| Description | Date | Identifier | |
| Design of the J. 3 connecting rod, referencing drawing LeC. 2932. | 8th Mar 1931 | Box 103 \ 2 scan0180 | |
| The design and evolution of lubricating grooves for main bearings and con-rods in aero and car engines. | 10th Feb 1933 | Box 103 \ 2 scan0181 | |
| Query regarding when to perform a split-pin job on connecting rod bolts for the 20/25 HP model. | 21th Mar 1933 | Box 103 \ 2 scan0182 | |
| Cancelling a previous notice concerning connecting rod bolts for the 20/25 HP model. | 2nd Mar 1933 | Box 103 \ 2 scan0183 | |
| Two designs for drilled up connecting rods for the Bentley and 20-HP models. | 5th Jul 1933 | Box 103 \ 2 scan0184 | |
| Implementation of standardized connecting rods with oil tubes for the 20/25, Bentley, and A.2. series chassis. | 21th Sep 1933 | Box 103 \ 2 scan0185 | |
| Recommendation to adopt a modified oil pipe fixing from the Bentley for model 18-G4 after a 10,000-mile test failure. | 23th Sep 1933 | Box 103 \ 2 scan0186 | |
| Standardisation of parts for drilled up connecting rods. | 23th Feb 1934 | Box 103 \ 2 scan0187 | |
| Print of an aluminium Connecting Rod for the 20/25 model designed by the Bohn Aluminium Co. of America. | 3rd May 1934 | Box 103 \ 2 scan0188 | |
| Modifications to a drop-forged connecting rod for the 25-30 HP and Bentley models. | 6th Jan 1936 | Box 103 \ 2 scan0189 | |
| Requesting the weight of a 25/30 HP forged connecting rod before committing to the production of sinking dies. | 13th Jan 1936 | Box 103 \ 2 scan0190 | |
| Instruction to modify the 25/30 connecting rods to match the specifications of the large bore Bentley, specifically regarding the oil feed hole. | 25th Feb 1936 | Box 103 \ 2 scan0191 | |
| Responding to a verbal enquiry about coined connecting rods, referencing a scheme for the 25/30 HP car. | 27th Jan 1937 | Box 103 \ 2 scan0192 | |
| Experimental testing of 25/30 connecting rods made direct from a new forging process. | 28th Jan 1937 | Box 103 \ 2 scan0193 | |
| Reinforcing the 20HP Chassis engine suspension tube to prevent bending. | 22th Mar 1926 | Box 103 \ 2 scan0194 | |
| Modifications to the 20 HP crankshaft and connecting rod, increasing the crankpin diameter and oval web width. | 10th Dec 1927 | Box 103 \ 2 scan0195 | |
| Potential engine improvements, including the crankshaft, cylinder head, and induction system. | 28th Feb 1928 | Box 103 \ 2 scan0196 | |
| Four propositions for modifying the 20 HP cylinder for the India Chassis models. | 15th Mar 1928 | Box 103 \ 2 scan0197 | |
| Design, positioning, and lubrication of an adjustable carrier wheel. | 31th Mar 1928 | Box 103 \ 2 scan0198 | |
| Blueprint for the INDIA 3 crankshaft and bearings, focusing on lubrication systems and design alterations. | 17th Apr 1928 | Box 103 \ 2 scan0199 | |
| Crankchamber material and crankshaft lubrication with a diagram. | 24th Apr 1928 | Box 103 \ 2 scan0200 | |
| Modifications to the India 3-cylinder block to accommodate larger valves. | 29th Jun 1928 | Box 103 \ 2 scan0201 | |
| Four-point engine mounting scheme for the India 1V model. | 2nd Feb 1929 | Box 103 \ 2 scan0202 | |
| Confirming a telegram and detailing modifications for increasing the bore of the 20 HP chassis engine. | 21th Apr 1929 | Box 103 \ 2 scan0203 | |
| Pattern alterations for a series of 150 'twenty's' based on drawing LeC.2696. | 23th Apr 1929 | Box 103 \ 2 scan0204 | |
| Modifications to the G.4 engine crankcase and 4-point mounting. | 23th Apr 1929 | Box 103 \ 2 scan0205 | |
| Providing an initial assessment and review of a 20 HP Allweather car, model 16-G4. | 26th Jun 1929 | Box 103 \ 2 scan0206 | |
| Investigation into an oil leak from the crankcase to the flywheel case on a 20 HP chassis. | 2nd Oct 1929 | Box 103 \ 2 scan0207 | |
| Investigation into crankcase and flywheel case pressures and modifications to the breather system. | 2nd Oct 1929 | Box 103 \ 2 scan0208 | |
| Crankcase and flywheel case air pressure, detailing tests and modifications to manage it. | 2nd Oct 1929 | Box 103 \ 2 scan0209 | |
| Production recommendations following a test of crankcase and breather modifications on 20 HP and Phantom models. | 20th Aug 1930 | Box 103 \ 2 scan0210 | |
| The brake thud and carburation performance of a 25 HP car (Japan). | 20th Aug 1930 | Box 103 \ 2 scan0211 | |
| High engine oil consumption and the need to increase crankcase oil capacity. | 28th Aug 1930 | Box 103 \ 2 scan0212 | |
| Tests carried out to resolve an oil leak from the No. 7 bearing on a 25 HP chassis. | 28th Aug 1930 | Box 103 \ 2 scan0213 | |
| Oil leaks from the gearbox and No.7 bearing on a 25 HP model, with proposals for modification. | 23th Mar 1930 | Box 103 \ 2 scan0214 | |
| Testing a one-piece cast iron cylinder block and crankcase for a 20 HP engine. | 29th Aug 1930 | Box 103 \ 2 scan0215 | |
| Brakes, the instruction book, and potential crankchamber modifications for the 25 HP Japan model. | 1st Sep 1930 | Box 103 \ 2 scan0216 | |
| Response regarding a temporary brake failure and extra oil in the crankcase for a 25 HP car in Japan. | 8th Sep 1930 | Box 103 \ 2 scan0217 | |
| Requesting to expedite the completion of an experiment on a 20 HP cast iron cylinder block and crankcase. | 23th Sep 1930 | Box 103 \ 2 scan0218 | |
| Development of a 20 HP cast iron monobloc engine, requesting a casting. | 5th Nov 1930 | Box 103 \ 2 scan0219 | |
| Redesign of the 25HP crankchamber to increase its oil capacity. | 10th Nov 1930 | Box 103 \ 2 scan0220 | |
| Increase of the recommended quantity of oil in the crankcase for 20/25 HP and 40/50 HP engines. | 13th Nov 1930 | Box 103 \ 2 scan0221 | |
| Proposed modification to the sump oil level gauge for the 25 HP engine. | 18th Nov 1930 | Box 103 \ 2 scan0222 | |
| Proposed design changes for a 25HP chassis engine. | 11th Dec 1930 | Box 103 \ 2 scan0223 | |
| List of proposed engineering modifications for an engine and associated components. | 20th Dec 1930 | Box 103 \ 2 scan0224 | |
| Crankshaft balancing, crankchamber stiffness, and engine vibration for 25HP and 45HP engines. | 20th Dec 1930 | Box 103 \ 2 scan0225 | |
| Proposed improvements to the 25HP and 45HP engines and chassis, specifically regarding crankshafts, suspension, and clutches. | 14th Jan 1931 | Box 103 \ 2 scan0226 | |
| Requesting the assembly of parts for testing a cast iron crankcase. | 14th Jan 1931 | Box 103 \ 2 scan0227 | |
| Technical memo detailing the results of tests on 25.HP. crankcase distortion and stiffness. | 20th Jan 1931 | Box 103 \ 2 scan0228 | |
| Blueprint of a 25 HP crankcase (inverted top half) showing the setup for measuring main bearing deflection. | 20th Jan 1931 | Box 103 \ 2 scan0229 | |
| Graph showing crankcase deflections under various loads and conditions for a 25 HP engine. | 26th Jan 1931 | Box 103 \ 2 scan0230 | |
| Proposal to increase the diameter of the crankcase oil filler, which is considered too small, for the 28 HP chassis. | 26th Jan 1931 | Box 103 \ 2 scan0231 | |
| Design of the oil filler for the crankcase to allow for direct pouring from a can. | 28th Jan 1931 | Box 103 \ 2 scan0232 | |
| Mathematical investigations into the benefits of heavy crankshafts and stiff crankcases for the 25 HP engine. | 11th Feb 1931 | Box 103 \ 2 scan0233 | |
| Front end of the crankcase, cross drive, and future proposals for a slipper flywheel and engine suspension. | 12th Mar 1931 | Box 103 \ 2 scan0234 | |
| Prints for the Japan 3 crankcase lower half, oil strainer, and oil level indicator. | 14th Mar 1931 | Box 103 \ 2 scan0235 | |
| On a 25 HP integral crankcase and cylinder block, comparing its performance against a standard unit. | 1st Apr 1931 | Box 103 \ 2 scan0236 | |
| Experimental results regarding car construction, efficiency, and performance. | 20th Apr 1931 | Box 103 \ 2 scan0237 | |
| Positive test results of a 20/25 HP engine with an integral crankcase and cylinder block, recommending its adoption. | 21th Apr 1931 | Box 103 \ 2 scan0238 | |
| From Sg. to Hs. regarding the 20/25 Oil Sump Capacity, enclosing related correspondence. | 27th Apr 1931 | Box 103 \ 2 scan0239 | |
| Customer feedback on the small oil capacity of the 20/25 model and a proposal to increase it. | 23th Apr 1931 | Box 103 \ 2 scan0240 | |
| Arguing against the use of cast iron crank chambers due to concerns about weight, performance, and brand reputation. | 24th Apr 1931 | Box 103 \ 2 scan0241 | |
| Increase of oil sump capacity for the 20/25 & J.3 models. | 25th Apr 1931 | Box 103 \ 2 scan0242 | |
| Increase in the oil sump capacity for the 20/25 HP model. | 29th Apr 1931 | Box 103 \ 2 scan0243 | |
| Standardisation of chassis parts to increase engine sump oil capacity to 1.25 gallons. | 29th Apr 1931 | Box 103 \ 2 scan0244 | |
| Form for standardizing chassis parts, detailing the fitting of a new part and associated costs. | 5th Sep 1931 | Box 103 \ 2 scan0245 | |
| The results of deflection tests on a 25 HP crankcase. | 19th Aug 1931 | Box 103 \ 2 scan0246 | |
| Blueprint diagram illustrating the setup of an indicator clock on the centre main bearing of a 25 HP inverted top half crankcase. | 19th Aug 1931 | Box 103 \ 2 scan0247 | |
| Graph showing crankcase deflections under various loads for a 25 HP engine. | 29th Aug 1931 | Box 103 \ 2 scan0248 | |
| The sending of a drawing print for the J.3. Crankcase, Cylinder Block, and Crankshaft. | 29th Aug 1931 | Box 103 \ 2 scan0249 | |
| Print of drawing Lec. 2943 for a J.3 Crankcase, detailing covers, dynamo mounting, and studding. | 5th Sep 1931 | Box 103 \ 2 scan0250 | |
| General scheme for the crankcase, cylinder block, and crankshaft. | 1st Sep 1931 | Box 103 \ 2 scan0251 | |
| Design change to the suction pipe for the J.3. Oil Base End Filter. | 12th Sep 1931 | Box 103 \ 2 scan0252 | |
| The J.3 crankcase cover, dynamo, water pump suspension, and pump drive coupling. | 21th Sep 1931 | Box 103 \ 2 scan0253 | |
| New single-unit oil level indicator, its features, and its intended use on the Peregrine engine. | 26th Sep 1931 | Box 103 \ 2 scan0254 | |
| Modifications to the crankshaft and crankcase, referencing blueprints to enable ordering of forgings. | 26th Sep 1931 | Box 103 \ 2 scan0255 | |
| Conclusions on engine balance weights, flywheel vibrations, and crankchamber deflections. | 28th Sep 1931 | Box 103 \ 2 scan0256 | |
| The dispatch of drawings for the redesigned Japan 3 crankcase and dynamo drive. | 28th Sep 1931 | Box 103 \ 2 scan0257 | |
| Drawings for a crankcase, oil pump installation, front suspension, and electric starter. | 29th Sep 1931 | Box 103 \ 2 scan0258 | |
| Cover note regarding modifications to the dynamo drive and rear end of the crankcase. | 3rd Oct 1931 | Box 103 \ 2 scan0259 | |
| Sending an original drawing of a crankshaft and crankcase and updating a blueprint. | 10th Mar 1931 | Box 103 \ 2 scan0260 | |
| Modifications and additions to the J.3 crankcase. | 15th Oct 1931 | Box 103 \ 2 scan0261 | |
| Dynamo and crankcase for Bensport and 20/25 HP engines. | 10th Feb 1933 | Box 103 \ 2 scan0262 | |
| Trial for a sheet metal baffle for the 20/25 HP crankcase breather. | 31th Mar 1933 | Box 103 \ 2 scan0263 | |
| Instruction memo regarding a replacement Crankcase and experimental larger Oil Filler for the 20/25 HP Chassis. | 26th Jul 1933 | Box 103 \ 2 scan0264 | |
| Instructing on the new drawings and List of Parts (LOP) for an oil filler on a 20/25 HP chassis. | 5th Oct 1933 | Box 103 \ 2 scan0265 | |
| Standardisation of a larger oil filler for the crankcase on the 20/25 HP chassis. | 14th Jul 1933 | Box 103 \ 2 scan0266 | |
| Form outlining the implementation details for the standardisation of a new chassis part. | 27th Apr 1934 | Box 103 \ 2 scan0267 | |
| Standardisation of parts for a side oil drain in the engine sump. | 27th Apr 1934 | Box 103 \ 2 scan0268 | |
| Estimated cost for extra jigs, tools and equipment required for the 'F' series. | 5th Jun 1934 | Box 103 \ 2 scan0269 | |
| Deletion of two holes in the 25-HP bottom half crankcase following a 10,000-mile test. | 7th Sep 1934 | Box 103 \ 2 scan0270 | |
| Confirmation of a modification to a C.14 Unit front lower half baffle, including a diagram. | 17th Sep 1934 | Box 103 \ 2 scan0271 | |
| Standardisation of parts document for a modified crankcase baffle to prevent loss of oil pressure when braking. | 18th Sep 1934 | Box 103 \ 2 scan0272 | |
| Cost reduction on the Bentley 25/30 HP chassis by modifying the crankcase. | 21th Feb 1936 | Box 103 \ 2 scan0273 | |
| Instruction for production of new intermediate main bearings for the 25/30 HP chassis. | 21th Feb 1936 | Box 103 \ 2 scan0274 | |
| Unsatisfactory crankcase rear oil seal on the 25 HP & Bentley and a proposal for a new design. | 27th Feb 1936 | Box 103 \ 2 scan0275 | |
| Experimental camshaft modification to improve the slow running of the 25/30 unit. | 16th Sep 1936 | Box 103 \ 2 scan0276 | |
| Crankcase depression tests comparing a 25.HP model with a Chevrolet. | 5th Feb 1937 | Box 103 \ 2 scan0277 | |
| Test report on zinc alloy crankshaft journal and big-end bearings. | 26th Mar 1930 | Box 103 \ 3 scan0001 | |
| Engine bearing failure due to zinc-alloy growth at high RPM and a proposed solution. | 26th Jan 1931 | Box 103 \ 3 scan0002 | |
| | | | |
