| Description | Date | Identifier | |
| Test results and diagram for 20 HP flywheel deflection tests. | 24th Oct 1930 | Box 5 \ 6 06-page083 | |
| Potential solutions for 25 HP engine vibrations, such as using counter-weights or a one-piece crankcase and block. | 5th Nov 1930 | Box 5 \ 6 06-page084 | |
| Experiments to investigate vibrations in a 25 HP engine. | 5th Nov 1930 | Box 5 \ 6 06-page085 | |
| Investigation into engine and flywheel vibrations by testing different crankshaft and flywheel configurations. | 5th Nov 1930 | Box 5 \ 6 06-page086 | |
| Page discussing the disturbing factor of 'long couples' in a six-cylinder crankshaft. | 5th Nov 1932 | Box 5 \ 6 06-page087 | |
| Vibration test data for a 25 HP H.L. Engine, showing crank deflection under various loads. | 6th Nov 1930 | Box 5 \ 6 06-page088 | |
| Data table of load and deflection measurements for No. 6 crank at Top Dead Centre (T.D.C.). | 6th Nov 1931 | Box 5 \ 6 06-page089 | |
| Dimensioned drawing of a control lever assembly. | 7th Nov 1930 | Box 5 \ 6 06-page090 | |
| Request for remarks and criticisms regarding the reduced controls on the steering column. | 7th Nov 1930 | Box 5 \ 6 06-page091 | |
| Further experiments conducted to investigate vibrations on a 25 HP model. | 2nd Nov 1930 | Box 5 \ 6 06-page092 | |
| Analysis of vibration experiments conducted on a 25 HP engine, focusing on crankshaft and flywheel deflections. | 2nd Nov 1930 | Box 5 \ 6 06-page093 | |
| Analysis of crankcase bearing cap distortion, concluding it is due to crankcase web bending. | 21th Nov 1906 | Box 5 \ 6 06-page094 | |
| Blueprint showing a flywheel and No. 6 bearing for a 25 HP engine. | 21th Nov 1906 | Box 5 \ 6 06-page095 | |
| Graph showing crankcase and flywheel deflections for a 25 HP engine under varying loads. | 29th Nov 1930 | Box 5 \ 6 06-page096 | |
| Design modifications to the 25HP clutch flywheel cover, including a new stiffer version and requesting deflection measurements. | 29th Nov 1930 | Box 5 \ 6 06-page097 | |
| Quarterly complaints report detailing tests and issues with various fabric couplings. | 1st Dec 1930 | Box 5 \ 6 06-page098 | |
| Test results for non-spigoted and spigoted fabric coupling spiders. | 1st Dec 1930 | Box 5 \ 6 06-page099 | |
| Test results for various fabric couplings, detailing run time, reversals, and remarks. | 17th Nov 1930 | Box 5 \ 6 06-page100 | |
| Diagram illustrating the causes of failure in fabric coupling tests. | 17th Nov 1930 | Box 5 \ 6 06-page101 | |
| Manufacture, testing, and premature failure of two fabric couplings. | 13th Jan 1931 | Box 5 \ 6 06-page102 | |
| Tests for lost movement in clutch pedal travel on a 25 HP model. | 17th Jan 1931 | Box 5 \ 6 06-page103 | |
| Graph comparing the angular movement versus load for a standard and a lightened 25 HP clutch. | 15th Jan 1931 | Box 5 \ 6 06-page104 | |
| Standardisation of chassis parts for the automatic oiling of the clutch spigot from the gearbox. | 15th Jan 1931 | Box 5 \ 6 06-page105 | |
| Cost and implementation details for fitting a new part to a chassis. | 6th Feb 1931 | Box 5 \ 6 06-page106 | |
| Flywheel vibrations, their causes, and potential engineering solutions. | 6th Feb 1931 | Box 5 \ 6 06-page107 | |
| Improving engine smoothness by modifying pins, webs, and using balance weights to manage vibrations. | 6th Feb 1931 | Box 5 \ 6 06-page108 | |
| 12-cylinder engine design, crankshaft vibration, and potential performance improvements. | 11th Feb 1931 | Box 5 \ 6 06-page109 | |
| Tests conducted on a 25 HP engine to reduce flywheel vibrations by using a double bearing. | 11th Feb 1931 | Box 5 \ 6 06-page110 | |
| Photographic study of flyweight behavior under various conditions and speeds. | 11th Feb 1931 | Box 5 \ 6 06-page111 | |
| Drawing of a 25 HP parallel flywheel bearing. | 20th Feb 1931 | Box 5 \ 6 06-page112 | |
| Investigation of a vibration issue in a Phantom car engine and potential tests using balance weights. | 20th Feb 1931 | Box 5 \ 6 06-page113 | |
| Engine design related to flywheel balance, crankcase stiffness, and vibration issues. | 18th Mar 1931 | Box 5 \ 6 06-page114 | |
| Preliminary drawing and design for a J.3. clutch and flywheel. | 18th Mar 1931 | Box 5 \ 6 06-page115 | |
| Design review memo with suggestions for improving the 'Japan 3 Clutch' to reduce weight, cost, and complexity. | 1st Apr 1931 | Box 5 \ 6 06-page116 | |
| Issues and advantages of fabric couplings on the Phantom II vehicle. | 1st Apr 1931 | Box 5 \ 6 06-page117 | |
| Request to fit a stiffer crankshaft flange and flywheel back plate to the 25 HP model. | 23th Apr 1931 | Box 5 \ 6 06-page118 | |
| Application and testing of a 20/25 flywheel tail bearing. | 13th Jun 1931 | Box 5 \ 6 06-page119 | |
| Request to manufacture parts for a flexible coupling to be fitted to the 25 HP clutch to overcome gear rattles. | 17th Jun 1931 | Box 5 \ 6 06-page120 | |
| Blueprint of a propeller coupling with main circular view and cross-section. | 16th Jun 1931 | Box 5 \ 6 06-page121 | |
| Drilling an experimental oil hole for the 20/25 flywheel tail bearing. | 21th Sep 1931 | Box 5 \ 6 06-page122 | |
| The new N.W. scheme for a flywheel tail bearing and fitting it to a 25 HP car. | 22th Jun 1931 | Box 5 \ 6 06-page123 | |
| The preparation of material for a 20/25 HP flywheel tail bearing. | 26th Jun 1931 | Box 5 \ 6 06-page124 | |
| Issues with a lightened flywheel and the decision to use a standard flywheel with a stiffer flange. | 30th Jun 1931 | Box 5 \ 6 06-page125 | |
| Cancellation of a standardisation sheet for a lightened flywheel on the 25 HP model due to gearbox rattles. | 1st Jul 1931 | Box 5 \ 6 06-page126 | |
| Preparation and allocation of flywheel tail bearing parts for specific cars. | 7th Jul 1931 | Box 5 \ 6 06-page127 | |
| Standard friction ring from a 20/25 clutch, made of Ferodo with interwoven brass wire, and a proposed modification. | 12th Jul 1932 | Box 5 \ 6 06-page128 | |
| Flywheel vibration issues after an attempted fix involving an extra bearing and stiffer flange. | 21th Jul 1931 | Box 5 \ 6 06-page129 | |
| Tests on flywheel vibrations for a 25 HP engine. | 30th Sep 1931 | Box 5 \ 6 06-page130 | |
| Request for a design for fitting a thin flange flywheel to a new 25 HP unit. | 2nd Oct 1931 | Box 5 \ 6 06-page131 | |
| Tests on a 25 HP engine for reducing roughness by modifying the flywheel and balance weights. | 5th Oct 1931 | Box 5 \ 6 06-page132 | |
| Follow-up report on flywheel vibration and the effectiveness of different balance weight schemes for a 25 HP engine. | 19th Oct 1931 | Box 5 \ 6 06-page133 | |
| Request to manufacture a second flywheel with a thinner back plate for chassis No.18.G.IV. | 19th Oct 1931 | Box 5 \ 6 06-page134 | |
| Design of a thin web flywheel for the 'CHINA' chassis. | 1st Oct 1931 | Box 5 \ 6 06-page135 | |
| Requesting modifications to the 25 HP low inertia slipper wheel to prevent sludge collecting. | 24th Oct 1931 | Box 5 \ 6 06-page136 | |
| Blueprint detailing the arrangement, dimensions, and modifications for a driven disc. | 28th Oct 1921 | Box 5 \ 6 06-page137 | |
| Request to test a heavy driven clutch member with the synchromesh box and modify an existing flywheel. | 28th Oct 1931 | Box 5 \ 6 06-page138 | |
| Request to make three sets of damping springs with varying free lengths for a slipper wheel. | 29th Oct 1931 | Box 5 \ 6 06-page139 | |
| Modification request for a Slipper Wheel to prevent sludge collecting in the damper. | 29th Oct 1931 | Box 5 \ 6 06-page140 | |
| Reminder to measure the pedal pressure on the latest 20/25 clutch to apply the information to J. 3. | 17th Nov 1931 | Box 5 \ 6 06-page141 | |
| Confirming the dispatch of scheme 3362, showing the clutch arrangement for J. 3. | 1st Nov 1931 | Box 5 \ 6 06-page142 | |
| Pedal and spring pressure for the 25 HP clutch. | 6th Nov 1931 | Box 5 \ 6 06-page143 | |
| Sending Scheme 3363 for a revised clutch pit, clutch operating gear, and front brake differential. | 1st Nov 1931 | Box 5 \ 6 06-page144 | |
| Difficulties in getting the clutch to stop for gear engagement on various models and the need for a clutch stop or brake. | 6th Nov 1931 | Box 5 \ 6 06-page145 | |
| Test results for 25 HP clutch springs, including load, deflection, and permanent set measurements. | 17th Nov 1931 | Box 5 \ 6 06-page146 | |
| Letter discussing concerns about clutch pedal pressure, gears, and engine rattles on a 25 HP vehicle. | 8th Nov 1931 | Box 5 \ 6 06-page147 | |
| Follow-up letter regarding brake wear, propeller clearance, and engine detonation tests. | 8th Nov 1931 | Box 5 \ 6 06-page148 | |
| Technical memo discussing and comparing clutch spring loads, leverages, and pedal pressures for the 25 HP and 40/50 models. | 21th Nov 1931 | Box 5 \ 6 06-page149 | |
| Request for figures from three specific clutch load tests for a 25 HP model. | 21th Nov 1931 | Box 5 \ 6 06-page150 | |
| The experimental application of features to a 20/25 HP clutch. | 1st Nov 1931 | Box 5 \ 6 06-page151 | |
| Recommendation to cease using automatic clutch spigot lubrication due to issues with oil flooding and clutch slip. | 20th Nov 1931 | Box 5 \ 6 06-page152 | |
| Alterations to prints for clutch components to improve pedal operation. | 12th Dec 1931 | Box 5 \ 6 06-page153 | |
| Instruction to abandon the automatic clutch spigot lubrication system for the 20/25 HP and 40/50 HP models. | 4th Dec 1931 | Box 5 \ 6 06-page154 | |
| Issues with the 25 HP clutch operating mechanism, required modifications, and affected drawing numbers. | 21th Dec 1931 | Box 5 \ 6 06-page155 | |
| Standardisation of stronger clutch springs and modified leverages to suit, in order to overcome slipping. | 5th Jan 1932 | Box 5 \ 6 06-page156 | |
| Fitting of a new part to a chassis, including test date and costs. | 12th Mar 1932 | Box 5 \ 6 06-page157 | |
| Issues with the 25 HP clutch and proposed modifications to address slipping. | 5th Jan 1932 | Box 5 \ 6 06-page158 | |
| Diagram comparing standard and modified leverage for a 25 HP clutch operation. | 1st Jan 1932 | Box 5 \ 6 06-page159 | |
| Technical analysis of 40/50 clutch springs in relation to 25 HP clutch slipping. | 6th Jan 1932 | Box 5 \ 6 06-page160 | |
| Standardisation report for a chemically bonded Ferodo clutch lining with a scarf joint. | 6th Jan 1932 | Box 5 \ 6 06-page161 | |
| Form detailing scheduling and cost information for fitting a new part to a chassis. | 7th Jan 1932 | Box 5 \ 6 06-page162 | |
| Standardisation of chassis parts including Flywheel G.54938, Back Plate G.54939, Oil Catcher G.54940 and Ball Bearing Housing G.54941. | 7th Jan 1932 | Box 5 \ 6 06-page163 | |
| Record detailing the fitting of a new part to a chassis, including test date and associated costs. | 12th Mar 1932 | Box 5 \ 6 06-page164 | |
| Tests on a 25 HP clutch trunnion operating lever for deflection and bending. | 1st Apr 1932 | Box 5 \ 6 06-page165 | |
| Blueprint detailing a deflection test on a 20 HP gearbox main bearing. | 23th Jan 1911 | Box 5 \ 6 06-page166 | |
| Graph showing the results of deflection tests on a 20 HP clutch operating lever. | 29th Feb 1932 | Box 5 \ 6 06-page167 | |
| Trial for a 25HP torsionally flexible joint in the transmission, comparing two design suggestions. | 7th Jun 1932 | Box 5 \ 6 06-page168 | |
| Request to manufacture two sets of 25 HP clutch springs for a customer's car. | 10th Jun 1932 | Box 5 \ 6 06-page169 | |
| Specification sheet for an 8-off 25 HP clutch spring. | 21th Jun 1932 | Box 5 \ 6 06-page170 | |
| Clutch friction coefficients and suggesting tests to determine where losses occur. | 21th Jun 1932 | Box 5 \ 6 06-page171 | |
| Clutch pressure issues, design modifications, and material choices for clutches. | 1st Jul 1932 | Box 5 \ 6 06-page172 | |
| Clutch stiffness due to synchromesh gearboxes, American clutch designs, and a proposed clutch pedal modification. | 1st Jul 1932 | Box 5 \ 6 06-page173 | |
| Information about clutch pedal pressures and the reasons for changes across different series and models. | 8th Jul 1932 | Box 5 \ 6 06-page174 | |
| Technical analysis of clutch separation, torque, coefficient of friction, and performance issues. | 2nd Jul 1932 | Box 5 \ 6 06-page175 | |
| Clutch slip after synchromesh gear changes, comparing solutions from other manufacturers. | 1st Jul 1932 | Box 5 \ 6 06-page176 | |
| Proposal to increase clutch spring force for the 25HP and Phantom II models. | 7th Jul 1938 | Box 5 \ 6 06-page177 | |
| Instructions for fitting an experimental 25HP type driven plate to the J.III clutch, omitting cushioning springs. | 14th Jul 1932 | Box 5 \ 6 06-page178 | |
| Blueprint detailing the design and specifications for a driven plate in a clutch assembly. | 14th Jul 1932 | Box 5 \ 6 06-page179 | |
| Ordering and testing a Borg & Beck clutch fitted to a 25HP model. | 14th Jul 1932 | Box 5 \ 6 06-page180 | |
| Request to expedite building 25 HP clutch springs (Hs.644) into cartridges for testing and a customer's car. | 17th Mar 1932 | Box 5 \ 6 06-page181 | |
| Proposal for a Borg & Beck clutch on a 25HP model. | 22th Jul 1932 | Box 5 \ 6 06-page182 | |
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