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).
Gear ratio calculations based on engine revs and horsepower.
| Identifier | ExFiles\Box 90a\4\ Scan153 | |
| Date | 5th May 1936 | |
| -3- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/KW.5.5.36. The gear ratio is still in the air, but attached is a copy of a letter I have written to Hall on the subject. Briefly, he did 4300 revs. with his existing car down the straight for 132 H.P. What gear ratio ought he to have to do the same speed with the 4 1/4 litre engine, giving 160 H.P. You might check up that I have approximated correctly. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||