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 comparing three different Bentley piston designs with dimensions and test results.
| Identifier | ExFiles\Box 86\2\ scan0039 | |
| Date | 22th August 1933 | |
| PISTON DIMENSIONS BENTLEY First Piston: Dimensions: 3.230, 3.238, 3.247 ORIGINAL 25 HP PISTON E 55350 FITTED TO BENTLEY 1 IN ORIGINAL 10,000 MILES TEST STARTING FEB. 1933 FAILED AFTER 4877 MILES. Second Piston: Dimensions: 3.227, 3.231, 3.240 PISTON EB 5000 AS FITTED TO BENTLEY FOR 10,000 MILES TEST START 20/7/33 FAILED WITH BROKEN SKIRT AFTER 6334 MILES. Third Piston: Dimensions: 3.230, 3.238, 3.240 HS{Lord Ernest Hives - Chair} 1107 MODIFICATION TO EB 500 SENT OUT TO GWH{George W. Hancock - Head Chateauroux} 22/8/33 | ||