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).
Wear measurements for main bearings, connecting rod bushes, and crankshaft journals for Chassis B.60.GA.
| Identifier | ExFiles\Box 146\3\ scan0122 | |
| Date | 21th October 1936 | |
| For Rm.{William Robotham - Chief Engineer} Levallois VA2/ET.21.10.36 CHASSIS B.60.GA - Job N° 35747 Report upon wear of main bearings, connecting rod bushes and crankshaft journals. ------------------------------------------------------------------------------------------------ N°1 N°2 N°3 N°4 N°5 N°6 N°7 I - CRANKSHAFT Maximum and minimum 2.2485 2.2485 2.2485 2.2485 2.2485 2.2485 2.2485 diameters of the 2"2485 2"248 2"248 2"248 2"24825 2"24825 2"24825 main journals 2"247 2"24775 2"24675 2"247 2"24725 2"24725 2"24725 Ovality .0015 .00025 .00125 .001 .001 .001 .001 2 - Diameter of 1.9985 1.9985 1.9985 1.9985 1.9985 1.9985 --- crankpins 1"9985 1"9985 1"999 1"99875 1"99875 1"9985 --- 3 - Internal diameter 2.2515 2.2515 2.2515 2.2515 2.2515 2.2515 2.2515 of main bearings A.{Mr Adams} 2"252 2"252 2"252 2"2525 2"253 2"253 2"254 taken in two B. 2"2485 2"2485 2"250 2"2485 2"250 2"2505 2"2525 planes, viz. "A" and "B". Please refer to sketch attached. 4 - Internal diameter 2.001 2.001 2.001 2.001 2.001 2.001 --- or big end bearings 2"0015 2"0015 2"0015 2"001 2"0015 2"00175 --- measured vertically NOTE: We find, as far as it is possible to measure, that there is not very much wear of the bearing surface of the bearings; the bearings however, have hammered in their cages, which has caused them to wear externally. Certain of the intermediate bearings in particular are deformed, due to the hammering effect, and they have "closed in" near the top sides, as per attached sketch. It will be observed that N°6 bearing is by far the worst in this respect. The hammering effect which must have been more pronounced on certain of the intermediate bearings caused them to pinch on the corresponding crankshaft journal. The upper bearings of the connecting rods also show very marked signs of having hammered in the rods, which has caused a certain amount of wear externally. As far as this can be determined, we find that the upper half of the big end bearings have worn from .001" to .0015" (externally). Considering that the car has only covered a total mileage of 23.065 Kms., the main journals of the crankshaft cannot be considered to be in a good condition. Apart from the wear outlined above they are, to a certain extent, scored. VA.Vd | ||