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 performance, including acceleration tests, oil temperature, and analysis of the cylinder head and valve components.
| Identifier | WestWitteringFiles\V\2January1931-April1931\ Scan002 | |
| Date | 30th January 1931 guessed | |
| -2- The tappet clearance had to be reset every two days. The cleanliness of the engine was not particularly good. Oil leaked from the rocker cover, draining down the cylinder walls. Oil also leaked from the annulus round the fan drive pulley due to the crankcase pressure being too high. We reported at 6,000 miles the views taken re the petrol and oil pipes. Acceleration tests taken were as follows :- Speed M.P.H. Time Secs. 10 - 20 .......... 4.50 20 - 30 .......... 5.50 30 - 40 .......... 6.70 40 - 50 .......... 8.25 50 - 60 .......... 18.00 Max. speed on level 65 M.P.H. 10 - 60 .......... 44.50 20 - 60 .......... 42.50 30 - 60 .......... 39.00 40 - 60 .......... 30.00 The average oil temperature taken at the pump supply was 54°. This was increased to 60° during the latter part of the mileage with the increase of the water temp. The engine was run throughout the test with 1.5 gallons of oil in the crankcase. CYLINDER HEAD to E.55298. Incorporating E.55805. The cylinder head does not show any fractures to have taken place. There has been no signs of any water leaks. The water tubes do not show any deterioration. The exhaust seats as previously reported have sunk into the head approx. .0875 This was reported to be due to the hammering effect, but two theories are advanced as the cause of the deterioration, one is erosion and the other a grinding effect due to high speed fluctuation and spinning of the valve springs. The Brinnell is 226 and the drawing allows 202 to 241. It is not therefore due to a fault of the material. The carbon deposit was heavier than on previous tests. VALVES & FITTINGS to LOP. E.55577. E.56050 Valve stem Packings } To suit Gland E.56051 " Spring washers } mod. sch. 1253. E.53158 Exhaust Valves (S/SLV) E.55606 Inlet Valves (3% N.S.) E.55672 Valve Springs (Closed end type) E.56053 Valve Guides, to suit Gland mod. sch.1253 | ||