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 Phantom III and Merlin engine exhaust valve seats, suggesting design changes.
| Identifier | ExFiles\Box 93\4\ scan0109 | |
| Date | 26th February 1937 | |
| 319. Rm.{William Robotham - Chief Engineer} c. BY/CS. BY/SS.{S. Smith}15/W.26.2.37. Phantom III. Exhaust Valve Seats. (Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}3/AP.24.2.37) With reference to the above memo, we have compared the Phantom III Exhaust Seat E.86788 with the latest Merlin Exhaust Seat D.7889. The .003 thread interference on the chassis seat is proportional to the .004 on the aero seat, but to bring the chassis seat up to the best we know in aero practice, we propose to try seats with the full form of thread, and the ½° interference on the conical fitting in the cylinder head. Will E.{Mr Elliott - Chief Engineer} Department please issue drawings calling for these in order that the Experimental Department may approve this assembly. We would also point out that locking slots are not used on the Merlin Inlet Seat D.3076. The thread interference on the Phantom III Inlet Seat E.85063 being proportionately double that of the Merlin Seat, we suggest you consider cancelling the slots on the chassis seat, with a view to reducing the cost. BY/SS.{S. Smith} | ||