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).
Performance graph comparing a modified SG's engine against the average performance of Bentley and Wraith engines.
| Identifier | ExFiles\Box 109\5\ scan0124 | |
| Date | 3rd March 1939 | |
| Sg{Arthur F. Sidgreaves - MD}'s ENGINE TESTED ON UNIT BED NEW CYL. BLOCK NEW CAMSHAFT (BENTLEY) NEW PISTONS 3-3-39 H.P. AVERAGE BENTLEY AVERAGE WRAITH Sg.{Arthur F. Sidgreaves - MD} ENGINE R.P.M. | ||