| Description | Date | Identifier | |
| Borg & Beck clutch experiment on a 25HP model, including suggested modifications and schematics. | 23th Aug 1932 | Box 5 \ 6 06-page183 | |
| Schemes for revised leveranges for the 20/25 Clutch. | 25th Aug 1932 | Box 5 \ 6 06-page184 | |
| Faults and modifications for the Peregrine & J.S. Clutch mechanism. | 9th Sep 1932 | Box 5 \ 6 06-page185 | |
| Confirmation of a phone message regarding the redesign and simplification of the J.J. & Peregrine clutch. | 16th Sep 1932 | Box 5 \ 6 06-page186 | |
| Slipping clutches on 25 HP models due to automatic lubrication and the solution to disable it. | 23th Sep 1932 | Box 5 \ 6 06-page187 | |
| Issues and design corrections for single and multi-plate clutches. | 11th Oct 1932 | Box 5 \ 6 06-page188 | |
| Testing of three modified clutches and a patent application for an improved actuating mechanism. | 4th Oct 1932 | Box 5 \ 6 06-page189 | |
| Suggested modification to the 25HP clutch to align it with improvements made for other models. | 18th Oct 1932 | Box 5 \ 6 06-page190 | |
| Three methods for achieving satisfactory engagement in single-plate clutches. | 12th Dec 1932 | Box 5 \ 6 06-page191 | |
| Archival note referencing the location of previous correspondence. | 2nd Jan 1931 | Box 5a \ 1 01-page001 | |
| Potential engine specification changes for the 25HP model, considering bore, stroke, and overall capacity. | 2nd Jan 1931 | Box 5a \ 1 01-page002 | |
| Proposed engine modifications and performance issues with vehicle 18-EX on rough roads. | 3rd Jan 1931 | Box 5a \ 1 01-page003 | |
| Compromise for a 4.5 litre engine for the 20/25 HP model. | 3rd Jan 1931 | Box 5a \ 1 01-page004 | |
| Proposing a modification to the 25HP induction stand pipe to improve starting. | 6th Jan 1931 | Box 5a \ 1 01-page005 | |
| The standardization of parts following the testing of vehicle 18-G4 in France. | 6th Jan 1931 | Box 5a \ 1 01-page006 | |
| List of modifications to be standardized as a result of a 107,000 mile test on chassis 18-0-IV. | 6th Jan 1931 | Box 5a \ 1 01-page007 | |
| List of modifications and updates for various vehicle components. | 6th Jan 1931 | Box 5a \ 1 01-page008 | |
| List of specifications and modifications for various engine components and assemblies. | 6th Jan 1931 | Box 5a \ 1 01-page009 | |
| Performance implications of increasing the 25 HP engine's displacement to 4.7 litres, with weight comparisons to a Chrysler chassis. | 6th Jan 1931 | Box 5a \ 1 01-page010 | |
| Preliminary specification of 25HP. chassis. | 8th Jan 1931 | Box 5a \ 1 01-page011 | |
| Outlining design suggestions for a new chassis, focusing on cost-saving measures and component interchangeability. | 9th Jan 1931 | Box 5a \ 1 01-page012 | |
| 20/25 HP chassis fitted with a Brewster body and dummy shutters, and a wooden subframe for Phantom II cars. | 9th Jan 1931 | Box 5a \ 1 01-page013 | |
| Design specifications for the 25HP model, including the back axle, gearbox, and radiator. | 1st Jan 1931 | Box 5a \ 1 01-page014 | |
| Relaying a telegram regarding a specification agreement with Japan and proposing the design name 'Japan II'. | 13th Jan 1931 | Box 5a \ 1 01-page015 | |
| Preliminary general arrangement and modifications for a 28HP engine. | 13th Jan 1931 | Box 5a \ 1 01-page016 | |
| Page discussing the production flow and balance of R.H. and L.H. chassis. | 15th Jan 1931 | Box 5a \ 1 01-page017 | |
| New work programme, project progress, and the assignment of draughtsmen. | 15th Jan 1931 | Box 5a \ 1 01-page018 | |
| Outlining a proposed development and testing programme for an improved 20/25 HP model. | 5th Jan 1931 | Box 5a \ 1 01-page019 | |
| Production schedules, material ordering, and tooling for various chassis types. | 5th Jan 1931 | Box 5a \ 1 01-page020 | |
| Continued memorandum discussing manufacturing strategies, cost reduction, and production planning for chassis and aero programmes. | 16th Jan 1931 | Box 5a \ 1 01-page021 | |
| The design of a connecting rod for the 26 HP Chassis. | 16th Jan 1931 | Box 5a \ 1 01-page022 | |
| Cover memo for a compiled list of economy suggestions and decisions, with a mention of further suggestions from a meeting. | 16th Jan 1931 | Box 5a \ 1 01-page023 | |
| List of suggestions to reduce the cost of the 25HP chassis and the decisions made. | 31th Dec 1930 | Box 5a \ 1 01-page024 | |
| Technical document outlining potential design changes and cost savings for various vehicle components. | 31th Dec 1930 | Box 5a \ 1 01-page025 | |
| Potential cost savings on various vehicle components. | 31th Dec 1930 | Box 5a \ 1 01-page026 | |
| Discussion document on potential cost savings and design improvements for the magneto, gearbox selector, and gearbox covers. | 31th Dec 1930 | Box 5a \ 1 01-page027 | |
| Potential cost savings on various gearbox components and the carburetter. | 31th Dec 1930 | Box 5a \ 1 01-page028 | |
| Cost-saving analysis for various engine components. | 31th Dec 1930 | Box 5a \ 1 01-page029 | |
| Potential cost savings on various automotive components through design modifications. | 31th Dec 1930 | Box 5a \ 1 01-page030 | |
| Potential cost-saving measures on various vehicle components. | 31th Dec 1930 | Box 5a \ 1 01-page031 | |
| Potential cost savings on frame, steering, and brake components. | 31th Dec 1930 | Box 5a \ 1 01-page032 | |
| Potential cost savings from modifying undershields, brakes, and radiator cross members. | 1st Jan 1931 | Box 5a \ 1 01-page033 | |
| Proposed modifications to the rear axle and brake gear for a car with a larger engine. | 1st Jan 1931 | Box 5a \ 1 01-page034 | |
| Supply of information and workflow for the 'JAPAN III' project. | 18th Jan 1931 | Box 5a \ 1 01-page035 | |
| Status update on crankcase and cylinder design for the 'JAPAN III' project, referencing various drawings. | 18th Jan 1931 | Box 5a \ 1 01-page036 | |
| Continued memorandum detailing work on induction pipes, oil supply, and cylinder components. | 18th Jan 1931 | Box 5a \ 1 01-page037 | |
| Proposing the name 'JAPAN III' for the 28 HP chassis to prevent confusion. | 20th Jan 1931 | Box 5a \ 1 01-page038 | |
| Secret internal memorandum regarding the preliminary specification for the 20/25 Japan III model. | 20th Jan 1931 | Box 5a \ 1 01-page039 | |
| Preliminary specification for a new car model, codenamed 'Japannth'. | 8th Jan 1931 | Box 5a \ 1 01-page040 | |
| Series of suggestions for a new chassis design, focusing on cost-saving measures and component interchangeability for a 25HP model. | 8th Jan 1931 | Box 5a \ 1 01-page041 | |
| Typed page discussing the production flow balance of right-hand and left-hand chassis. | 20th Jan 1931 | Box 5a \ 1 01-page042 | |
| Proposal to use a right-hand engine in a 'Japan 3' left-hand drive chassis. | 20th Jan 1931 | Box 5a \ 1 01-page043 | |
| The 'Japan III' project, discussing the development and expenditure on left-hand drive chassis. | 1st Jan 1921 | Box 5a \ 1 01-page044 | |
| Design modifications and simplifications for the 'Japan Engine'. | 21th Jan 1931 | Box 5a \ 1 01-page045 | |
| Design note with a sketch of a starter handle shaft tube, with a related telegram confirmation on design simplicity. | 21th Jan 1931 | Box 5a \ 1 01-page046 | |
| Revisions to the 'Japan 3' engine scheme, including shaft diameters and cylinder skirts. | 22th Jan 1931 | Box 5a \ 1 01-page047 | |
| Modifications to the petrol tank for the 'Japan 3' project, including increased capacity and simplified construction. | 23th Jan 1931 | Box 5a \ 1 01-page048 | |
| Modifications to the design of torque arms, engine suspension, and gear arrangement for the 'JAPAN 3' project. | 24th Jan 1931 | Box 5a \ 1 01-page049 | |
| Design considerations for the 'Japan 3' engine, focusing on spring drive, bearings, and crankchamber casting. | 28th Jan 1931 | Box 5a \ 1 01-page050 | |
| Review of faults on the 'Japan III' 25 HP car, specifically addressing issues with exhaust pipes and slipper wheels. | 26th Jan 1931 | Box 5a \ 1 01-page051 | |
| Engine vibrations, dynamo output, and ignition complaints for the 25 HP car. | 26th Jan 1933 | Box 5a \ 1 01-page052 | |
| The development of carburettors, petrol pumps, shock absorbers and starter motors. | 26th Jan 1933 | Box 5a \ 1 01-page053 | |
| Blueprint Loc. 2869, illustrating the proposed arrangement of units for both right and left-hand chassis. | 27th Jan 1931 | Box 5a \ 1 01-page054 | |
| Proposed arrangement of engine accessories for Japan III, with rear timing gears suitable for either right-hand or left-hand steering. | 21th Jan 1931 | Box 5a \ 1 01-page055 | |
| Design proposals and arrangements for the 'Japan 3' engine. | 21th Jan 1931 | Box 5a \ 1 01-page056 | |
| Sketches and notes on the design of a monocle plate, crossmember, and bearing arrangements. | 29th Jan 1931 | Box 5a \ 1 01-page057 | |
| Confidential summary discussing engine vibrations, balancing, design schemes for 'Japan 3', and a proposed new engine configuration. | 29th Jan 1931 | Box 5a \ 1 01-page058 | |
| Technical discussion on engine vibrations, flywheel instability, and potential design improvements. | 29th Jan 1931 | Box 5a \ 1 01-page059 | |
| Engine balancing, crankshaft stresses, steering issues, and the choice of a 12-cylinder engine for high speeds. | 29th Jan 1931 | Box 5a \ 1 01-page060 | |
| 'Japan 3' engine design, comparing 6 and 12-cylinder configurations. | 29th Jan 1931 | Box 5a \ 1 01-page061 | |
| Engine design choices for the Japan 3 engine, including crank pins, ignition, and connecting rod lengths. | 29th Jan 1931 | Box 5a \ 1 01-page062 | |
| Breakage of a low inertia slipper wheel, crankshaft vibrations, and engine performance concerns. | 1st Feb 1931 | Box 5a \ 1 01-page063 | |
| Flywheel vibration issues and potential solutions for the Japan 3 engine. | 2nd Mar 1931 | Box 5a \ 1 01-page064 | |
| Specification of switches, instruments, and lamps for the 'Japan III' project, with comparisons to a Humber car. | 26th Feb 1931 | Box 5a \ 1 01-page065 | |
| Inclusion of clocks, front aprons, and bonnet ventilators on car chassis. | 24th Feb 1931 | Box 5a \ 1 01-page066 | |
| Modifications to the Japan S. Engine, specifically the connecting rod and cylinder head. | 14th Feb 1931 | Box 5a \ 1 01-page067 | |
| Design modifications and suggestions for various engine components. | 14th Feb 1931 | Box 5a \ 1 01-page068 | |
| The design modifications for valve gear pedestals and end cylinder studs. | 1st Feb 1931 | Box 5a \ 1 01-page069 | |
| Confidential memo discussing the competitive threat of the 8-litre Bentley and its performance characteristics compared to the Phantom II. | 1st Feb 1931 | Box 5a \ 1 01-page070 | |
| Challenges of developing a 12-cylinder car ('double 28HP') in time for the 1931 Show, considering other company commitments and past failures of similar large cars. | 1st Feb 1931 | Box 5a \ 1 01-page071 | |
| Confidential memo discussing the purchase of a 12-cylinder Cadillac for competitive analysis and developments in gear ratios and new models. | 5th Feb 1931 | Box 5a \ 1 01-page072 | |
| Confidential letter regarding Bentley's success and the importance of competitive analysis. | 5th Feb 1931 | Box 5a \ 1 01-page073 | |
| Proposed modifications to the Japan 3 Engine, concerning connecting rod length and flywheel/clutch assembly. | 1st Feb 1931 | Box 5a \ 1 01-page074 | |
| Design changes and stress calculations for cylinder studs, a valve cover, and spark plug holes. | 6th Feb 1931 | Box 5a \ 1 01-page075 | |
| With a sketch discussing the design and manufacturing methods for a cast dashboard for the Japan III model. | 6th Feb 1931 | Box 5a \ 1 01-page076 | |
| Layout and sourcing of controls and instruments for the Japan 3 chassis. | 6th Feb 1931 | Box 5a \ 1 01-page077 | |
| Secret memorandum calling a conference to discuss progress on the 'JAPAN III' car project, noting delays and reaffirming the goal of selling cars. | 3rd Mar 1931 | Box 5a \ 1 01-page078 | |
| Secret memorandum discussing the layout and features of vehicle controls for the 'Japan 3' project. | 6th Feb 1931 | Box 5a \ 1 01-page079 | |
| Design considerations and problems for the 'Japan 3' engine, including flywheel fixing, bearings and valve types. | 7th Feb 1931 | Box 5a \ 1 01-page080 | |
| Accompanying a revised drawing with modifications, noting it is not to scale but includes necessary dimensions. | 7th Feb 1931 | Box 5a \ 1 01-page081 | |
| Two proposed modifications to the Japan S. engine concerning the combustion chamber and crankpin diameter. | 1st Feb 1931 | Box 5a \ 1 01-page082 | |
| Calculations for the cone mounting on the 'JAPAN 3' engine's rear end, referencing print Lec.2877. | 28th Feb 1931 | Box 5a \ 1 01-page083 | |
| Design proposals for the engine's front-end suspension and fan pulley drive. | 28th Feb 1931 | Box 5a \ 1 01-page084 | |
| Performance improvements for the 25 HP engine, detailing modifications and test results at Brooklands. | 13th Mar 1931 | Box 5a \ 1 01-page085 | |
| Comparison table of quarter-mile and lap speeds for various car models and chassis configurations. | 28th Apr 1930 | Box 5a \ 1 01-page086 | |
| Progress report on the 'Japan 3' E. & D. Sections project, detailing component status and drawing numbers. | 14th Mar 1931 | Box 5a \ 1 01-page087 | |
| List of drawing numbers and completion status for various engine component sections. | 14th Mar 1931 | Box 5a \ 1 01-page088 | |
| Status list of drawing numbers for various engine and chassis components. | 14th Mar 1931 | Box 5a \ 1 01-page089 | |
| Table outlining drawing numbers and remarks for various vehicle electrical components. | 16th Mar 1931 | Box 5a \ 1 01-page090 | |
| Analysing a chart from Rolls-Royce of America regarding a proposed 25 HP car engine in comparison to American competitors. | 16th Mar 1931 | Box 5a \ 1 01-page091 | |
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