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).
Performance graph comparing 1 3/4' and 1 1/4' chokes for a P.I. Unit B.J. 55 for 27 EX engine.
| Identifier | ExFiles\Box 182\M19\ img292 | |
| Date | 23th September 1931 | |
| RM.{William Robotham - Chief Engineer} P.26 23/9/31 P.I. UNIT B.J. 55. FOR 27 EX COMPARISON OF 1 3/4 AND 1 1/4 CHOKES 114° E & 2-448 CAMSHAFT R.R. TWIN CARBS. 4.88 C/R OPEN EXHAUST STANDARD ROCKERS. ① 1 1/4" DIA. CHOKES. ② 1 3/4" DIA. CHOKES. ③ AS 2 BUT WITH AIR SILENCER. B.H.P B.M.E.P. LBS./SQ.IN" SUCTION DEPN INS. HG. | ||