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 diagnostics, detailing oil pressure, oil consumption issues, and component inspections following a test run.
| Identifier | ExFiles\Box 131\2\ scan0240 | |
| Date | 22th July 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}1Q/N.22.7.38 Cont'd ------------------------------------------------------ Idling, nothing showing on the gauge approx: 1000 revs. 3 1/2 lbs. pressure. 2000 " 4 1/2 " 3000 " and upwards 5 1/2 lbs pressure. The oil escaping from the rocker bearing was approximately 1 drop per minute. There was only a weep of oil coming out of the end of the rockers. At the end of ten minutes slow running there was a slight cloud of smoke upon opening up. We examined the plugs and found them to be still wet with oil but reduced about 25%. This led us to doubt the pistons, but before definately condeming them, a further high speed run of 100 miles was carried out, then 30 miles of traffic at slow speeds. Examination of the plugs was exactly the same as previously. This led us to dismantle the cylinder heads and pistons with the idea of fitting 'L' shaped rings. Examination of the pistons prior to taking them out, gave a doubtful issue. They were carboned up approximately 1/16" thick with wet carbon, but no oil had drained to the lower part of the piston heads. Upon taking the pistons out of the bores, there was not sufficient evidence to warrant that the plugs were becoming oiled up from oil passing the pistons. The condition was such that a tester would state, on wet side only. We therefore did not attempt to fit the 'L' shaped rings. The inlet valves when taken out were smothered with oil and carbon as also was the inside of the valve port. This was almost conclusive that the trouble was due to top over-oiling. Measurements taken of the valve guides and valve stems did not show any definate wear, they were as far as it is possible to state .001% clearance. Continued.... | ||