| Description | Date | Identifier | |
| Recommendation to modify petrol tank filters by drilling air holes for cars destined for America. | 6th Jul 1921 | Box 135 \ 2 scan0044 | |
| Extract about modifying petrol tank filters on cars for America to increase the filling rate. | 6th Jul 1921 | Box 135 \ 2 scan0045 | |
| Letter regarding proposed design improvements for the 40/50 HP rear tank. | 11th Aug 1921 | Box 135 \ 2 scan0046 | |
| Issue of a filter freezing in the back tank. | 9th Sep 1921 | Box 135 \ 2 scan0047 | |
| Letter from Rolls-Royce of America about petrol filter blockages caused by water in American gasoline freezing. | 28th Sep 1921 | Box 135 \ 2 scan0048 | |
| Recommendation concerning Monel metal petrol gauze for the Goshawk petrol filter. | 30th Jan 1923 | Box 135 \ 2 scan0049 | |
| Choked mono-metal petrol filter in a 40/50 Works Trials Car and requesting an investigation. | 29th Jan 1924 | Box 135 \ 2 scan0050 | |
| Fault with a 40/50 petrol filter, attributing the cause to the use of zinc chloride or acid soldering flux. | 1st Jan 1924 | Box 135 \ 2 scan0051 | |
| Multiple instances of choked petrol filters on the 40/50 model and proposing further action. | 8th Apr 1924 | Box 135 \ 2 scan0052 | |
| Standardisation of gauze for petrol filters on 40/50 & 20 HP models. | 15th Apr 1924 | Box 135 \ 2 scan0053 | |
| Design and necessity of petrol filters for carburettors on aero and other engines. | 10th Aug 1924 | Box 135 \ 2 scan0054 | |
| Mesh size and material for filters at the base of the carburetter. | 3rd Nov 1924 | Box 135 \ 2 scan0055 | |
| Alterations to the petrol filter gauze on the carburetter float chamber for a 40/50HP Chassis. | 3rd Nov 1924 | Box 135 \ 2 scan0056 | |
| Reintroduction and design of more adequate petrol filters for the 40/50HP and 20HP models. | 11th Dec 1924 | Box 135 \ 2 scan0057 | |
| Importance and placement of petrol filters, arguing against omitting them at the petrol tank entrance. | 13th Dec 1924 | Box 135 \ 2 scan0058 | |
| Proposal to address sand and metal particles in the petrol tank system by experimenting with enameling the component castings. | 15th Dec 1924 | Box 135 \ 2 scan0059 | |
| Issues with petrol filters, the source of debris in the fuel system, and recommendations for filter design. | 15th Dec 1924 | Box 135 \ 2 scan0060 | |
| Issues with petrol filters, including trustworthiness, foreign matter, and specific problems on the 20 HP model. | 17th Dec 1924 | Box 135 \ 2 scan0061 | |
| Page two of a communication discussing petrol supply troubles and seeking feedback. | 19th Dec 1924 | Box 135 \ 2 scan0062 | |
| Petrol filter maintenance and potential improvements. | 19th Dec 1924 | Box 135 \ 2 scan0063 | |
| Arranging a conference about petrol filters in Derby. | 1st Jan 1925 | Box 135 \ 2 scan0064 | |
| To reschedule a conference on Lubricators and Petrol Filters from Thursday to Wednesday. | 1st Jan 1925 | Box 135 \ 2 scan0065 | |
| Petrol filters and rear tank specifications, considering global fuel quality and filling practices. | 20th Aug 1925 | Box 135 \ 2 scan0066 | |
| Specifications and issues with fuel filter gauzes, including mesh size and material. | 1st Aug 1925 | Box 135 \ 2 scan0067 | |
| The carburetter's low speed needle taper, altered filter mesh, and a request for a replacement filter. | 1st Aug 1925 | Box 135 \ 2 scan0068 | |
| Appropriate coarseness of gauze for filters in carburettors to prevent choked petrol jets. | 24th Aug 1925 | Box 135 \ 2 scan0069 | |
| Page describing the flow path through annular spaces within a chamber leading to a jet. | 24th Aug 1925 | Box 135 \ 2 scan0070 | |
| Petrol filter issues for 20 HP and 40/50 HP models, focusing on blockages caused by fluff and hairs. | 1st Aug 1925 | Box 135 \ 2 scan0071 | |
| Petrol filter configurations and issues across various car models. | 1st Aug 1925 | Box 135 \ 2 scan0072 | |
| Use of 160 mesh monel metal gauze in petrol filters for carburetters. | 1st Sep 1925 | Box 135 \ 2 scan0073 | |
| Design, issues, and required improvements for petrol filters on Phantom and Goshawk models. | 29th Sep 1925 | Box 135 \ 2 scan0074 | |
| Improving outgoing filters compared to the previous Silver Ghost model. | 17th Nov 1925 | Box 135 \ 2 scan0075 | |
| Confirming the use of the finest mesh gauze (160) in filters and asking about retrospective action. | 17th Nov 1925 | Box 135 \ 2 scan0076 | |
| Design improvements and issues for petrol fillers and petrol gauges. | 15th Feb 1926 | Box 135 \ 2 scan0077 | |
| Improvements and standardization of the rear petrol tank, carrier, and guard. | 27th Feb 1926 | Box 135 \ 2 scan0078 | |
| Issues with petrol filters on 20 HP cars and proposed solutions. | 3rd Jun 1926 | Box 135 \ 2 scan0079 | |
| Making arrangements to lock the nut holding the oil filter. | 1st Oct 1926 | Box 135 \ 2 scan0080 | |
| The petrol tank filler for the 20 HP model, noting differences from the Phantom's filler and an alteration to suspension links. | 1st Mar 1926 | Box 135 \ 2 scan0081 | |
| Revisions to a petrol tank side filler, vent pipe, and fittings. | 1st Mar 1926 | Box 135 \ 2 scan0082 | |
| Alteration for an improved air vent and larger filler in the petrol tank to prevent overflowing. | 24th Sep 1926 | Box 135 \ 2 scan0083 | |
| Modification to the petrol tank filter fitting to allow for easier withdrawal. | 18th Jan 1927 | Box 135 \ 2 scan0084 | |
| Requesting a quantitative report on 6 more samples of filtrate. | 2nd Feb 1927 | Box 135 \ 2 scan0085 | |
| Tests on petrol filters to address issues with choked jets caused by fluff contamination. | 25th Feb 1927 | Box 135 \ 2 scan0086 | |
| Investigation into foreign matter causing choked fuel jets and a comparison of filter designs. | 25th Feb 1927 | Box 135 \ 2 scan0087 | |
| The performance and road testing of a Zenith petrol filter, including its capacity and self-cleaning ability. | 25th Feb 1927 | Box 135 \ 2 scan0088 | |
| Evaluation of Auto Klean and Chamois leather strainers and filters, with a summary of their potential. | 25th Feb 1927 | Box 135 \ 2 scan0089 | |
| Modification to a Zenith filter to prevent air from being trapped. | 5th Apr 1923 | Box 135 \ 2 scan0090 | |
| Two photomicrographs comparing fluff from a choked jet with a standard carburetter petrol filter gauze. | 5th Apr 1923 | Box 135 \ 2 scan0091 | |
| Photomicrograph comparison of foreign matter passed through a Standard Gauze versus a Zenith filter. | 5th Apr 1923 | Box 135 \ 2 scan0092 | |
| Blueprint detailing modifications to a Zenith petrol filter. | 1st Mar 1927 | Box 135 \ 2 scan0093 | |
| Micro-examination report on carburetter filter gauges and foreign matter that passed through them. | 28th Feb 1927 | Box 135 \ 2 scan0094 | |
| Returning a piece of fluff extracted from a carburetter low speed jet. | 1st Mar 1927 | Box 135 \ 2 scan0095 | |
| Filters and low-speed running issues for the Phantom and 20 HP models. | 12th Mar 1927 | Box 135 \ 2 scan0096 | |
| Cancellation of existing petrol filters upon the introduction of a new type into the production programme. | 20th Jul 1927 | Box 135 \ 2 scan0097 | |
| Customer complaints of paint damage caused by leaking petrol tank filters. | 1st May 1928 | Box 135 \ 2 scan0098 | |
| Issues with petrol tank filters, specifically leakage due to jointing material and dismantling procedures. | 7th May 1928 | Box 135 \ 2 scan0099 | |
| Required coachwork alterations for removing petrol tank filters on a 20 HP chassis. | 15th May 1928 | Box 135 \ 2 scan0100 | |
| Issue with petrol vaporisation in the feed pipe on a Phantom chassis and proposing a solution. | 23th Oct 1923 | Box 135 \ 2 scan0101 | |
| Approval for a trunk fixing, petrol tank support, and a large petrol filter for SS Chassis X.7460 and X.3701. | 18th Feb 1929 | Box 135 \ 2 scan0102 | |
| Design of a single petrol tank filter and its potential use on the 20 HP model. | 2nd Feb 1929 | Box 135 \ 2 scan0103 | |
| Testing a petrol filter for leaks at the soldered joints and its effect on autovac delivery. | 11th Mar 1930 | Box 135 \ 2 scan0104 | |
| Continuation of a test report comparing fuel delivery through a special petrol filter versus a standard filter at various RPMs. | 24th May 1930 | Box 135 \ 2 scan0105 | |
| Revised position of the petrol filter and potential issues with air locks. | 24th May 1930 | Box 135 \ 2 scan0106 | |
| Requesting the manufacture of an aluminium petrol filter bowl based on a glass sample. | 27th Feb 1934 | Box 135 \ 2 scan0107 | |
| Request to design and create a new interchangeable 'Enot plate type' Spectre Petrol Filter. | 12th Jun 1935 | Box 135 \ 2 scan0108 | |
| Relocation of the Spectre Petrol Filter from the dashboard to the chassis to prevent vapour locks. | 16th Aug 1935 | Box 135 \ 2 scan0109 | |
| Requesting a Spectre Petrol Filter Bowl and initiating work on Spectre I and II vehicles. | 17th Aug 1935 | Box 135 \ 2 scan0110 | |
| Requesting the fitting of Spectre Petrol Filter, Scheme LeC. 4594, to Spectres 4, 5 & 6. | 3rd Sep 1935 | Box 135 \ 2 scan0111 | |
| Petrol filter siphoning issue and the proposed solution of fitting a tap. | 12th Sep 1935 | Box 135 \ 2 scan0112 | |
| Instructions for fitting a petrol filter to a Spectre 2-S-I for a 10,000 mile test run. | 19th Sep 1935 | Box 135 \ 2 scan0113 | |
| New petrol filter design for the Phantom III and Bentley models, cancelling a previous design. | 7th Oct 1935 | Box 135 \ 2 scan0114 | |
| Request to make one Phantom III petrol filter for testing purposes. | 2nd Dec 1935 | Box 135 \ 2 scan0115 | |
| The fitting of the Big Bore Bentley petrol filter. | 1st Jan 1936 | Box 135 \ 2 scan0116 | |
| Quotation from Benton & Stone Ltd. for petrol filters and stamping dies. | 2nd Jan 1936 | Box 135 \ 2 scan0117 | |
| Letter from supplier Benton & Stone regarding a quotation and manufacturing modifications for a petrol filter. | 2nd Jan 1936 | Box 135 \ 2 scan0118 | |
| Letter from Benton & Stone Ltd. suggesting a modification to a domed cover to prevent a cork washer from being lost. | 2nd Jan 1936 | Box 135 \ 2 scan0119 | |
| Request for a cost estimate to manufacture petrol filters and part number LeC.4721. | 4th Jan 1936 | Box 135 \ 2 scan0120 | |
| Cost estimation for a petrol filter based on Scheme LEC.4721. | 4th Jan 1936 | Box 135 \ 2 scan0121 | |
| The use of a new filter, LeC.4721, on all cars. | 7th Jan 1936 | Box 135 \ 2 scan0122 | |
| Estimated cost of a new petrol filter compared to the existing Enots filter on Bentley and 20/25HP chassis. | 4th Jan 1936 | Box 135 \ 2 scan0123 | |
| Quotation letter from Benton & Stone Ltd. for petrol filters and stamping dies. | 2nd Jan 1936 | Box 135 \ 2 scan0124 | |
| Letter providing a quotation and suggested manufacturing modifications for a petrol filter. | 2nd Jan 1936 | Box 135 \ 2 scan0125 | |
| Letter from Benton & Stone Ltd. suggesting a design modification to a domed cover and cork washer. | 2nd Jan 1936 | Box 135 \ 2 scan0126 | |
| Request to order 6 Tecalemit filters for use on the Experimental Unit Test Beds. | 11th Jan 1936 | Box 135 \ 2 scan0127 | |
| Confirming the new position of the petrol filter on the Phantom III chassis. | 14th Jan 1936 | Box 135 \ 2 scan0128 | |
| Standardisation of the Bentley petrol filter on the second cross member, and the need for a protective shield. | 15th Jan 1936 | Box 135 \ 2 scan0129 | |
| Request for an estimate of the cost to manufacture various petrol unions and filter plugs in Stainless Steel and B/ZS. | 16th Jan 1936 | Box 135 \ 2 scan0130 | |
| Requirement to lengthen the stud on the Petrol Filter LeC.4721. | 20th Jan 1936 | Box 135 \ 2 scan0131 | |
| Providing a comparative cost estimate for petrol unions and plugs in B/ZS and S/S materials. | 21th Jan 1936 | Box 135 \ 2 scan0132 | |
| To pass an official order for 6 filters received from the Tecalemit Co. | 24th Jan 1936 | Box 135 \ 2 scan0133 | |
| Letter to Rotherham & Sons Ltd. requesting a quotation for the supply of parts based on enclosed drawings. | 24th Jan 1936 | Box 135 \ 2 scan0134 | |
| Letter to Messrs Brown Bros. requesting a quotation for the supply of various parts with enclosed drawings. | 24th Jan 1936 | Box 135 \ 2 scan0135 | |
| Letter from Brown Brothers Ltd. acknowledging an enquiry and requesting quantities needed to provide a quotation. | 27th Jan 1936 | Box 135 \ 2 scan0136 | |
| Letter to Brown Bros. Ltd. requesting a price quotation for various quantities of unions and plugs. | 28th Jan 1936 | Box 135 \ 2 scan0137 | |
| Urgent internal request to order 12 Tecalemit filters for experimental chassis unit beds. | 29th Jan 1936 | Box 135 \ 2 scan0138 | |
| Letter from Rotherham & Sons Ltd. requesting material samples and quantities before providing a quotation for parts. | 30th Jan 1936 | Box 135 \ 2 scan0139 | |
| Letter to Messrs. Rotherham & Sons Ltd. returning drawings and requesting a quotation for various quantities of stainless steel parts. | 5th Feb 1936 | Box 135 \ 2 scan0140 | |
| Letter from Rotherham & Sons Ltd declining to quote for work due to a lack of capable machinery to handle specification 229B. | 6th Feb 1936 | Box 135 \ 2 scan0141 | |
| Request for a report on the rearranged Phantom III petrol filter. | 10th Feb 1936 | Box 135 \ 2 scan0142 | |
| Request for a performance report on the rearranged Phantom III petrol filter. | 10th Feb 1936 | Box 135 \ 2 scan0143 | |
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