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).
Report comparing high power single and twin-inlet cylinder heads with a standard head, including a detailed table of specifications.
Identifier | ExFiles\Box 134\2\ scan0015 | |
Date | 27th May 1935 | |
- 2 - Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead}2/GB.27.5.35. sodium cooled exhaust valve helps to subdue this high speed detonation and in the case of the twin-inlet head, prevents it occurring at all. RATE OF PRESSURE RISE. Indicator cards taken with the high power heads show an abnormally high rate of pressure rise. Up to the time of writing little success has been achieved in attempts to reduce this rate of pressure rise and it is inferred that it is only local and will not necessarily result in roughness. DETAILED REPORT. COMPARISON OF HIGH POWER HEADS AND STANDARD. | | Single Inlet H.P. Head. | Twin Inlet H.P. Head. | Standard. | |---|---|---|---| | Compression ratio ...... | 6.07 - 6.61 | 6.13 - 6.8 | 6.4 | | Inlet valve diameter ... | 1.750" | 1.225" (two) | 1.400" | | Exhaust valve diameter . | 1.500" | 1.500" | 1.300" | | Area past inlet valve(s) | 2.295sq.in. | 2.220 sq.in. | 1.450 sq.in. | | Area past exhaust valve | 1.655 sq.in. | 1.655 sq.in. | 1.160 sq.in. | | Valve lift (inlet(s) (exhaust | .400" .400" | .325" .400" | .400" | | Inlet port diameter | 1.625" | 1.625" | 1.350" | | Exhaust port diameter | 1.500" | 1.500" | 1.350" | | ||