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).
Engine test issues including magneto failure, leaking cylinder jackets, and valve clearance problems.
| Identifier | ExFiles\Box 43\1\ Scan054 | |
| Date | 19th August 1924 | |
| R.R. 493A (50M) (D.A. 665 20-3-24) J.B.D. -5- EXPERIMENTAL REPORT. Expl. No. REF:HS{Lord Ernest Hives - Chair}3/LG19.8.24. On the 3rd. and 4th. days, a magneto failed from the same cause. The Lodge Plugs were taken out of the engine after the first 10 hrs. run on the bed on account of them shorting between the terminal and the plug body. Difficulty was experienced in cleaning the electrode of these plugs owing to the shield that is around them. Cylinder Jackets. After the 72nd. hr. one of the cylinder jackets was leaking at the welding of the piece let in under the inlet ports. This was quickly followed by others, each leaking at a similar point and all on 'B' side, and by the 79th. hr. 5 cyl. jackets were leaking. One case of another leak developed around the boss for cam case stud (B.5.) On the following day two more cylinder jackets commenced to leak on 'A' side, this time on the exhaust side of the cylinder. Around about this time the general vibrations of the engine were much heavier. A theory as to the cause of the leaking jackets may be advanced as this :- That owing to the large overhang of the induction pipes (alum:) and the heavy vibration that was going on caused the pipes to distort the jacket to a small degree and thus start small cracks in the welding. Valves and Valve Seatings. After running 69 hrs. it was found that the tappet clearances of some of the tappets for exahsut valves were becoming less and washers were taken off the tappets to readjust clearances until at the end of the test all the washers had been taken out of 4 of the tappets and still there was insufficient clearance. contd:- | ||