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).
Graph comparing the performance of different exhaust manifolds on a Spectre No. 1 unit.
| Identifier | ExFiles\Box 93\1\ scan0014 | |
| Date | 7th February 1935 | |
| SP{Mr Spinney} 10 COMPARISON OF EXHAUST MANIFOLDS ON SPECTRECodename for Phantom III N° 1 UNIT E 84546 SEMI-SPLIT PISTONS WHITEMETAL MAIN & BIG ENDS RUNNING WITHOUT SILENT TAPPETS AT .006 CLEARANCE SHORT BEND TO EACH EXHAUST PORT BUILT UP MANIFOLDS TO LEC 4184 ORIGINAL CAST MANIFOLD TO LEC 3793 TIMING WITH .020 CLCE E 85255 CAMSHAFT TDC EC 8° IO 3° IC 52° EO 50° B.H.P R.P.M M.E.P LBS/D" N.H.S. 7-2-35 | ||