| Description | Date | Identifier | |
| Letter to H.M. Hobson Components Ltd. regarding issues with Esso Ethyl fuel used in an endurance test, describing its gummy state and black deposits. | 28th Jan 1939 | Box 149 \ 3 scan0014 | |
| Letter to the S.U. Carburetter Co. Ltd. regarding modifications to an HP pump, focusing on spindle diameter limits and a new guide bush. | 31th Jan 1939 | Box 149 \ 3 scan0015 | |
| Standardisation of petrol pumps for the Phantom III and Wraith C series models. | 4th Feb 1939 | Box 149 \ 3 scan0016 | |
| Letter to The Avon India Rubber Co. Ltd. regarding a perished petrol pipe. | 7th Feb 1939 | Box 149 \ 3 scan0017 | |
| Letter from H.M. Hobson Ltd. arranging a meeting to discuss a failed pump and a laboratory report. | 8th Feb 1939 | Box 149 \ 3 scan0018 | |
| Letter to a supplier regarding sticking petrol gauge tank units, possibly caused by French fuel. | 8th Feb 1939 | Box 149 \ 3 scan0019 | |
| Letter from Avon India Rubber Co. Ltd. acknowledging receipt of a petrol pipe sample for testing. | 9th Feb 1939 | Box 149 \ 3 scan0020 | |
| Letter from S. Smith & Sons regarding tests on tank unit bearings and their resistance to stickiness in fuel. | 10th Feb 1939 | Box 149 \ 3 scan0021 | |
| Letter from S. Smith & Sons regarding trouble with rubber connections in a tank and a sticking bearing. | 11th Feb 1939 | Box 149 \ 3 scan0022 | |
| Letter to S.U. Carburetter Co. Ltd. about endurance testing on petrol pumps, focusing on spark quenching and contact point wear. | 11th Feb 1939 | Box 149 \ 3 scan0023 | |
| Letter concerning test results for a standard HP pump and urging the delivery of cast iron HP pumps on order. | 11th Feb 1939 | Box 149 \ 3 scan0024 | |
| Comparison of petrol tank specifications for B.5 and B.50 models. | 17th Feb 1939 | Box 149 \ 3 scan0025 | |
| Letter to S.Smith & Sons Ltd. regarding graphite bearings, fuel tests, and potential design modifications. | 17th Feb 1939 | Box 149 \ 3 scan0026 | |
| Letter to S.U. Carburetter Co. regarding pump endurance testing, wear analysis, and enclosing oscillogram prints. | 18th Feb 1939 | Box 149 \ 3 scan0027 | |
| Report discussing optimum electrical resistance and its effect on sparking and voltage in a non-inductive circuit. | 21th Feb 1939 | Box 149 \ 3 scan0028 | |
| Letter from S. Smith & Sons concerning a complaint about Petrol Tank Attachment failures on the 'Wraith' model. | 21th Feb 1939 | Box 149 \ 3 scan0029 | |
| Continuation page of a letter from S. Smith & Sons to W.A. Robotham Esq. | 21th Feb 1939 | Box 149 \ 3 scan0030 | |
| The standardisation of HP petrol pumps for the Phantom III, making them interchangeable with C series Wraith pumps. | 21th Feb 1939 | Box 149 \ 3 scan0031 | |
| Request for a sample of synthetic rubber tubing for testing with various fuels. | 22th Feb 1939 | Box 149 \ 3 scan0032 | |
| Analysis of petrol pump current and voltage conditions using oscillograms, comparing different coil housings and a patented modification. | 24th Feb 1939 | Box 149 \ 3 scan0033 | |
| Performance characteristics of a low-resistance electrical circuit, focusing on current, voltage, and component wear. | 24th Feb 1939 | Box 149 \ 3 scan0034 | |
| Oscillogram curves for S.U. high-pressure petrol pumps comparing performance with and without resistance. | 10th Feb 1934 | Box 149 \ 3 scan0035 | |
| Blueprint of circuit diagrams for main and auxiliary contacts. | 27th Feb 1939 | Box 149 \ 3 scan0036 | |
| Letter from The Avon India Rubber Co. Ltd. confirming they will make a length of synthetic rubber tubing. | 27th Feb 1939 | Box 149 \ 3 scan0037 | |
| Letter to H.M. Hobson Components Ltd. regarding the dispatch of an 18-gallon petrol tank. | 1st Mar 1939 | Box 149 \ 3 scan0038 | |
| Letter from H.M. Hobson Components Ltd. regarding the receipt of an 18-gallon petrol tank and the fitting of a Hobson K-S Telegage. | 3rd Mar 1939 | Box 149 \ 3 scan0039 | |
| Letter from a rubber supplier regarding two samples of tubing being produced. | 8th Mar 1939 | Box 149 \ 3 scan0040 | |
| The development and standardisation of a Tufnol guide bush for the High-Pressure S.U. Petrol Pump. | 11th Mar 1939 | Box 149 \ 3 scan0041 | |
| Letter from S. Smith & Sons regarding failures of petrol gauge tank attachments on the 'Wraith' chassis. | 20th Mar 1939 | Box 149 \ 3 scan0042 | |
| Continuation letter from S. Smith & Sons to W.A. Robotham confirming reimbursement for conversion work on a cost basis. | 20th Mar 1939 | Box 149 \ 3 scan0043 | |
| Preference for how an order of tubing should be divided. | 20th Mar 1939 | Box 149 \ 3 scan0044 | |
| Repair, testing, and stocking of various S.U. fuel pumps. | 24th Mar 1939 | Box 149 \ 3 scan0045 | |
| Examination report on faulty HP SU petrol pumps, listing faults against chassis and pump numbers. | 25th Mar 1939 | Box 149 \ 3 scan0046 | |
| Pump failures attributed to careless assembly and procedural errors. | 25th Mar 1939 | Box 149 \ 3 scan0047 | |
| Letter from S. Smith & Sons regarding the repair of a tank attachment from chassis WRB-23 and the supply of a free replacement unit. | 27th Mar 1939 | Box 149 \ 3 scan0048 | |
| Letter from S. Smith & Sons concerning a suggested modification to petrol gauge tank attachments. | 27th Mar 1939 | Box 149 \ 3 scan0049 | |
| Dispute with S.U. Company over the warranty and repair of petrol pumps. | 28th Mar 1939 | Box 149 \ 3 scan0050 | |
| The cost and process of repairing pumps, including a proposal for a flat rate repair charge. | 28th Mar 1939 | Box 149 \ 3 scan0051 | |
| Requesting authority to arrange repair work and for the order office to obtain prices. | 28th Mar 1939 | Box 149 \ 3 scan0052 | |
| Letter from The S.U. Carburetter Co. Ltd. querying specifications for an order of 350 Petrol Pump Assemblies. | 28th Mar 1939 | Box 149 \ 3 scan0053 | |
| Letter from The S.U. Carburetter Co. Ltd. requesting a blueprint assembly for a pump. | 30th Mar 1939 | Box 149 \ 3 scan0054 | |
| Letter to the S.U. Carburetter Co. Ltd. specifying requirements for an order of 350 pumps. | 30th Mar 1939 | Box 149 \ 3 scan0055 | |
| Requesting disposal instructions for rejected petrol pump coil housings. | 6th Apr 1939 | Box 149 \ 3 scan0056 | |
| Rejected petrol pump parts, specifically coil housings, awaiting disposal instructions. | 14th Apr 1939 | Box 149 \ 3 scan0057 | |
| Letter to S.U. Carburetter Co. Ltd. regarding olive joint fittings for petrol pumps. | 19th Apr 1939 | Box 149 \ 3 scan0058 | |
| Petrol pump failures, their causes, and repair procedures. | 26th Apr 1939 | Box 149 \ 3 scan0059 | |
| Repair and replacement specifications for petrol pump parts. | 2nd May 1939 | Box 149 \ 3 scan0060 | |
| Correspondence page from 'The Autocar' magazine discussing various motoring topics. | 5th May 1939 | Box 149 \ 3 scan0061 | |
| Page from 'The Autocar' magazine, featuring correspondence on topics including insurance, tyres, road quality, and a parliamentary bill on mountain access. | 5th May 1939 | Box 149 \ 3 scan0062 | |
| The condition of an S.U. Petrol Pump after a 50,300-mile test. | 15th May 1939 | Box 149 \ 3 scan0063 | |
| Inspection report on a pump, water excluding sleeves, and other general components after mileage. | 15th May 1939 | Box 149 \ 3 scan0064 | |
| Scheme to repair petrol pumps at the Works, detailing the required parts and stock levels. | 16th May 1939 | Box 149 \ 3 scan0065 | |
| List of percentage requirements for pump repair parts and an update on a modified pump. | 16th May 1939 | Box 149 \ 3 scan0066 | |
| Comparative parts list table for components across various Bentley and Rolls-Royce car models. | 16th May 1939 | Box 149 \ 3 scan0067 | |
| Parts compatibility list for various models including Bentley, 25/30, High Pressure Wraith P.III, and Modified HP Bentley V. | 16th May 1939 | Box 149 \ 3 scan0068 | |
| Return of S.U. Neoprene Diaphragm Assemblies due to the supplied material not being to specification. | 20th May 1939 | Box 149 \ 3 scan0069 | |
| Letter from S.U. Carburetter Co. Ltd. regarding an incorrect diaphragm supplied for pump sets on order 846246. | 23th May 1939 | Box 149 \ 3 scan0070 | |
| Letter to The S.U. Co. Ltd. requesting a replacement for a faulty Cast Iron HP petrol pump. | 2nd Jun 1939 | Box 149 \ 3 scan0071 | |
| Letter from S.U. Carburetter Co. Ltd. advising on the return of a cast iron HP petrol pump. | 7th Jun 1939 | Box 149 \ 3 scan0072 | |
| Issues and performance testing of petrol pump diaphragm assemblies. | 10th Jun 1939 | Box 149 \ 3 scan0073 | |
| The resistance of Neoprene to Discol and the conditions for accepting Neoprene assemblies. | 10th Jun 1939 | Box 149 \ 3 scan0074 | |
| Letter to The S.U. Co. Ltd. regarding an urgent order for diaphragm assemblies and incorrect packing ring dimensions. | 10th Jun 1939 | Box 149 \ 3 scan0075 | |
| Letter to The S.U. Co. Ltd. concerning revised specifications for pumps PP.16.L and PP.19.L. | 15th Jun 1939 | Box 149 \ 3 scan0076 | |
| Instruction that petrol pump repairs will be carried out at the Works in future. | 26th Jun 1939 | Box 149 \ 3 scan0077 | |
| Material changes for petrol pump diaphragms, specifically a switch to Neoprene Fabric. | 27th Jun 1939 | Box 149 \ 3 scan0078 | |
| Letter from The S.U. Carburetter Co. Ltd. concerning the supply of diaphragm assemblies for high-pressure pumps. | 28th Jun 1939 | Box 149 \ 3 scan0079 | |
| Letter from The S.U. Carburetter Co. Ltd. concerning two experimental pumps and an investigation into water hammer noise. | 3rd Jul 1939 | Box 149 \ 3 scan0080 | |
| Official order for Neoprene and white diaphragms. | 4th Jul 1939 | Box 149 \ 3 scan0081 | |
| Letter from S.U. Carburetter Co. Ltd. enclosing pump specifications and detailing a change in diaphragm assembly. | 6th Jul 1939 | Box 149 \ 3 scan0082 | |
| Proposal to change petrol pumps to a cast iron coil housing and neoprene diaphragm design for the next 100 Wraith chassis. | 6th Jul 1939 | Box 149 \ 3 scan0083 | |
| Issue with the petrol tank's filling vent causing regurgitation and partial filling. | 6th Jul 1939 | Box 149 \ 3 scan0084 | |
| Letter to The S.U. Co. Ltd. altering the specification for high-pressure diaphragms to be made of 3 layers of .030' Neoprene fabric. | 6th Jul 1939 | Box 149 \ 3 scan0085 | |
| Replacement of oil silk diaphragms with Neoprene diaphragms in petrol pumps. | 6th Jul 1939 | Box 149 \ 3 scan0086 | |
| Querying the replacement policy for S.U. Petrol Pumps, specifically whether older types should be replaced irrespective of a complaint. | 10th Jul 1939 | Box 149 \ 3 scan0087 | |
| Standardization of petrol tank sizes and the considerations for different models and markets. | 11th Jul 1939 | Box 149 \ 3 scan0088 | |
| Clarifying the policy on fitting Neoprene diaphragms to new pumps and those returned for repair. | 12th Jul 1939 | Box 149 \ 3 scan0089 | |
| Requesting the return of a petrol filler head sample to Wilmot Breedon Ltd. | 14th Jul 1939 | Box 149 \ 3 scan0090 | |
| Request to dispatch a petrol gauge unit to S. Smith & Sons for the attention of Mr. Russell. | 15th Jul 1939 | Box 149 \ 3 scan0091 | |
| Letter to a supplier regarding the return and replacement of a flush-fitting filler sample due to design issues. | 15th Jul 1939 | Box 149 \ 3 scan0092 | |
| Letter from the Experimental Department requesting particulars of mechanical pumps from AC Sphinx Sparking Plug Co. Ltd. | 17th Jul 1939 | Box 149 \ 3 scan0093 | |
| Letter from S.U. Carburetter Co. Ltd. regarding a new unassembled high-pressure pump for a Bentley. | 19th Jul 1939 | Box 149 \ 3 scan0094 | |
| Letter to S. Smith & Sons Ltd. regarding a faulty single wire type petrol gauge returned for inspection. | 21th Jul 1939 | Box 149 \ 3 scan0095 | |
| Letter to S.U. Carburetter Co. Ltd. regarding a satisfactory petrol pump assembly and a query about a change in its Neoprene diaphragms. | 22th Jul 1939 | Box 149 \ 3 scan0096 | |
| Letter from S.U. Carburetter Co. confirming an order for 200 new pumps and addressing a query about fibre packing. | 24th Jul 1939 | Box 149 \ 3 scan0097 | |
| Letter to S.U. Carburetter Co. Ltd. regarding a query on a packing piece for an armature assembly. | 26th Jul 1939 | Box 149 \ 3 scan0098 | |
| The issue of an official order for one petrol pump. | 28th Jul 1939 | Box 149 \ 3 scan0099 | |
| Difficulties with the 10.B.V. petrol filler due to incorrect vent pipe fitting. | 22th Mar 1939 | Box 149 \ 3 scan0100 | |
| Making the 22-gallon petrol tank standard for the Bentley V Chassis. | 1st Sep 1939 | Box 149 \ 3 scan0101 | |
| Experimenting with aluminium petrol tanks for cars and seeking recommendations for manufacturers. | 9th Jan 1940 | Box 149 \ 3 scan0102 | |
| Request to investigate troubles with Neoprene diaphragm petrol pumps. | 11th Jan 1940 | Box 149 \ 3 scan0103 | |
| Letter to S.U. Carburetter Co. Ltd. regarding a complaint about expanding Neoprene Fabric diaphragms. | 12th Jan 1940 | Box 149 \ 3 scan0104 | |
| Letter from S.U. Carburetter Co. Ltd. regarding Neoprene diaphragm failures and swelling in pumps. | 13th Jan 1940 | Box 149 \ 3 scan0105 | |
| Continuation page of a letter from The S.U. Carburetter Co. Ltd. concerning diaphragm issues due to a possible change in fuel. | 17th Jan 1940 | Box 149 \ 3 scan0106 | |
| Letter to The S.U. Carburetter Co. Ltd. regarding the supply of Neoprene diaphragms and red washers. | 17th Jan 1940 | Box 149 \ 3 scan0107 | |
| Recommending potential suppliers for petrol tanks. | 19th Jan 1940 | Box 149 \ 3 scan0108 | |
| Confirming design changes for a petrol tank, including material thickness and component removal. | 8th Feb 1940 | Box 149 \ 3 scan0109 | |
| Letter from Fleming's Hotel regarding proposals for direct injection systems. | 11th Jan 1940 | Box 149 \ 3 scan0110 | |
| Letter discussing challenges in developing direct injection technology, including patents and third-party agreements. | 11th Jan 1940 | Box 149 \ 3 scan0111 | |
| Letter on Fleming's Hotel stationery discussing a business offer from The Rover Co and negotiations with Morris Motors. | 11th Jan 1940 | Box 149 \ 3 scan0112 | |
| Letter discussing fuel injection prospects, pump and control gear design, and placing orders for parts. | 11th Jan 1940 | Box 149 \ 3 scan0113 | |
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