| Description | Date | Identifier | |
| Design alterations for the Wraith III and Bentley 111 connecting rod bush without shims. | 8th Feb 1938 | Box 132 \ 2 scan0239 | |
| Letter to Hughes Johnson Stampings Ltd regarding considerable errors found on connecting rods, E.60811/12. | 17th Aug 1937 | Box 132 \ 2 scan0240 | |
| Inspector's report on errors found in a proof forging of a connecting rod and cap. | 12th Aug 1937 | Box 132 \ 2 scan0241 | |
| Production issues and endurance testing of connecting rod little end bushes. | 21th Apr 1938 | Box 132 \ 2 scan0242 | |
| Assembly, clearance, and production issues of connecting rod small end bushes. | 26th Apr 1938 | Box 132 \ 2 scan0243 | |
| Connecting rod bearings for the Phantom III and Wraith models. | 15th Feb 1938 | Box 132 \ 2 scan0244 | |
| Specifications and value of experimenting with forged to size connecting rods. | 25th Mar 1939 | Box 132 \ 2 scan0245 | |
| Letter to arrange a meeting to discuss forged size rods. | 5th Apr 1939 | Box 132 \ 2 scan0246 | |
| Letter from Hardy Spicer & Co. Limited to Mr. Robotham arranging a meeting. | 6th Apr 1939 | Box 132 \ 2 scan0247 | |
| Letter confirming a visit to discuss dynamometer-tested slip joints and accepting a luncheon invitation. | 12th Apr 1939 | Box 132 \ 2 scan0248 | |
| Letter from Hardy Spicer & Co. Ltd regarding a revised print for a Con-rod Forging, omitting the test piece. | 20th Apr 1939 | Box 132 \ 2 scan0249 | |
| Letter to Hardy Spicer & Co., Ltd. confirming a satisfactory test piece from a connecting rod. | 28th Apr 1939 | Box 132 \ 2 scan0250 | |
| Agreement to delete test pieces from connecting rods produced by Hardy Spicer's. | 28th Apr 1939 | Box 132 \ 2 scan0251 | |
| Drawing for a coined connecting rod, noting the deletion of a test piece and requesting a copy for the Works. | 28th Apr 1939 | Box 132 \ 2 scan0252 | |
| The production of a forging drawing for a Bentley 5 connecting rod. | 1st May 1939 | Box 132 \ 2 scan0253 | |
| Requesting an estimate of savings from using un-machined connecting rods and a crankshaft with integral balance weights. | 26th May 1939 | Box 132 \ 2 scan0254 | |
| Letter from The S.U. Carburetter Co. Ltd. specifying the distance between the centres of 16 HP Con Rods. | 23th Oct 1939 | Box 132 \ 2 scan0255 | |
| Copy of a letter from Skinner concerning connecting rods. | 24th Oct 1939 | Box 132 \ 2 scan0256 | |
| Letter from The S.U. Carburetter Co. Ltd. regarding the centre distance of the 16 HP con rods. | 23th Oct 1939 | Box 132 \ 2 scan0257 | |
| Letter from Hardy Spicer regarding delays with new forging machines and difficulty procuring steel for Connecting Rods. | 26th Oct 1939 | Box 132 \ 2 scan0258 | |
| Letter to Hardy Spicer & Co. Ltd. regarding the provision of steel for a Con Rod experiment. | 27th Oct 1939 | Box 132 \ 2 scan0259 | |
| Drawings and production of connecting rods and associated parts. | 29th Dec 1939 | Box 132 \ 2 scan0260 | |
| Confirming a conversation about getting forgings from dies for B.V. connecting rods, with plans to re-sink the dies for 4-cylinder rods. | 22th Apr 1940 | Box 132 \ 2 scan0261 | |
| Production delays and tooling for connecting rods from supplier Hardy Spicers. | 24th Apr 1940 | Box 132 \ 2 scan0262 | |
| Suggestion to produce dies for forging size B.40 connecting rods. | 27th Apr 1940 | Box 132 \ 2 scan0263 | |
| Alteration note for a connecting rod, detailing the deletion of a dimension and the addition of a clarifying note. | 16th May 1940 | Box 132 \ 2 scan0264 | |
| Letter from Hardy Spicer & Co. discussing connecting rod forgings, including die life and tolerances. | 17th Jun 1940 | Box 132 \ 2 scan0265 | |
| Connecting rod big end lubrication. | 27th Jun 1941 | Box 132 \ 2 scan0266 | |
| Technical memorandum detailing the evolution and changes made to the connecting rod big end lubrication system. | 24th Jun 1941 | Box 132 \ 2 scan0267 | |
| Lubrication troubles and modifications for the Bentley engine. | 24th Jun 1941 | Box 132 \ 2 scan0268 | |
| The first engine drawing for the Bensport J.1 car, detailing drawing LeC.3256. | 29th Oct 1932 | Box 132 \ 3 scan0001 | |
| Design specifications for the Bensport J.3 engine oil tank. | 11th Nov 1932 | Box 132 \ 3 scan0002 | |
| Recommendations for oil tank design, including temperature management, cooling baffles, and drainage. | 11th Nov 1932 | Box 132 \ 3 scan0003 | |
| The venting of the Bensport J.1. oil tank to the crankcase. | 16th Nov 1932 | Box 132 \ 3 scan0004 | |
| Dynamo and crankcase modifications for the Bensport and 20/25 HP engines. | 10th Feb 1933 | Box 132 \ 3 scan0005 | |
| Bensport Series 1 modification to raise the starter motor for improved ground clearance after an issue on an experimental car. | 13th Mar 1933 | Box 132 \ 3 scan0006 | |
| Engine fumes in a Bensport Car and a proposed solution involving a new breather system. | 8th May 1933 | Box 132 \ 3 scan0007 | |
| Modifying the Bensport Oil Pipe, changing its shape, material, and adding a securing clip. | 8th May 1933 | Box 132 \ 3 scan0008 | |
| Modification for the Bentley bottom half crankcase to correct an issue where the brake rope fouls the silencer tie. | 31th May 1933 | Box 132 \ 3 scan0009 | |
| Breakage of a Bentley crankcase central main bearing and proposing a design modification. | 25th Oct 1933 | Box 132 \ 3 scan0010 | |
| Modifications to the Bentley Crankcase following an engine failure. | 26th Oct 1933 | Box 132 \ 3 scan0011 | |
| Modifications to Bentley crankcases, including a pattern alteration and the introduction of bolts for the centre bearing. | 27th Oct 1933 | Box 132 \ 3 scan0012 | |
| Modified positions of the filling plug and dip stick for a Bentley. | 13th Nov 1933 | Box 132 \ 3 scan0013 | |
| Crankcase modification to prevent oil starvation under braking. | 17th Nov 1933 | Box 132 \ 3 scan0014 | |
| Proposed modification to increase the Bentley's ground clearance after a customer's concern. | 21th Nov 1933 | Box 132 \ 3 scan0015 | |
| Diagram showing a modified sump plate and oil drain plug for a Bentley & 25HP to increase ground clearance. | 20th Nov 1933 | Box 132 \ 3 scan0016 | |
| Drawing LeC.3727, detailing a modification to the Bentley drain plug for improved ground clearance. | 11th Dec 1933 | Box 132 \ 3 scan0017 | |
| The modification of the Bentley sump drain plug to improve ground clearance. | 14th Dec 1933 | Box 132 \ 3 scan0018 | |
| Standardisation of a modified crankcase baffle to prevent loss of oil pressure during braking. | 20th Dec 1933 | Box 132 \ 3 scan0019 | |
| Requesting the re-build of a C.13 Unit with magnesium castings for testing on the Test Bed. | 7th Feb 1934 | Box 132 \ 3 scan0020 | |
| Test report on a Bentley magnesium top half crankcase failure and potential for redesign. | 15th May 1934 | Box 132 \ 3 scan0021 | |
| Photograph of a multi-cylinder engine crankcase with the main bearing caps installed. | 15th May 1934 | Box 132 \ 3 scan0022 | |
| Top-down photograph of an engine block's lower half, detailing the main bearing caps. | 11th Jun 1934 | Box 132 \ 3 scan0023 | |
| Modifications required for a Bentley 4-Bearing Crankcase to be cast in magnesium. | 11th Jun 1934 | Box 132 \ 3 scan0024 | |
| Requesting an immediate order for a magnesium lower half part for future use. | 5th Nov 1934 | Box 132 \ 3 scan0025 | |
| Request to make up a Spectre bottom half to address the loss of oil pressure during cornering and braking. | 19th Nov 1934 | Box 132 \ 3 scan0026 | |
| Potential use of Magnesium instead of R.R. Metal for a Bentley Bottom Half Crankcase to save weight. | 5th Dec 1934 | Box 132 \ 3 scan0027 | |
| Letter from High Duty Alloys Ltd. regarding the manufacturing feasibility of a Bentley Bottom Half Crankcase in Magnesium. | 4th Dec 1934 | Box 132 \ 3 scan0028 | |
| Reducing the thickness of the Bentley bottom half crankcase to save weight. | 7th Dec 1934 | Box 132 \ 3 scan0029 | |
| Request for a modified crankcase breather pipe for a Bentley vehicle. | 8th Apr 1935 | Box 132 \ 3 scan0030 | |
| Internal memorandum concerning a Bentley Crankcase Breather Pipe. | 25th Apr 1935 | Box 132 \ 3 scan0031 | |
| Test report on oil delivery to bearings for a Bentley Crankcase Oil Tube and bearings arrangement. | 15th Jul 1935 | Box 132 \ 3 scan0032 | |
| Test results for increased capacity helical gear Bentley oil pumps showing delivery rates and initial relief pressures. | 18th Jan 1935 | Box 132 \ 3 scan0033 | |
| Test log for a B-1 unit crankcase, detailing running hours, dates, test outcomes and failures. | 10th Aug 1935 | Box 132 \ 3 scan0034 | |
| Laboratory findings on the grain size of a bearing from a cracked Large Bore Bentley crankcase. | 13th Aug 1935 | Box 132 \ 3 scan0035 | |
| The cost and supply of magnesium metal bottom half crankcase castings for the Spectre Chassis. | 15th Aug 1935 | Box 132 \ 3 scan0036 | |
| Modification to the Spectre Crankcase rear flange to use set-screws instead of studs. | 6th Sep 1935 | Box 132 \ 3 scan0037 | |
| Listing new Lists of Parts (L.O.P.) and details for the Large Bore Bentley crankcase and bearings. | 28th Nov 1935 | Box 132 \ 3 scan0038 | |
| New and cancelled blueprints for the Bentley Chassis crankcase and bearings (Large Bore). | 10th Jan 1936 | Box 132 \ 3 scan0039 | |
| Instructions for a new experimental Sump Drain Plug for a Large Bore Bentley, including a request for destructive testing. | 16th Jan 1936 | Box 132 \ 3 scan0040 | |
| Directive to delete a machining operation on the crankcase bosses for cost reduction on Bentley and 25-30 HP chassis. | 25th Feb 1936 | Box 132 \ 3 scan0041 | |
| Unsatisfactory rear oil seal on the 25 HP & Bentley, proposing an experimental replacement. | 27th Feb 1936 | Box 132 \ 3 scan0042 | |
| Blueprints for a new crankcase drawing for an O.H.C. Car Engine S.C. Unit. | 4th Mar 1936 | Box 132 \ 3 scan0043 | |
| Request to alter the crankcase drawing for a Bentley engine to suit a large bore engine. | 17th Mar 1936 | Box 132 \ 3 scan0044 | |
| Modifications to a cast-iron crankcase and the scrapping of existing aluminium versions. | 17th Mar 1936 | Box 132 \ 3 scan0045 | |
| Request to the Pattern Shop to stop work on the pattern for the EX.20400 cylinder head. | 19th Mar 1936 | Box 132 \ 3 scan0046 | |
| Component changes for the Bentley II Chassis crankcase and bearings. | 26th Mar 1936 | Box 132 \ 3 scan0047 | |
| Instruction sheet detailing part replacements and modifications for crankshaft and connecting rod sections for an experiment. | 26th Mar 1936 | Box 132 \ 3 scan0048 | |
| Instruction regarding an omitted rear bearing cap for the Bentley II chassis crankcase. | 2nd Apr 1936 | Box 132 \ 3 scan0049 | |
| List of parts required for an experiment on the Bentley II Chassis Crankcase, Bearings, and Clutch Operating Mechanism. | 8th Apr 1936 | Box 132 \ 3 scan0050 | |
| Design and testing of an oil baffle box for the Phantom III crankcase breather. | 9th Apr 1936 | Box 132 \ 3 scan0051 | |
| New crankcase breather scheme (LeC.5067) for the Phantom III, designed to reduce oil loss at high speeds. | 22th Apr 1936 | Box 132 \ 3 scan0052 | |
| Modified crankcase breather for the Phantom III to address over-oiling issues at high RPM. | 23th Apr 1936 | Box 132 \ 3 scan0053 | |
| The testing of a newly designed Phantom III crankcase breather to solve an oil escape issue. | 16th Jun 1936 | Box 132 \ 3 scan0054 | |
| Cost-saving proposal for the Phantom III crankcase by changing the oil tray from aluminium to mild steel. | 9th Oct 1936 | Box 132 \ 3 scan0055 | |
| Investigation into cost reduction for the Phantom III lower half crankcase by modifying the oil flap valves. | 15th Oct 1936 | Box 132 \ 3 scan0056 | |
| Cost-saving modification to the Phantom III lower half crankcase and a request for testing. | 27th Oct 1936 | Box 132 \ 3 scan0057 | |
| Simplified oil flaps designed to cheapen production. | 2nd Nov 1936 | Box 132 \ 3 scan0058 | |
| The results of tests on a modified Phantom III lower half crankcase with altered oil flap valves. | 2nd Nov 1936 | Box 132 \ 3 scan0059 | |
| Urging the detailing of the lower half LeC.5345 to proceed with a 10,000-mile test. | 3rd Nov 1936 | Box 132 \ 3 scan0060 | |
| Letter to Cadillac requesting information on crankshaft dampers for 12-cylinder engines. | 10th Nov 1936 | Box 132 \ 3 scan0061 | |
| Request for a weight comparison of machined crankcase top halves from an external supplier against in-house castings. | 26th Nov 1936 | Box 132 \ 3 scan0062 | |
| Crankcase after a crack test, detailing nine cracks found and recommending repair. | 24th Dec 1936 | Box 132 \ 3 scan0063 | |
| Blueprint showing the results of a crack test on a B17 unit crankcase (top half). | 22th Dec 1936 | Box 132 \ 3 scan0064 | |
| Heat treatment and stress-releasing instructions for Hykro crankshafts for the Phantom III Chassis and Bentley. | 11th Dec 1936 | Box 132 \ 3 scan0065 | |
| Confirming the modification of the crankcase lower half for the Wraith model. | 11th Dec 1936 | Box 132 \ 3 scan0066 | |
| Bad crack found in the magnesium lower half crankcase of a Phantom III No. 11 Unit, causing oil leaks. | 26th Feb 1937 | Box 132 \ 3 scan0067 | |
| Blueprint detailing a cracked magnesium lower crankcase half, showing inverted and plan views with analysis. | 23th Feb 1937 | Box 132 \ 3 scan0068 | |
| Production efficiency report detailing casting times and weights for various components. | 5th Aug 1937 | Box 132 \ 3 scan0069 | |
| Cost analysis and manufacturing review of the Phantom III crankcase. | 9th Aug 1937 | Box 132 \ 3 scan0070 | |
| | | | |
