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).
Comparative wear on cylinder bores caused by aluminium versus cast iron pistons.
| Identifier | ExFiles\Box 35\2\ scan 221 | |
| Date | 12th April 1920 | |
| X.2748 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} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}1/LG12.4.20. X.2748. RE PISTONS. X.3732 During our last visit to W.W., Mr. Royce raised the question re. the wear on cylinder bores caused by aluminium pistons. He mentioned that Tylors the Engine makers had been forced to scrap a large quantity of aluminium pistons because they had caused excessive wear on the cylinder bores. We have measured two sets of cylinders which have run 10,000 miles with aluminium pistons, and find that the maximum amount of wear anywhere on the bore is .001". The amount of wear on the portion of the cylinder which is not traversed by the rings is nil. This small amount of wear compares very favourably with the amount we get when using cast iron pistons. On repair Cars fitted with cast iron pistons the average maximum amount of wear is .005" when the car comes in for overhaul which is generally after 20,000 miles running. On those cars it is always found that the wear takes place on the portion of the cylinder traversed by the rings. It is rather surprising the variation in the amount of wear on Repair car cylinders; in some cases the cars have run 40,000 miles with the maximum wear of .002" whereas in another case the car, after running 10,000 Contd. | ||