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).
The condition and wear of C17 unit valves after 13,600 miles in France and England.
| Identifier | ExFiles\Box 101\2\ scan0263 | |
| Date | 5th March 1937 | |
| C17 UNIT VALVES BEFORE & AFTER 13,600 MILES IN FRANCE & ENGLAND. INLET VALVES E 60892 S/SLV EXHAUST VALVES E 61043 KE965 (STELLITE) INLET VALVES No | LENGTH A (New | After | Diff.) | DIA. C (New | After | Wear) 1 | 4.434 | 4.433 | -.001 | .3095 | .3090 | .0005 4 | 4.434 | 4.434 | NIL | .3099 | .3095 | .0004 5 | 4.432 | 4.432 | NIL | .3098 | .3095 | .0003 8 | 4.434 | 4.434 | NIL | .3097 | .3093 | .0004 9 | 4.432 | 4.431 | -.001 | .3095 | .3093 | .0002 12 | 4.431 | 4.431 | NIL | .3097 | .3095 | .0002 EXHAUST VALVES No | LENGTH A (New | After | Diff.) | DIA. C (New | After | Wear) 2 | 4.425 | 4.419 | -.006 | .3402 | .3398 | .0004 3 | 4.425 | 4.420 | -.005 | .3401 | .3397 | .0004 6 | 4.425 | 4.419 | -.006 | .3403 | .3400 | .0003 4 | 4.431 | 4.423 | -.008 | .3402 | .3398 | .0004 10 | 4.427 | 4.426 | -.001 | .3402 | .3399 | .0003 11 | 4.433 | 4.431 | -.002 | .3401 | .3396 | .0005 INLET VALVES No | DIMENSION 'A' (New | After | Difference) | DIMENSION 'B' (New | After | Difference) | AVERAGE EXTENT OF POCKETING 1 | 1.125 | 1.133 | .008 | 1.123 | 1.1315 | .0085 | .0083 4 | 1.095 | 1.1055 | .0105 | 1.094 | 1.101 | .007 | .0088 5 | 1.0995 | 1.105 | .0055 | 1.094 | 1.1055 | .0115 | .0085 8 | 1.115 | 1.124 | .009 | 1.111 | 1.120 | .009 | .009 9 | 1.093 | 1.100 | .007 | 1.089 | 1.099 | .010 | .0085 12 | 1.095 | 1.123 | .0135 | 1.104 | 1.117 | .013 | .0133 EXHAUST VALVE SEATS RE-CUT IN FRANCE DIAGRAM ANNOTATIONS: Top view of No. 11 Valve: VALVE SEAT BADLY BURNT No.s 6 & 7 SIMILAR No. 11 VALVE Side view of No. 11 Valve: SEAT PITTED BAD CRACK EXTENDING FROM EDGE TOWARDS THE STEM FOR ~.175" VALVE SEAT BADLY BURNT No. 11 VALVE BURNT & DISTORTED No. 10 SIMILAR, BUT NOT SO BAD. CONDITION OF VALVES. INLETS - GOOD, Nos 8 & 12 SLIGHTLY "PITTED". EXHAUSTS - BAD - 6, 7, & 11 - SEATS BURNT. 10 & 11 CRACKED. 3, 6, 7, & 11 DISTORTED. C.W.W. | ||