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).
Blueprint detailing a modification for air vent grooves in a piston.
| Identifier | ExFiles\Box 105\3\ scan0304 | |
| Date | 26th October 1938 | |
| GROOVE .032" X .012" AT TOP OF PISTON #2 #2 REMOVE ALL SHARP EDGES. AIR VENT GROOVES IN PISTON - N SCH 3517. MODIFICATION TO F59291/2/3. HS{Lord Ernest Hives - Chair} 741 26-10-38 | ||