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).
Specifications for the adaption of a Kestrel short duration high lift camshaft.
| Identifier | ExFiles\Box 102\5\ scan0088 | |
| Date | 28th September 1931 guessed | |
| 85090. 25 H.P. Adaption of Kestrel short Duration High Lift Camshaft E.36951. BASE O of this cam .950 instead of 1.050 We are therefore using a square cam follower .050 deeper and of radius .750 to suit the cam form (Hs.{Lord Ernest Hives - Chair}351) We shall lengthen the valve stem .200 and raise the rocker pedestal .200. The tappet has sufficient adjustment for this. We are making two camshafts to Hs.{Lord Ernest Hives - Chair}349/50 of angle between the cams 118° and 114°. Suggested timings :- [Left Diagram] 105 EC7 IC65 EO53 114° [Center Text] .020 CLEARANCE DURATION IN AND EX 240° [Right Diagram] 10 T ECH IC60 EO50 118° Cam lift is increased from .283 to .364 by .081 Valve " " " " .377 to .485 " .108 Valve springs we are fitting to Hs.{Lord Ernest Hives - Chair}313. | ||