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).
Table of measurements for cylinder bore diameter and wear after 16,000 miles.
| Identifier | ExFiles\Box 179\2\ img078 | |
| Date | 17th December 1931 | |
| CX{Major Len W. Cox - Advertising Manager} - 19 GTV 17-12-31 BORES OF CYLINDERS AFTER 16000 MILES BORE N° | MEASURED AT | DIAMETER | WEAR 1 | CROWN | 3.2515 | .0015 1 | CENTRE | 3.2515 | .0015 1 | MOUTH | 3.251 | .001 2 | CROWN | 3.2513 | .0013 2 | CENTRE | 3.2514 | .0014 2 | MOUTH | 3.2507 | .0007 3 | CROWN | 3.2517 | .0017 3 | CENTRE | 3.2516 | .0016 3 | MOUTH | 3.2507 | .0007 4 | CROWN | 3.2515 | .0015 4 | CENTRE | 3.2514 | .0014 4 | MOUTH | 3.2505 | .0005 5 | CROWN | 3.2514 | .0014 5 | CENTRE | 3.2514 | .0014 5 | MOUTH | 3.2506 | .0006 6 | CROWN | 3.2513 | .0013 6 | CENTRE | 3.2515 | .0015 6 | MOUTH | 3.2506 | .0006 DRAWING SIZE 3.250 +1 DIA | ||