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).
Investigation into engine piston seizures on the 25/30 HP model.
| Identifier | ExFiles\Box 100\2\ scan0168 | |
| Date | 5th July 1938 | |
| Copy. To By.. from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}19/MH.{M. Huckerby}5.7.38. 25/30 HP. ENGINE PISTON SEIZURE. Further to the memo BY.14/G.29.6.38, in regard to the above and that future decarbonising should include the land above the top piston ring at the same time chamfering the top edge of the piston to reduce the depth of the exposed land, we would also like to recommend that the petrol drain valve at the base of the hot spot be examined to check that it is working and not choked with carbon. We consider the above is well worth while in view of the seizures being confined to No.6. which is consistent with the tilt of the unit in the chassis and petrol getting into this cylinder in the case of a choked drain valve. We are particularly interested in the case of the cars that have had piston seizures, namely GXM.64 Harper, GXM.18-Holloway, and GWN.56-Mills, as to whether the petrol drain valves are choked or not and would like GWH.{George W. Hancock - Head Chateauroux} to see if he can obtain this information, also as to whether sticking of these valves is a common occurence. If this is in any way responsible for these seizures then the remote drain valve i.e. in the drain pipe, away from the hot spot should be incorporated on Wraith. There is only one other reason as far as we can see why the failure should be confined to No.6. piston and that is that this is the hot end of the cylinder block. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||