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).
Test procedures and modifications for engine units N 11 No 4 and Bentley 11 S No 19.
| Identifier | ExFiles\Box 155\2\ scan0298 | |
| Date | 9th August 1938 guessed | |
| -3- No 2 Test House. N 11 No 4 Unit. Following initial oil consumption test on the above unit, return to the shop for examination and measurement of special cylinder block together with pistons and rings. Cylinder block which is in CR{Mr Cra???ster / Mr Chichester} MO alloy has Brico short inserts. Following inspection, the fitters should be supplied with tin-plated rings for further oil consumption tests under same conditions as previously run. Future consumptions should be accompanied by 'blow by' figures. When the above is complete, fit standard non plated rings, but with L section (Wraith) second compression ring. Repeat as above. Bentley 11 S No 19. This unit is being assembled for Bentley S chassis. Is fitted with the following:- 1. New main and big end bearings (production) with .00025- .0005 more clearance than STD. 2. Strengthened T T pistons. 3. Le Mans cylinder head (capacity should be checked to determine compression ratio before running) 4. 1 7/8 T T induction system T T type - Tests should comprise. (a) Careful running in on De Laval oil (b) Open exhaust power on Ethyl. (c) With minimum power loss exhaust system say duplex as tried on B V.{VIENNA} No. 1 check non detonating power and ignition advance required as against maximum power and required advance (d) Take 1 hour consumption at 4000 RPM dependant upon result whether repeated (keep record of tappet clearance start and finish) (e) Check valve bounce speed. (f) Carburations to be checked over Cont'd.{John DeLooze - Company Secretary} | ||