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).
Alterations to aero engine parts, specifically solid key type bottom tappets to make them quieter.
| Identifier | ExFiles\Box 66a\2\ scan0040 | |
| Date | 24th September 1926 | |
| RR 288A (10H) (SL '72 18-7-23) MP 274954A X8060 40/50 HP. CHASSIS. COMPLETED 20.10.26 ALTERATIONS TO R.R. AERO-ENGINE PARTS. Description of Parts SOLID KEY TYPE BOTTOM TAPPETS. Origin To produce a more consistent quiet tappet. The present tappets are difficult to get quiet. Experimental Test Report With the present standard bottom tappets 80% of the engines have to be dismantled to quieten the tappets. With the new type tappets, 3 sets have been made and fitted to production cars - Test Dept. report all were quiet. We do not say all new tappets will be quiet but the design lends itself to more consistent quietness and if 50% of these are quiet there will be a big saving in time. It is necessary to dismantle the whole of induction side of engine to quieten tappets. contd. on attached sheet. Box 1: CONDOR, EAGLE, FALCON, HAWK DATE 24.9.26 X No. 8060 / 7060 Drawing No. E.74453/4 Part List Air Ministry consent obtained Difference in weight "A"—Scrap and replace at all costs. "B"—Scrap and replace on those engines in Works. "C"—Scrap present stock and replace on all engines not yet handed to test. "D"—Use up existing stock. Alteration effective on future engines. Signature of Expl. Dept. that above is correct Weight of Old Part Cost of Old Part £10-16-0 Weight of New Part Cost of New Part £10-16-0 Difference per Engine Difference per Engine £ Nil Cost of Parts in Works and Stores which will be scrapped if commenced on:— Signature of Mr. De LOOZE that above is correct. COSTS ARE SAME. My R/L 5/10/26 SIGNATURES | DATE | REMARKS MR. JOHNSON | 25.9.26 | Agreed. CWB. MR. B. JOHNSON | 13.10.26 | Agreed. B.Johnson. MR. ROYCE | 1.10.26 | Agreed. FHR. MR. WORMALD | 27.9.26 | Agreed. Wor.{Arthur Wormald - General Works Manager} MR. ROWLEDGE | 27.9.26 | Agreed. Rg.{Mr Rowledge} MR. DAY | 1.10.26 | Agreed. Da.{Bernard Day - Chassis Design} MR. BAILEY | 11.10.26 | Agreed. BY.{R.W. Bailey - Chief Engineer} MR. PLATFORD | 27.9.26 | Agreed. EP.{G. Eric Platford - Chief Quality Engineer} Advantage I take it is that they are also likely to remain quieter than present type. MR. ELLIOTT | 1.10.26 | Agreed. E.{Mr Elliott - Chief Engineer} MR. HIVES | 24.9.26 | Agreed. Hs.{Lord Ernest Hives - Chair} Mr. Northey. | 29.9.26 | Agreed. PN.{Mr Northey} | ||