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).
Specification comparison between the Lorraine-Dietrich engine and the standard 20 HP R.R. engine.
| Identifier | ExFiles\Box 22\4\ Scan111 | |
| Date | 30th March 1927 | |
| GENERAL DESCRIPTION OF THE LORRAINE-DIETRICH ENGINE. (WITH STANDARD 20 H.P. R.R. FIGURES FOR COMPARISON) | | LORRAINE-DIETRICH. | 20 H.P. R.R. |---|---|---| | BORE. | 75 M/M (2.95 INS) | 3.00 INS. | STROKE. | 130 M/M (5.12 INS) | 4.50 INS. | TOTAL SWEPT VOLUME. | 3444 C.C. | 3127 C.C. | COMPRESSION RATIO. | 5.9 TO 1 | 4.75 TO 1 | CONN. ROD / CRANK RATIO. | 3.54 | 3.53 | RECIPROCATING WEIGHT. | 1.38 LBS | 1.434 LBS. (handwritten correction) | MAXIMUM B.H.P. (WITH SILENCER). | 72.5 (2750 RPM) | 50.0 (2750 RPM) | MAXIMUM B.M.E.P. (WITH SILENCER). | 107.0 (2200 RPM) | 91.0 (1250 RPM) | MAXIMUM COMPRESSION PRESSURE. | 132.5 (2250 RPM) | 94.3 (2250 RPM) | MAXIMUM B.H.P. PER LITRE. (WITH SILENCER). | 21.1 | 16.0 | MAXIMUM VALVE LIFT. (NO TAPPET CLEARANCE). | .375 IN. | .340 IN. | AREA PAST VALVES (FULL LIFT). | 1.61 SQ. INS. | 1.04 SQ. INS. | FREE AREA PAST VALVES / PISTON AREA RATIO. | .2354 | .1472 | VALVE TIMING (.020" TAPPET CLEARANCE). | | | INLET OPENS. | 13° AFTER T.D.C. | 10° AFTER T.D.C. | INLET CLOSES. | 63° AFTER B.D.C. | 34° AFTER B.D.C. | EXHAUST OPENS. | 50° BEFORE B.D.C. | 38° BEFORE B.D.C. | EXHAUST CLOSES. | T.D.C. | 2° AFTER T.D.C. | IGNITION ADVANCE REQUIRED AT MAXIMUM B.H.P. | 33° BEFORE T.D.C. | | INERTIA OF FLYWHEEL. | .3767 LBS. FT² UNITS. | .6911 LBS. FT² UNITS. | CARBURETTORS. | TWO ZENITH TRIPLE VENTURI HORIZONTAL TYPE, EACH FEEDING THREE CYLINDERS. NO BALANCE PIPE. | SINGLE R.R. STD. EXPANDING TYPE. | ||