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).
Brief notes on engine component materials, finishes, and design to reduce wear and improve performance.
| Identifier | ExFiles\Box 142\1\ scan0148 | |
| Date | 8th June 1938 guessed | |
| 1204. Automotive Industries of Apl. 23rd Page 572 et seq. Brief notes on some "High Sights" Valves & guides Extremely fine finish of valve stems & guides result in greatly reduced wear. The smaller the initial clearance, the less the rate of wear. Copper plating stems .0002 thick, permits of finer initial clearance. Bonderizing surface of stems said to be beneficial, also applied to clutch facings (Cadillac) and suggested for piston rings. Guides nitrided to .008 to .010 deep, and honed, said to reduce wear of guide & stem by 6 to 10/1, the reduced wear being considered to offset the extra cost. Valve guides should not extend into the flame swept port above the water cooled part of the block. Piston & Cylinder All tests confirm that extra fine surface finish has marked effect on oil consumption & wear. Cast steel cylinder liners, hardened and honed by hydraulically controlled stones, eliminating grinding op. after hardening; said to bring cost to a commercial proposition. Tests did not indicate that the hardest possible liner (such as 900-1000 Brinell) is of necessity the most desirable. | ||