| Description | Date | Identifier | |
| Remarks on an attached letter concerning a new type of filter from Engineer Admiral Rattey. | 21th Jul 1930 | Box 135 \ 3 scan0017 | |
| Follow-up letter from Birt Hudson regarding an interview and correspondence about 'Auto-Klean Strainers'. | 21th Jul 1930 | Box 135 \ 3 scan0018 | |
| Letter to Engineer Admiral Rattey requesting a description of an oil filter. | 22th Jul 1930 | Box 135 \ 3 scan0019 | |
| The modification of a P.2. carburetter to fit an air maze gauze screen for cars used in Australia and India. | 9th Sep 1930 | Box 135 \ 3 scan0020 | |
| Supply and assembly arrangement for Auto Klean Strainers. | 18th Sep 1930 | Box 135 \ 3 scan0021 | |
| On the performance of two tested Autokleen filters with spring loaded glands regarding oil leaks. | 10th Oct 1930 | Box 135 \ 3 scan0022 | |
| Follow-up letter from Benton & Stone Ltd. regarding a test on a porous pot filter sample. | 27th Oct 1930 | Box 135 \ 3 scan0023 | |
| Letter to Messrs. Benton & Stone regarding the performance and price comparison of a porous pot filter. | 3rd Nov 1930 | Box 135 \ 3 scan0024 | |
| Letter from Benton & Stone Ltd. regarding the performance and cost of a Porous Pot Filter. | 5th Nov 1930 | Box 135 \ 3 scan0025 | |
| Standardisation report on replacing the scroll clutch with a ratchet freewheel in the Auto Kleen Filter. | 25th Aug 1930 | Box 135 \ 3 scan0026 | |
| The company's position regarding Metafilters (1929) Ltd. | 4th Dec 1930 | Box 135 \ 3 scan0027 | |
| Metafilters (1929) Ltd. seeking feedback on their oil filters under test. | 3rd Dec 1930 | Box 135 \ 3 scan0028 | |
| Blueprint of a Sump Oil Filter, showing various sections and components. | 21th Jan 1931 | Box 135 \ 3 scan0029 | |
| Test report on the Auto Klean Oil Filter E.81173, detailing pressure readings for the bypass system. | 21th Jan 1931 | Box 135 \ 3 scan0030 | |
| Instruction to fit a standard Enots petrol filler to car 14-EX and remove the carburetter filter. | 6th Feb 1931 | Box 135 \ 3 scan0031 | |
| Clearance of the spigot in the Autokleen filter, concluding no modifications are necessary. | 10th Feb 1931 | Box 135 \ 3 scan0032 | |
| Standardisation of chassis parts for the Enots Petrol Filter. | 14th Jan 1931 | Box 135 \ 3 scan0033 | |
| Standardisation report concerning new chassis parts, including costs and fitting details. | 12th Feb 1931 | Box 135 \ 3 scan0034 | |
| Telephone conversation about engine design specifications for oil flow, sump connections, and induction system. | 28th Oct 1931 | Box 135 \ 3 scan0035 | |
| Dissatisfaction with filters for the Bijur lubrication system and proposing testing of alternatives. | 18th Nov 1931 | Box 135 \ 3 scan0036 | |
| Promotional flyer for the 'Smith' air filter with silencer and warning whistle. | 18th Nov 1931 | Box 135 \ 3 scan0037 | |
| Descriptive document for the 'Smith' Air Filter with Silencer & Warning Whistle. | 19th Dec 1931 | Box 135 \ 3 scan0038 | |
| Attached letter and invoice for Smith carburetter air filters. | 19th Dec 1931 | Box 135 \ 3 scan0039 | |
| Letter to Frank Smith & Co. regarding AFN.3 type air filters, requesting an invoice and materials for further testing. | 19th Dec 1931 | Box 135 \ 3 scan0040 | |
| Letter from Frank Smith & Co. confirming the preparation of 8 rings/filter pads with specified dimensions. | 29th Dec 1931 | Box 135 \ 3 scan0041 | |
| Letter from Frank Smith & Co. regarding the supply, specification, and pricing of filter pads. | 31th Dec 1931 | Box 135 \ 3 scan0042 | |
| Letter to Frank Smith & Co. acknowledging receipt of their letter and 8 filter pads. | 1st Jan 1931 | Box 135 \ 3 scan0043 | |
| Requesting a test on a sample Tecalemit Oil Cleaner and providing its pressure drop specifications. | 2nd Mar 1932 | Box 135 \ 3 scan0044 | |
| Test report on a 'Tecalemit' oil filter performance with Motorine 'C' oil. | 21th Mar 1932 | Box 135 \ 3 scan0045 | |
| Test data tables for pressure, temperature, and flow rates with a relief spring. | 21th Mar 1932 | Box 135 \ 3 scan0046 | |
| Graph showing the performance of a 'Tecalemit' oil filter, plotting delivery through the relief valve against inlet pressure at different temperatures. | 17th Mar 1932 | Box 135 \ 3 scan0047 | |
| Blueprint for a Relief Valve for a Tecalemit Oil Filter. | 18th Mar 1932 | Box 135 \ 3 scan0048 | |
| Letter to Messrs. Benton & Stone Ltd. regarding modifications to petrol filters. | 12th Jul 1932 | Box 135 \ 3 scan0049 | |
| Blueprint showing a modification for a reduced capacity petrol filter. | 28th Jun 1932 | Box 135 \ 3 scan0050 | |
| Letter from Benton & Stone Ltd. to Mr. W. A. Robotham regarding a sample and modifications to a petrol filter design. | 14th Jul 1932 | Box 135 \ 3 scan0051 | |
| Letter from Benton & Stone Ltd. regarding a sample of a special Petrol Filter and its construction. | 15th Jul 1932 | Box 135 \ 3 scan0052 | |
| Comparative test results for a reduced volume Enot's petrol filter against a standard filter. | 8th Aug 1932 | Box 135 \ 3 scan0053 | |
| Comparison report on the performance of Tecalemit and Autoklean oil filters following a 10,000-mile test. | 14th Oct 1932 | Box 135 \ 3 scan0054 | |
| List of arguments against a specific filter, noting its cost and performance. | 14th Oct 1932 | Box 135 \ 3 scan0055 | |
| Seeking feedback on the performance of Tecalemit oil filters on Tank engines. | 3rd Apr 1933 | Box 135 \ 3 scan0056 | |
| Reducing an Enot's filter capacity to decrease the time for petrol to be drawn through a dry pipe, for use on the first Bentley. | 1st May 1933 | Box 135 \ 3 scan0057 | |
| Order of six reduced capacity Enots petrol filters from Benton & Stone Ltd. | 1st May 1933 | Box 135 \ 3 scan0058 | |
| Criticism of the nut on the Bentley petrol filter, proposing a butterfly nut as an improvement. | 4th Jul 1933 | Box 135 \ 3 scan0059 | |
| Instruction to supply a Tecalemit Oil Filter for a 20/25 HP Chassis, noting it is a standard fitting on W.O. Tank Engines. | 2nd Oct 1933 | Box 135 \ 3 scan0060 | |
| Letter from British Wire Products Limited regarding their B.W.P. Variable Level Oil Intake device. | 24th Aug 1934 | Box 135 \ 3 scan0061 | |
| Brochure for the B.W.P. Variable Level Oil Intake, explaining its principle for better lubrication. | 24th Aug 1934 | Box 135 \ 3 scan0062 | |
| Promotional and technical leaflet for the B.W.P. Variable Level Oil Intake system. | 4th Sep 1934 | Box 135 \ 3 scan0063 | |
| Letter to British Wire Products Ltd. suggesting dates for an interview. | 4th Sep 1934 | Box 135 \ 3 scan0064 | |
| Letter from British Wire Products Ltd regarding a meeting about the B.W.P. Variable Level Oil Intake. | 8th Sep 1934 | Box 135 \ 3 scan0065 | |
| Telegram arranging an appointment for Mr. Robotham from British Wire Products. | 17th Sep 1934 | Box 135 \ 3 scan0066 | |
| Short typed telegram arranging a visit. | 17th Sep 1934 | Box 135 \ 3 scan0067 | |
| Arranging a trial for a B.W.P. oil intake on a 20/25 HP crankcase. | 20th Sep 1934 | Box 135 \ 3 scan0068 | |
| Promotional brochure for the B.W.P. Variable Level Oil Intake, explaining its benefits for engine lubrication. | 20th Sep 1934 | Box 135 \ 3 scan0069 | |
| Leaflet explaining the benefits and operation of the B.W.P. Variable Level Oil Intake system. | 26th Sep 1934 | Box 135 \ 3 scan0070 | |
| Letter to British Wire Products Ltd. regarding an Oil Intake Assembly. | 26th Sep 1934 | Box 135 \ 3 scan0071 | |
| Letter from British Wire Products Limited regarding a standard intake assembly and forthcoming test reports for a variable intake. | 21th Sep 1934 | Box 135 \ 3 scan0072 | |
| Fitting of a Tecalemit filter to the 20/25 model engine. | 4th Oct 1934 | Box 135 \ 3 scan0073 | |
| Letter from British Wire Products Limited regarding test reports on a variable level oil intake. | 25th Oct 1934 | Box 135 \ 3 scan0074 | |
| Tests covering the operating characteristics of the B.W.P. variable level oil intake. | 25th Oct 1934 | Box 135 \ 3 scan0075 | |
| Oil pump test number 1, detailing conditions and results of oil and water levels in a sump. | 25th Oct 1934 | Box 135 \ 3 scan0076 | |
| Test report summary on oil suction line performance and water disturbance at different oil levels. | 25th Oct 1934 | Box 135 \ 3 scan0077 | |
| Description of a test simulating engine break-in to evaluate the effect of foreign particles and a specific B.W.P. suction device. | 25th Oct 1934 | Box 135 \ 3 scan0078 | |
| Oil pump test comparing a B.W.P. device with a conventional suction assembly, including procedures for taking multiple oil samples. | 25th Oct 1934 | Box 135 \ 3 scan0079 | |
| Analysis of oil samples taken under various engine operating conditions. | 25th Oct 1934 | Box 135 \ 3 scan0080 | |
| The superiority of the B.W.P. Variable Level Oil Intake device for reducing engine wear during the initial breaking-in period. | 25th Oct 1934 | Box 135 \ 3 scan0081 | |
| Report comparing a B.W.P. suction device against a conventional system to reduce abrasive material in engine oil. | 25th Oct 1934 | Box 135 \ 3 scan0082 | |
| Report page detailing Test No.4, focusing on car operation and the effect of surging oil on sediment in the oil sump. | 25th Oct 1934 | Box 135 \ 3 scan0083 | |
| Oil sump tests, detailing water content analysis after violent brake applications and the use of a B.W.P. device. | 25th Oct 1934 | Box 135 \ 3 scan0084 | |
| Analysis of an experiment observing water and sediment pick-up from an oil sump using motion pictures. | 25th Oct 1934 | Box 135 \ 3 scan0085 | |
| The superior performance of the B.W.P. oil delivery device over conventional systems and the nature of tests conducted. | 25th Oct 1934 | Box 135 \ 3 scan0086 | |
| Comparison of oil temperature and pressure readings between a standard and a B.W.P. variable level oil intake device. | 25th Oct 1934 | Box 135 \ 3 scan0087 | |
| Oil pressure and temperature tests comparing different oil sump suction devices. | 25th Oct 1934 | Box 135 \ 3 scan0088 | |
| Comparison of oil pressure test results using a conventional suction device versus a B.W.P. device. | 25th Oct 1934 | Box 135 \ 3 scan0089 | |
| The benefits of a B.W.P. Float device for engine lubrication, oil pressure, and reducing deterioration. | 25th Oct 1934 | Box 135 \ 3 scan0090 | |
| Test report on the relative temperatures of oil at various depths in the sump under actual road conditions. | 18th Aug 1929 | Box 135 \ 3 scan0091 | |
| Oil temperature test report for a 1929 Chevrolet, comparing the standard system with a 'B.P.W.' installation. | 18th Aug 1929 | Box 135 \ 3 scan0092 | |
| Report comparing a B.W.P. lubrication suction device against a standard Chevrolet system, focusing on oil temperature and winter performance. | 18th Aug 1929 | Box 135 \ 3 scan0093 | |
| The benefits of a new lubrication device for internal combustion engines to improve reliability and reduce costs. | 9th Sep 1929 | Box 135 \ 3 scan0094 | |
| Laboratory report on the analysis of an oil sample from the Detroit Testing Laboratory. | 9th Sep 1929 | Box 135 \ 3 scan0095 | |
| Laboratory report on the analysis of an oil sample, detailing its water, sediment, and grit composition. | 9th Sep 1929 | Box 135 \ 3 scan0096 | |
| Laboratory report from The Detroit Testing Laboratory on an oil sample. | 9th Sep 1929 | Box 135 \ 3 scan0097 | |
| Laboratory report from The Detroit Testing Laboratory on an oil sample. | 9th Sep 1929 | Box 135 \ 3 scan0098 | |
| Laboratory report from The Detroit Testing Laboratory analyzing an oil sample. | 9th Sep 1929 | Box 135 \ 3 scan0099 | |
| Laboratory report on the percentage of water found in an oil sample after a series of brake application tests. | 6th Sep 1929 | Box 135 \ 3 scan0100 | |
| Laboratory report from The Detroit Testing Laboratory detailing the percentage of water in an oil sample. | 5th Sep 1929 | Box 135 \ 3 scan0101 | |
| Test report on a variable level oil intake indicator fitted to a B-4 Unit sump. | 30th Nov 1934 | Box 135 \ 3 scan0102 | |
| The behaviour of oil level indicators in aerated oil. | 30th Nov 1934 | Box 135 \ 3 scan0103 | |
| Fitting of a B.W.P. oil intake to an engine. | 23th Sep 1935 | Box 135 \ 3 scan0104 | |
| Order for a Variable Level Oil Intake from British Wire Products Ltd. | 23th Sep 1935 | Box 135 \ 3 scan0105 | |
| Letter from S. Smith & Sons regarding a No. 2 size Oil Filter being sent for test purposes. | 24th Apr 1936 | Box 135 \ 3 scan0106 | |
| Fitting instructions and oil pressure information for a Smith oil filter. | 24th Apr 1936 | Box 135 \ 3 scan0107 | |
| Technical bulletin regarding oil flow, observing results, and the life of an oil filter. | 24th Apr 1936 | Box 135 \ 3 scan0108 | |
| The use of colloidal graphite with the Smith's Filter during the engine running-in period. | 24th Apr 1936 | Box 135 \ 3 scan0109 | |
| Article detailing the extremely effective cleaning of a new oil filter by the Smith Accessory. | 1st Jan 1936 | Box 135 \ 3 scan0110 | |
| Reprint from 'The Automobile Engineer' describing the 'Smith' oil filter with test reports, issued by S. Smith & Sons. | 1st Jan 1936 | Box 135 \ 3 scan0111 | |
| Letter to S. Smith & Sons Ltd. regarding testing of an oil filter and requesting figures and a quotation. | 7th May 1936 | Box 135 \ 3 scan0112 | |
| Letter from S. Smith & Sons (Motor Accessories) Ltd regarding an oil filter and a proposed meeting. | 8th May 1936 | Box 135 \ 3 scan0113 | |
| Telegram from Steadman, Roycar to Grose, Speedofac regarding a meeting to discuss an oil filter. | 11th May 1936 | Box 135 \ 3 scan0114 | |
| Quotation from S. Smith & Sons for No. 2 size filters following recent tests. | 13th May 1936 | Box 135 \ 3 scan0115 | |
| Invoice from S. Smith & Sons for an oil filter and requesting an order be issued. | 20th May 1936 | Box 135 \ 3 scan0116 | |
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