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).
Modifications for Ph.III valve seat inserts to prevent them from coming loose.
| Identifier | ExFiles\Box 96\2\ scan0259 | |
| Date | 15th October 1937 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. By/CS. c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}5/AP.15.10.37. 354 Ph.III. valve seat inserts. Regarding the several isolated cases we have had of exhaust valve seats coming loose in the cylinder heads and in view of the latest aero practice, will you please detail seats as follows. We should like these as quickly as possible in order that we may incorporate on 39-EX. before going for 15,000 miles test. Exhaust Seats (a) To have full form thread. (b) Existing interference fit on thread (c) ½° interference on the conical face in the cylinder head. (d) In S/SLV. material. (e) Otherwise as E.88171. Inlet Seats Incorporating exhaust seat mods. as (a), (b), (c) and (d) and additionally deleting the locking slots. Otherwise as E.88170. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||