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).
Comparing Cadillac and Bentley engine valve timings, noting Cadillac's negative overlap and proposing an alternative camshaft for the Spectre.
| Identifier | ExFiles\Box 173\3\ img145 | |
| Date | 13th April 1934 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Lor. c. to By.{R.W. Bailey - Chief Engineer} x USA Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}4/GW.13.4.34. POWER OUTPUTS. ROLLS-ROYCE AND CADILLAC PRODUCTS. Here are the Cadillac M.E.P's. compared with our own on a common base, also the valve timings. The Cadillac sixteen is interesting as it is the same compression ratio as the Bentley. The most noticeable fact is the large amount of negative overlap that is used; we have come to the conclusion that this is one explanation of their excellent slow running and slow speed pulling. We think that we ought to have an alternative camshaft available for SpectreCodename for Phantom III which will enable us to parallel the American results. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||