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).
Analysis of the Lincoln Car's engine, detailing the change from a seven-bearing to a four-bearing crankshaft.
| Identifier | ExFiles\Box 173\1\ img314 | |
| Date | 1st February 1934 | |
| LINCOLN CAR H S There is a considerable amount of interest attached to this power unit, particularly as they have this year changed from a seven bearing forked big end construction, to a side by side four bearing type. The four bearing shaft is fully balanced. The balance weights are forged integral with the shaft. The engine is now 3-1/8 x 4-1/2 Firing order 1-4-9-8-5-2-11-10-3-6-7-12 Angle between the cylinders 67° Crankshaft dimensions: Journal dia. 2.625" Pin dia. 2.5 Pin length 1.995 (less than 1"/rod) Main bearings A - 1.628" long " " B - 3.5" Front " C - 1.875 Distance between adjacent cylinders 3.8" approximately " " 2 & 3, etc. " 5.125" Over all length of crank from flywheel flange to front of main bearing C 31.7" Finished crank weight 80 lbs. Worst period presumably 6/rev. without damper load (they have a fair hub) 2,200 R.P.M. The Lincoln people make the statement that they have changed to the four bearing engine entirely from an engine smoothness point of view and not from price considerations. It is difficult to make any comparisons between the two designs because the car we tried in England had more rubber in the engine mounting and about 5-1 C/R against 6.1 C/R of the new job. Actually I tried two of the latest cars, and whilst they were improved with regard to suspension, front end steadiness, etc. consider the engines were definitely rougher, however, the general impression here seems to be that at present, to get a smooth engine with 6-1/R or over. it is the exception | ||