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).
The wear measurements of engine bores and pistons for a Chevrolet (GA) chassis.
| Identifier | ExFiles\Box 103\2\ scan0018 | |
| Date | 3rd April 1939 | |
| REPORT RE WEAR IN BORES & PISTONS. ================== Fitter: Pass & Joyce Chassis No.: Chevrolet (GA) Job No.: Date: 3. 4. 1939 Mileage: 20,491 TABLE 1: BORE | NOMINAL | TAPER | OVAL | M | C | T 1 | 3.500" | +.004" | .0015" | 1/2 | 4 | 2 | " | +.003" | .0015" | 1/2 | 3 | 3 | " | +.003" | .001" | 1/2 | 3 | 4 | " | +.002" | .001" | 1/2 | 2 | 5 | " | +.002" | .001" | 1/2 | 2 | 6 | " | +.002" | .001" | 1/2 | 2 | SMALL ENDS:- REMARKS:- TABLE 2: PISTONS | TYPE | TOP | BOTTOM. 1 | 2 | Cast iron 3 | Slipper type pistons. 4 | 5 | 6 | Signature: J.B. | ||