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).
Comparing bone grey fibre to red fibre and Continental Bakelite, noting moisture issues on 20 HP models.
| Identifier | ExFiles\Box 69\1\ scan0340 | |
| Date | 1st June 1924 | |
| R.R. 496A (20H) (D.A. 652 20-3-24) J.H.D. +4646 EXPERIMENTAL REPORT. Expl. No. REF Hs{Lord Ernest Hives - Chair}4/LG30. 6.24. X2738 +4646 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} WOR.{Arthur Wormald - General Works Manager} BONE GREY FIBRE. We find that the bone grey fibre is affected by moisture in the same way as the ordinary red fibre. We have had considerable trouble with fibre on the 20 HP. Slipper Wheels, although we have used the same material on the 40/50 HP. from the very earliest cars and have not had any trouble with it. The only reason we can see why fibre gives on the 20 HP. is that there must be slight water leakage from the cylinder head joint to the crankcase. The trouble has always been most marked on cars which have stayed in the Coachbuilders . a car which is continually in service, does not seem to suffer in the same way. We have had cases of leakage from the joint down the tubes in the cylinder and so into the crankcase, so that it does not get into the cylinder. We are using Continental Bakelite for the discs on the 20 HP. This material is not affected in any way by moisture and has approximately the same co-efficient of friction as fibre. Continental Bakelite is being used for the rubbing material on the contact breaker arm for battery ignition both 20 HP. and 40/50 HP. On the whole we have had very little trouble. Tests are being made with the grey fibre, so far it has shewn no outstanding advantage. Hs.{Lord Ernest Hives - Chair} | ||