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).
Measurement data for connecting rod bearings and crankpin dimensions before and after a 15,000-mile test.
| Identifier | ExFiles\Box 97\4\ scan0202 | |
| Date | 24th November 1938 guessed | |
| UNIT No BIII No.5. PASSED TO TEST :- COMPLETED TEST :- CONN: ROD BEARINGS & CRANKPIN DIMENSIONS CONN: ROD BEARINGS :- EX.31509. RUNNING TIME :- 29hrs TEST SEP MATL :- AC.q. DIE CAST. MILEAGE :- 15,000 CRANKSHAFT :- EX.30059 MATL :- .4% CARBON BRINELL 321 TEST PIECE No :- BEARINGS CRANKPIN CLEARANCE No | POSITION | BEFORE | AFTER | WEAR | BEFORE | AFTER | WEAR | BEFORE | AFTER | DIFF. 1 | A-A | 2.00125 | 2.0006 | 0.0065 | 1.999 | 1.987 | 0.003 | 0.0225 | 0.014 | 0.0035 | B-B | | 2.0004 | 0.0005 | | 1.989 | 0.001 | | 0.020 | 0.0025 | OVALITY | | 0.0003 | 0.0003 | | 0.002 | 0.002 | | | 2 | A-A | 2.00125 | 2.00075 | 0.005 | 1.999 | 1.989 | 0.001 | 0.0225 | 0.0185 | 0.004 | B-B | | 2.0005 | 0.0005 | | 1.999 | NIL | | 0.0185 | 0.004 | OVALITY | | NIL. | NIL. | | 0.001 | 0.001 | | | 3 | A-A | 2.00125 | 2.0012 | 0.00005 | 1.999 | 1.988 | 0.002 | 0.0225 | 0.024 | 0.0015 | B-B | | 2.0008 | 0.00015 | | 1.989 | 0.001 | | 0.019 | 0.0035 | OVALITY | | 0.004 | 0.004 | | 0.001 | 0.001 | | | 4 | A-A | 2.00125 | 2.0008 | 0.00045 | 1.999 | 1.999 | NIL | 0.0225 | 0.019 | 0.0035 | B-B | | 2.0010 | 0.00025 | | 1.999 | NIL | | 0.020 | 0.0025 | OVALITY | | 0.002 | 0.002 | | 0.001 | 0.001 | | | 5 | A-A | 2.00125 | 2.0010 | 0.00025 | 1.999 | 1.989 | 0.001 | 0.0225 | 0.021 | 0.0015 | B-B | | 2.0008 | 0.00045 | | 1.999 | NIL | | 0.018 | 0.0045 | OVALITY | | 0.002 | 0.002 | | 0.001 | 0.001 | | | 6 | A-A | 2.00125 | 2.0008 | 0.0025 | 1.999 | 1.988 | 0.002 | 0.0225 | 0.020 | 0.0025 | B B | | 2.0012 | 0.00005 | | 1.989 | 0.001 | | 0.023 | 0.0005 | OVALITY | | 0.004 | 0.004 | | 0.001 | 0.001 | | | GAUGE SIZE :- | ||