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).
Test report on piston efficiency compared to standard cup leather, with an accompanying mechanical diagram.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan107 | |
| Date | 15th February 1926 guessed | |
| contd :- -2- Our initial tests were therefore made with the object of discovering whether another type of piston would produce a better efficiency than the present standard cup leather. Our tests of efficiency were carried out at 1000 r.p.m. with an oil pressure of 13¼ lbs/sq.in. and a temperature of 60°C. We consider that this is quite an average running condition. After a burst of speed, the oil temperature will rise and we have found many reach 90°C. Under these conditions the efficiency of the piston may be expected to fall some 25% from figures we have obtained. Therefore the actual power available from each type of piston under extreme conditions will be about 25% less than the figure given in our comparative tests. contd :- | ||