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).
Comparison of engine cylinder bore wear statistics for various vehicles and components.
| Identifier | ExFiles\Box 86\1\ scan0244 | |
| Date | 31th May 1937 guessed | |
| BORE WEAR. ENGLAND. CHEVROLET (16,500 miles in England) Brinell - 199/229. Wear assuming cylinders were originally to nominal size of 3.3125 = .000279 Wear assuming dimension at bottom of block to be same as machined = .000218 STANDARD R.R. BENTLEY CYL. BLOCKS. Average wear of Bentley cylinders in customers' hands taken over a great number of cylinder blocks. With aerolite pistons............. = .0003 Re-bore at .008 wear or 27,000 miles. With R.R. split skirt pistons ... = .00023 Re-bore at .008 or 35,000 miles. ------------------- FRANCE. 35-EX (15,000 miles in France) R.R. Liners ................... = .000113 Sheepbridge liners - Brinell 360 = .0001007 Sheepbridge liner drawing calls for 400 Brinell. 6.B.IV. (B.4 Unit) 16,000 Miles in France. R.R. Cast Cylinders. Wear .................... = .0001845 Brinell - 244/271. | ||