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).
Engine cylinder and valve guide wear after a 10,000-mile test, comparing in-house and externally cast parts.
| Identifier | ExFiles\Box 76\4\ scan0234 | |
| Date | 28th June 1920 | |
| X 3315 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to By.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to Sft.{Mr Swift} Hsl/LG28.6.20. X.3433. RE 40/50 ENGINE CYLINDERS CAST AT R-R WORKS. X.3315. We have run 10,000 miles on a set of cylinders cast at our own Foundry. On measuring these up after this run we found that the maximum wear on the cylinder bore was .0005". This is equivalent to what we get on the cylinders which have been cast by outside firms. The chief wear we get on our cylinders is in the Valve Guides. In 10,000 miles the valve guides wear to the extent of .004" to .005" oval. We get this same amount of wear on the cylinders which have been cast outside. This wear takes place both on the inlet and exhaust valve and it does, to some extent, spoil the dead slow running of the engine. X.3315. We have tested some "Duco" Valve Lubricatoes; these consist of a circular wad of absorbant material which is slid over the valve stem. The idea then is to sturate this wad with lubricating oil. We found that these do undoubtedly assist to prevent wear in the valve guides but after a long run they become ragged and also owing to the fact that our valves are exposed they collect a lot of dust and dirt. We think however, that the wear on the valve guides is a thing that ought to be tackled. Hs.{Lord Ernest Hives - Chair} | ||