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 comparison graph of E.R. Hall's Unit versus a Standard Bentley Unit for the 1934 Ulster T.T.
| Identifier | ExFiles\Box 90a\2\ Scan103 | |
| Date | 7th September 1934 | |
| COMPARISON OF E.R.HALL'S UNIT & STANDARD BENTLEY UNIT. ULSTER T.T. 1934 ALL TESTS OPEN EXHAUST NO AIR INTAKE PLUGS K.L.G 827 FILE 124/H1 STANDARD UNIT 1.4 INLET 1.3 EX. STANDARD PISTONS STD. CAMSHAFT E.B. 1085 (113°) 6.45 COMP. RATIO HALL'S UNIT 1.5 INLET. 1.2 EX. AEROLITE PISTONS. STD. CAMSHAFT 7.75 COMP. RATIO B.H.P. B.M.E.P. R.P.M. HALLS UNIT STANDARD UNIT R.M. 7/9/34 | ||