35\2\ scan 177 | |
| Date | 29th December 1919 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Bn.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EP.{G. Eric Platford - Chief Quality Engineer} X 2448. Hs{Lord Ernest Hives - Chair}5/LG29.12.19. X.2748. - RE PISTONS. X.3754. X.3732. -------------------------------------- X 3714 The proportions of our piston and connecting rod do not lend themselves to the Bently type of spring piston: the gudgeon pin boss being so low down, there is no room to get the flexible band in the bottom of the piston like what is used on the Bently pistons. It would be no use extending the skirt of the piston to get this flexible band on because our piston already extends out at the bottom of the cylinder when the piston is at the bottom of the stroke. I spoke to Capt. Bently about this piston recently in London and he said that our proportions would make it difficult to obtain the best results. We are sending a drawing of a standard piston to see what they can recommend. We have found it is possible to re-set the split aluminium pistons when the clearances have increased. This we have done by peaning them with a hammer on the non-pressure side. We are running a car with pistons treated in this way and so far it has run 150 miles quite satisfactorily. We are about to try a set of condemned solid type pistons. We shall split them and then pean them out with a hammer to give them the desired clearance. We have got some castings of the improved type split pistons on which the metal is better distributed on the Contd, | ||