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).
G.I. compression diagram chart showing pressure against crank angle.
| Identifier | WestWitteringFiles\K\October1923\ Scan57 | |
| Date | 17th October 1925 | |
| GI COMPRESSION DIAGRAM 2000 R.P.M. SPRING RATING 21.2 LBS/□" AVERAGE DIAGRAM COMPR'N PRESSURE 97.5 LBS/□" LBS/□" ABOVE ATMOSPHERIC 100 75 50 25 10 C.C. ATMOS. PR.{Percy H. Rose} LINE 0 10° 20° 30° 40° 50° 60° 70° 80° 90° 100° 110° 120° 130° 140° 150° 160° 170° 180° T.C.F.O. PRINT No. 17. OCT. 25 DERBY | ||