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 solid key type bottom tappets for the 40/50 HP Chassis to reduce noise.
| Identifier | ExFiles\Box 171\1\ img054 | |
| Date | 24th September 1926 | |
| RR 288A (10H) (SL 72 18-7-23) MP 274954A COMPLETED 20.10.26 40/50 HP. CHASSIS. ALTERATIONS TO R.R. AERO ENGINE PARTS. [STAMP: CONDOR FALCON HAWK] [STAMP: SANCTION] DATE 24.9.26 X No. 8060 No. 7060 Drawing No. E.74453/4 Part List Air Ministry consent obtained [STAMP: DIFFERENCE in WEIGHT.] 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. "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 Cost of Parts in Works and Stores which will be scrapped if commenced on:— Weight of New Part: Cost of New Part: £10.16.0 Difference per Engine: Difference per Engine: NIL. Signature of Mr. De LOOZE that above is correct: My/Rb.{R. Bowen} 5.10.26 SIGNATURES | DATE | REMARKS [REDACTED] | 25.9.26 | Agreed. CWB. MR. B. JOHNSON | 18.10.26 | Agreed. B.Johnson. MR. ROYCE | 1/10/26 | Agreed FR 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. Re 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 AE MR. HIVES | 24.9.26 | Agreed. HS.{Lord Ernest Hives - Chair} Mr.Northey. | 29.9.26 | Agreed. PN.{Mr Northey} | ||