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 for Wraith III and Bentley II engine units, focusing on bore wear, piston, and ring comparisons.
| Identifier | ExFiles\Box 155\2\ scan0253 | |
| Date | 25th October 1938 | |
| -3- Wraith III No.1 Unit. Bore wear tests, 3 liners, in static cast std. R.R. block iron and 3 liners in static cast Chr.Md. alloy. To serve two purposes, carry out tests under condition (c) of head cracking tests but maintain full load running at 3,000 for ¼ hr. before shutting down. (a) Carry out 50 such cycles, remove head examine valve seats and measure the bores for wear. (b) Repeat with Molybdenum cylinder head which HPS{Horace Percy Smith - Experimental Factory Mgr}/FN is now preparing. No.2. Bentley II No.4 Unit. Complete piston comparisons and issue report. Following the above with the original Aerolite pistons we should obtain a ring comparison as follows - (a) Use existing rings and run 1 hr. runs at 4,000 r.p.m. until a consistent result is obtained. (b) Fit a set of Wraith type scrapers and repeat (a) (c) Fit a set of Multivent scrapers and repeat. (d) Fit a set of Bentley type of high pressure scrapers. (e) Cell faced scrapers from Wellworthy. (f) Fit new normal 2nd. compression rings. (g) Fit L section rings in 2nd. compression rings. (2) The chrome molybdenum blocks should be progressed and one fitted to B.II No.4 together with 3 old standard EB.2844 pistons (Aerolite) and 3 similar pistons but having been heat treated at R.R. Oil consumption to be checked to note that it is normal with this type of block. CONT'D.{John DeLooze - Company Secretary} | ||