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).
Letter discussing top speed figures and the performance impact of different engine components like high compression heads and Aerolite pistons.
| Identifier | ExFiles\Box 82\3\ scan0234 | |
| Date | 2nd May 1935 | |
| x200a G.W. Hancock, Esq., c/o.{Mr Oldham} Franco-Britannic Autos Ltd., 12, Avenue George V, Paris (VIII). France. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}16/KW.2.5.35. PER AIR MAIL - URGENT. Many thanks for your note of the 1st May. We are very interested in your top speed figures. We have been confirming the value of the high compression head in England. Lappin took his car on the track and with the cut-out closed lapped at 86.62 m.p.h. and with the cut-out open 88.62 m.p.h. In both cases of course he had Aerolite pistons fitted. We then changed over the high compression head only and he lapped at 89.09 m.p.h. with the cut-out shut and 90.72 m.p.h. with the cut-out open. At the same time as the second test was run he had Fairey's car, B-11-BN{W.O. Bentley / Mr Barrington} on the track, and this lapped at 86.39 m.p.h. with the cut-out open. This of course had standard pistons. From these figures you will see that we have picked up 2 m.p.h. with the cut-out open, high compression head only, and probably 3 m.p.h. total with the high compression head and Aerolite pistons. By-the-way, will you please check that you have the standard size of induction pipe on your engine and not the small bore pipe. Will you also check that your throttles open fully. On Lappin's car we found that the insulation scheme had prevented the accelerator pedal having full travel. We presume you will reproduce Sr's shock absorber setting on 5-B-IV. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||