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 different camshaft configurations for the Spectre engine with an open exhaust and 6:1 compression ratio.
| Identifier | ExFiles\Box 93\5\ scan0012 | |
| Date | 13th February 1935 | |
| X307 SP.{Mr Spinney} 13 SPECTRECodename for Phantom III CAMSHAFT COMPARISONS. OPEN EXHAUST. COMPRESSION RATIO 6:1 B.V.42 / 13.2.35 GRINDING SEMI-SPLIT BIG ENDS LEGEND: ① No 2 UNIT HS{Lord Ernest Hives - Chair} 1536 CAMSHAFT. AEROLITE PISTONS. LEAD BRONZE BIG ENDS. ② CALCULATED CURVE OF No.2 UNIT USING SEMI-SPLIT PISTONS. FROM BENTLEY RESULTS. ③ No 1 UNIT - E.86371 CAMSHAFT. WHITEMETAL BEARINGS. SEMI-SPLIT PISTONS (E84546). AXIS LABELS: B.H.P. R.P.M. MEP LBS/SQ" DIAGRAM 1 (Left): HS.{Lord Ernest Hives - Chair}1536 CAMSHAFT .020 CL'CE TDC EC 7° IO 7° BDC IC 53° EO 48° DIAGRAM 2 (Right): E.86371 CAMSHAFT .020 CL'CE TDC EC 4° IO 4° BDC IC 39° EO 45° STAMP: 13-2-35 | ||