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).
Fuel consumption comparisons and mechanical failures including piston seizure, cracked valves, valve springs and push rods.
| Identifier | ExFiles\Box 134\2\ scan0020 | |
| Date | 27th May 1935 | |
| - 7 - Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead}2/GB.27.5.35. and a loss of power is experienced. If both plugs are in use, the power output is the same as with the better position only. FUEL CONSUMPTION. Comparing the High Power Head at 6.5/1 ratio with the standard Bentley at 6.4/1, the former shows a progressive improvement in specific consumption from nil at 1500 R.P.M. to .075 pts/BHP/Hr. at 4250 R.P.M. MECHANICAL TROUBLES. PISTON SEIZURE. After running 182 hours 15 minutes the Aerolite piston seized and was badly scored. This seizure occurred shortly after fitting the high power type cylinder and no definite reason could be found for the failure. CRACKED INLET VALVE. Two instances of inlet valve failure have occurred on the single inlet valve high power head after running 21 hrs. 50 mins. and 18 hrs. 35 mins. Both these valves were of the flat-head type (E.B.1995). INLET VALVE SPRINGS (INNER). On three occasions the inner inlet valve spring (EB.2101) has fractured (single inlet high power head). The running times were 13 hrs. 30 mins; 5 hrs. 50 mins. and 9 hrs. 5 mins. PUSH ROD FAILURE. After 33 hrs. 20 mins. running the push rod (inlet) fractured. | ||