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 performance and testing of a car fitted with a High Compression Head on Brooklands Track.
| Identifier | ExFiles\Box 155\1\ scan0176 | |
| Date | 15th May 1935 | |
| /W. Rm{William Robotham - Chief Engineer} To Sg.{Arthur F. Sidgreaves - MD} from Lp.{Mr Lappin} Copy to Bn.{W.O. Bentley / Mr Barrington} Lp.{Mr Lappin}11/LAM.15.5.35. Re: 4.B.IV. I do not know whether you want me to make a point of letting Mr. Fedden try the above car. which is fitted with a High Compression Head. The car has done close on 2,000 miles since the head was fitted, and there is an entire absence of detonation when running on B.P. or Pratt's Ethyl. The car has been on Brooklands Track twice, and, on each occasion when driven by Bn.{W.O. Bentley / Mr Barrington} and self, showed a lap speed of over 90 M.P.H. The half mile under favourable conditions was run at 95.74 M.P.H. The engine is smooth and quiet throughout the speed range, and with the H.C. head reaches maximum R.P.M. more rapidly and more frequently than is the case with the standard head. The body is insulated. Lp.{Mr Lappin} | ||