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).
Full throttle engine test detailing seized pistons.
| Identifier | ExFiles\Box 77\3\ scan0018 | |
| Date | 7th November 1919 | |
| Contd. -2- EH1/LG7.11.19. Full Throttle Running. Revs. hours run. 1000 2 1/4 1200 T 9 1/2 1400 5 1500 15 1/2 1600 2 1/4 1700 15 1900 5 2000 7 1/4 At that time the pistons were in very good condition, we could only measure .0005" wear or permanent distortion. When the engine was built up after this inspection, we ran at 2000 R.P.M. full throttle (equal to 60 M.P.H. on top gear). After running 15 hours non-stop, it was noticed that the power fell off slightly. After completing 20 hours non-stop, there was another drop in power so that we stopped down and removed the cylinders. We found on examination that two pistons had seized badly; both pistons had seized on the sides. The fitting portion of the [redacted] pistons at the bottom which is split and which had only very small clearance had not suffered in the least. From our experience of seized pistons we should say that the split saved the fitting portion from seizing. These pistons have been examined by BN{W.O. Bentley / Mr Barrington}, BY, DA{Bernard Day - Chassis Design}, and EP{G. Eric Platford - Chief Quality Engineer} and so far there is no evidence to shew that the seizures were in any way due to the pistons being split. We are sending one of these pistons to Mr. Royce for him to examine. The first point to bear in mind, is that we have (Contd) | ||