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 Bentley 60 valve guide inserts, detailing interference fit tests and their results.
| Identifier | ExFiles\Box 123\5\ scan0118 | |
| Date | 13th October 1938 | |
| 10H4 To Ey. from HPS{Horace Percy Smith - Experimental Factory Mgr}/W.Bell. c. to Rm.{William Robotham - Chief Engineer} c. to Dr. HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}4/CB.13.10.38. BENTLEY 60 VALVE GUIDE INSERT TESTS. EB.4034. These parallel type valve guides were pressed into a scrap section of the cylinder block, EB.3778, interferences being tried between zero and .0015". A screw clamp was used, and the size/size guide went home a little too easily. Using a guide giving an interference of .0015", the pressure required was considerable, but on examination, the bore of the guide was found to be correct size, no collapse having taken place. No cracks were revealed when the cylinder block was chalk tested. An interference of .0010" with a tolerance of +.0005" to -.0005" can therefore be regarded as satisfactory. No. 1 B.60 engine unit was fitted with valve guides having diametral interferences varying from .0005" to .0015" (a chart of their positions in the cylinder block being illustrated in BL.2213 attached) so that their behaviour under engine conditions could be observed. R.M.L. HPS{Horace Percy Smith - Experimental Factory Mgr}/W. Bell. | ||