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).
Crankshaft journal and crankpin dimensions and bearing condition for Chassis B.74.GA.
| Identifier | ExFiles\Box 146\3\ scan0215 | |
| Date | 9th December 1936 | |
| Piles To Bentley Motors Ltd. DERBY ..................Rm.{William Robotham - Chief Engineer} Swdl{Len H. Swindell} 1020 Levallois Sr/VA28/GM.9.12.36 re: Chassis B.74.GA - Mr. Le Blanc Mileage 20385 Kms. With reference to our Sr/VA29/GM.8.12.36 the following are the dimensions of the crankshaft journals: Main journals ( Max. & Min.dia) 1 2"248 2"247 2 2"247 2"246 3 2"247 2"2455 4 2"247 2"246 5 2"2465 2"2455 6 2"247 2"2455 7 2"24775 2"24625 Ovality .001" .001" .0015" .001" .001" .0015" .0015" Crankpins: 1"9985 1"997 (1"9985 1"997) 1"9985 1"9985 1"9985 1"9985 -- You will observe that n°. 2 crankpin has suffered due to the hammering and then failure of the Connecting rod bolts. Please let us have your opinion re the crankshaft wear. We have checked the bow at the centre of the crankshaft and find same to be .010". MAIN BEARINGS HALL'S METAL: The surface of the main bearings are in a poor state, n°. 6 bearing is very badly scored. We will send you measurements of the bearings tomorrow, our intention was to send them to you today, but owing to Sr. and myself having paid a visit to the Bugatti Repair W-or ks this afternoon, we have only been able to prepare the above information for you in time to catch this evening post. We had an interesting time at Bugatti's and Sr. has asked me to tell you that he will drop you a line concerning some information which we obtained. Sr/VA. | ||