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).
Blueprints for Bentley single-cylinder ramp head components, including piston and cylinder head modifications.
| Identifier | ExFiles\Box 86\1\ scan0259 | |
| Date | 3rd May 1938 | |
| [crossed out] HPS{Horace Percy Smith - Experimental Factory Mgr} c. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/[crossed out] Swdl{Len H. Swindell} c. Mr. Brailsford (Alum.Foundry). [handwritten] 219 BY/Ald.{F. Allwood - Experimental Design}10/G.3.5.38. BENTLEY SINGLE CYLINDER - RAMP HEAD. PISTON - SECTION 5040. CYLINDER - SECTION 5050. VALVES AND FITTINGS - SECTION 5060. Please receive herewith two blueprints of each of the following, with an extra print of part marked @ :- SECTION 5050. Ex.S.713 Modification to Cylinder Head. 1 off. Ex.S.716 Modification to Cylinder Head. 1 off. [handwritten signature] Rm{William Robotham - Chief Engineer} @ SECTION 5040. Ex.S.714 Piston 1 off. SECTION 5060. Ex.S.715 Inlet Valve. 1 off. Ex.S.717 Exhaust Valve. 1 off. The above parts have been detailed at the request of memo Rm.{William Robotham - Chief Engineer}9/R.1.4.38. to provide a piston with a bump crown, based on PD.140. Ex.S713 shews a modification to the shape of the existing No.1 cylinder head combustion chamber, to accommodate the bump crown piston. This gives a theoretical compression ratio of 7.3 to 1. This cylinder head should be fitted with the inlet valve Ex.S.715. Ex.S.716 shews a modification to the existing No.2 cylinder head, and enables the larger exhaust valve Ex.S.717 to be fitted. It is intended to use this head with a standard flat top piston for comparison purposes. Kindly instruct one set. It is not intended that a new pattern should be produced for Ex.S.714. The existing pattern for EB.1299, should be temporarily modified to suit. [handwritten annotation next to 'produced': old] BY/Ald.{F. Allwood - Experimental Design} | ||