Performance graph comparing different tappet clearances on a Peregrine engine with a 105.5° camshaft.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page194 | |
| Date | 29th June 1932 guessed | |
| BEST TIMING WITH THE 105.5° CAMSHAFT. RM. {William Robotham - Chief Engineer} PR8 ALTERING THE TAPPET CLEARANCE PEREGRINE(Experimental Bentley car never produced / Aero Engine) 1 5/8 S.U. OPEN EXHAUST. PLUG REACH .950. 5.85 C/R VALVES DIA: & LIFT AS ON RM. {William Robotham - Chief Engineer} PR5. Graph Key: ① INLET .004, EXHAUST .020 ② INLET CLCE .020, EX. CLCE .020 Diagram 1 Valve Timing: EX. OPENS 38° BEFORE BDC EX. CLOSES 38.5° AFTER TDC IN. OPENS 6° BEFORE TDC IN. CLOSES 9° AFTER BDC CLEARANCE .020 Diagram 2 Valve Timing: EX. OPENS 40° BEFORE BDC EX. CLOSES 31° AFTER TDC IN. OPENS 17° BEFORE TDC CLEARANCE .020 Axes: Vertical Left: B.H.P. Vertical Right: B.M.E.P. LBS/SQ" Horizontal: R.P.M. VARYING TAPPET CLEARANCE | ||
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).