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).
Performance report on engine and clutch components following mileage testing.
| Identifier | ExFiles\Box 101\1\ scan0274 | |
| Date | 15th April 1936 guessed | |
| ( 2 ) VALVES & FITTINGS LOP E.{Mr Elliott - Chief Engineer} 60405 Complete to above LOP incorporating :- EB. 2588/9 Rocker Arms. - EB. 2854 Rocker Shaft Inclination of .125" dia.hole altered from 8° to 5° in accordance with alt. 18065/E.{Mr Elliott - Chief Engineer} E.{Mr Elliott - Chief Engineer} 60420 Valve Springs. - E.{Mr Elliott - Chief Engineer} 60824 Wedge. Ex.21131 Inlet Valve S/SLV .310" dia. stems. Ex.21132 Exh. Valve KE.965 .341" dia. stems. Not stellite seats. A failure of a valve occurred after 9,797 miles. The head of N° 10 Exhaust broke off which caused a broken piston and connecting rod. It had been noted during the early part of the test, that Nos. 2,3,7,10, & 11, Exhaust valves were losing clearance. N° 2 lost .010" max. N° 10 lost .008". No further loss of clearance took place after 7800 miles and there was no indication of valve failure up to the time of the breakage. These were standard 25 HP. valves. The condition of the seating showed deep pitting marks. Upon dismantling, the pocket and valve of N° 10 exhaust indicated over-heating. The Inlet Valves lost no clearance and were in good condition. PISTONS LOP E.60761 LEC 4744 6-E.{Mr Elliott - Chief Engineer} 60.634 Gudgeon Pins. No piston knock was heard during the mileage. The oil consumption which at first was considerable,became normal with the bedding in of the piston rings. All rings were free in the grooves and drain holes free when examined. The bedding of the pistons was good, slight hard mark at the top band of the skirt. CONNECTING RODS. LOP. EB.2704. Halls solid metal Bigend Bearings. EB.2224/5. Conn. Rods and cap mod. to BV.87. When examined the bearings showed no sign of cracks, the bearing surface was smooth with good bedding. FLYWHEEL & CLUTCH. LOP. G.57097. Complete to the above LOP incorporating :- Borg & Beck 11.A.3 Clutch. Driven plate lined with moulded material. Thrust bearing with oilite cage fitted to trunnion. Lubrication cut off from thrust bearing not from sliding surfaces and stirrup pegs. NS.{Norman Scott} 4723-4752 Pull off springs & stop for Clutch Pedal. Modifications to Clutch casings & operating levers for 11" Borg & Beck clutch. I-G257150 Operating lever. Ransome & Marles L.J.25.Z. bearings with oilite cages. The engagement of the clutch was smooth and remained consistently good. For traffic work the decreased load on the pedal was appreciated. No sign of slipping occurred and there was no measurable wear of the fabrics. Handwritten text: SWDL{Len H. Swindell} MATTHEWS L.P. Smith | ||