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).
Testing stronger valve springs for increased engine speed.
| Identifier | ExFiles\Box 80\3\ scan0169 | |
| Date | 1st October 1913 | |
| X290 From Exp. Dept. Copies for: J.{Mr Johnson W.M.} R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} Na.{Mr Nadin} October 1st. 1913. Wor{Arthur Wormald - General Works Manager}/EH14/L11013. Re Stronger Valve Springs for increased speed. K.449 We have tested some strong Valve Springs, they were intended to allow the valves to leave the cams at 2500 revs., but with these springs the valves did not jump until 2750 revs. Strength of the spring 62 lbs at normal load. They have run 8000 miles at 2000 revs, and two springs have broken, one after 4500 miles and one after 6700 miles. These springs are the same as regards weight of metal, dia. of wire and number of coils, as the ones we tested with a normal load of 42 lbs so that they were very much less stressed; when running like that they did not last as long, 8 broke in 5000 miles. | ||