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).
Heavy thud in an engine, speculating it's a worn crankshaft bearing, and requesting an inspection.
| Identifier | WestWitteringFiles\E\September1920\ Scan27 | |
| Date | 4th October 1920 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to CUT. " " HM.{Capt. W. Hallam - Head Repairs} " " EFC. R HAS A HEAVY THUD IN 1EX: ENGINE ASKS IF WE CAN COME TO W.W. AT AN EARLY DATE R6/U29/9/20. WW Does HS{Lord Ernest Hives - Chair}, EP{G. Eric Platford - Chief Quality Engineer}, OR HM{Capt. W. Hallam - Head Repairs} KNOW IT? ORIGINAL RECEIVED 4 OCT 1920 X.3763. RE 1 EX. please note to WHA HEAVY THUD NO With reference to 1 EX. you will remember that a very long time ago I said this engine had a revolution knock when running light. I have noticed that lately this revolution knock appears to be a thud, especially noticeable when the engine is hot. It is a heavy thud which can be felt throughout the engine, and I think must be in the crankshaft. It appears to be at its worst at about 1,000 engine revs. when pulling hard. I do not think it can possibly be a longitudinal movement of the crankshaft, but fear it is a crankshaft main bearing or intermediate bearing which has worn or given way. It has never been without oil since I had it, and I did not notice this thud previous to the time it was returned to me by your driver, who arrived with it with the treads worn right off. These wheels were sent back to you, and I kept the ones with good tyres which were at the time on 6 EX. Perhaps the engine got a really good hammering at the same time as these treads were worn so badly, possibly by PN.{Mr Northey} If you do not know what this thud is, I should be pleased if you would endeavour to come to West WitteringHenry Royce's home town at an early date, if some other work arises about which you think it is advisable for you to see me. The thud is of the nature that can be felt more than heard, and is perceptible to the passenger as well as the driver; -probably you, EP{G. Eric Platford - Chief Quality Engineer}, or HM.{Capt. W. Hallam - Head Repairs} would know it well? R.{Sir Henry Royce} | ||