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 a stainless steel throttle piston's fit and dimensions under thermal stress.
| Identifier | ExFiles\Box 50\3\ Scan251 | |
| Date | 13th November 1922 | |
| X.4305 Mr. Hives. from GWH. {George W. Hancock - Head Chateauroux} 13.11.22 The throttle piston made of stainless steel - dia. at start 2.249 fitted into throttle body - after 7th. test Piston slightly stiff at start but became very easy immediately heat was applied. After 10 mins. running dia. of piston was 2.2515" When cold it came back to 2.249" and was quite free . A further test of half an hour was taken and when cold only a very slight stiffness was noticed. Standard throttle piston gound .0015" under size was quite free when cold and after half an hour run there was no sign of tightness after cooling down. Throttle 2.255 + .001 - .001" Piston 2.248 + .0005" - .0005". GWH. {George W. Hancock - Head Chateauroux} | ||