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).
Series of engine power and camshaft comparison graphs for various engine models.
| Identifier | ExFiles\Box 124\2\ scan0302 | |
| Date | 21th May 1940 | |
| Top Left Graph: B.80 POWER THREE 1-5/8" S.U. CARBS. IGN. SYSTEM: "MOCK UP" CYLINDER HEAD PIECE NO. EB.4091. CAPACITY 125 CCS. C/R 6.35:1 CAMSHAFT PIECE NO. E.B.4105 VALVE TIMING AT .030 TAPPET CLEARANCE:- I.O. 1-2° ATDC I.C. 40° ABTD. E.O. 42.5° BBDC. E.C. 4.5° BTDC. FUEL: 'POOL' Legend: OPEN EXHAUST OPEN EXHAUST. AIR SILENCER FITTED. TWIN EXHAUST SYSTEM. FUEL: 'ETHYL' TO AVOID DETONATIONS FUEL: 'POOL' Axes: B.M.E.P, B.H.P, R.P.M. Top Right Graph: B.80 CAMSHAFT COMPARISON POWER ETHYL PETROL COMP. RATIO 6:1 IGN. PIPE CARBURETTER STROMBERG AA.{D. Abbot-Anderson}25 PISTONS EB 3916 EXS 925 (1-600) Legend: ① CAMSHAFT E.B. 4105 (TIMING @ .030 CLCE) I.O. 11-2° AT. E.O. 42.5° BB. I.C. 39° AB. E.C. 4° BT.{Capt. J. S. Burt - Engineer} ② CAMSHAFT E.B. 4512 (TIMING @ .030 CLCE) I.O. 11° AT. E.O. 41.5° BB. I.C. 30° AB. E.C. 4° BT.{Capt. J. S. Burt - Engineer} A= OPEN EXH. B= SILENCED. (B.T. COMPLETE) Axes: B.H.P, R.P.M. Bottom Left Graph: ALL ROAD WHEEL CURVES IN DIRECT GEAR. TEST BED CLUTCH H.P. WITH DUCK AIR & EXHAUST SILENCERS 30 G VIII POWER ENGINE UNIT B.80 NO.1 AXLE RATIO 3.37 HUB H.P OF COMPLETE MOTOR CAR. THIS IS THE POWER AVAILABLE FOR ACCELERATION & TO OVERCOME TYRE & WIND RESISTANCES. INCREASE IN POWER AVAILABLE AT THE ROAD BY REMOVING THE FAN. THIS IS BASED ON FIGURES FOR AN ENGINE IN STILL AIR & PROBABLY DOES NOT HOLD FOR A CAR IN MOTION POWER AVAILABLE AT THE ROAD. THIS IS THE HUB H.P. OF THE COMPLETE MOTOR CAR MINUS THE TYRE LOSS FOR ALL FOUR WHEELS USING DUNLOP TYRES @ 35 LB/IN² Axes: B.H.P. CORRECTED TO C.A.V. STD TEMP., ENGINE R.P.M. Bottom Right Graph: COMP. RATIO 6.2:1 Legend: ① CAMSHAFT E.B. 4105 (TIMING @ .030 CLCE) I.O. 11-2° AT E.O. 42.5° BB I.C. 39° AB E.C. 4° BT{Capt. J. S. Burt - Engineer} ② CAMSHAFT EX. 33975 (TIMING @ .030 CLCE) I.O. 11-2° AT E.O. 46.5° BB I.C. 31.5 AB E.C. 3° BT{Capt. J. S. Burt - Engineer} A= OPEN EXH. B= SILENCED (B.T. COMPLETE) Axes: B.H.P, R.P.M, APPROX M.P.H. IN DIRECT GEAR USING 7-50 x 16 TYRES | ||