| Description | Date | Identifier | |
| The effectiveness of air cleaners for carburettor intakes, citing findings from Leyland Motors Ltd. | 1st Aug 1928 | Box 135 \ 4 scan0108 | |
| Inquiry to The S.U. Company regarding a proprietary air cleaner used on a horizontal carburetter. | 13th Jul 1931 | Box 135 \ 4 scan0109 | |
| Letter from The S.U. Company regarding a recommended air cleaner for a carburetter. | 14th Jul 1931 | Box 135 \ 4 scan0110 | |
| Inquiry to F. Smith & Sons for particulars of an air cleaner for an S.U. carburetter. | 16th Jul 1931 | Box 135 \ 4 scan0111 | |
| Letter from Frank Smith & Co. about supplying an AFN.type air filter for trial and asking to confirm intake dimensions. | 18th Jul 1931 | Box 135 \ 4 scan0112 | |
| Advertising brochure for the 'Smith' air filter with silencer and warning whistle. | 18th Jul 1931 | Box 135 \ 4 scan0113 | |
| The 'Smith' Air Filter with Silencer & Warning Whistle, its function, and maintenance. | 20th Jul 1931 | Box 135 \ 4 scan0114 | |
| Letter to F. Smith & Co. requesting a sample air cleaner for trial, specifying the carburetter dimensions. | 20th Jul 1931 | Box 135 \ 4 scan0115 | |
| Letter from Frank Smith & Co. following up on an AF3N 1.7 air filter sent to the Experimental Department. | 9th Oct 1931 | Box 135 \ 4 scan0116 | |
| Letter to Frank Smith & Co. regarding air filter testing and a request for a similar type with a sketch attached. | 12th Oct 1931 | Box 135 \ 4 scan0117 | |
| Blueprint for an Air Silencer for a S.U. 1 7/8 Carburettor. | 10th Oct 1931 | Box 135 \ 4 scan0118 | |
| Letter from Frank Smith & Co. regarding the development and supply of an air filter for an S.U. carburetter. | 13th Oct 1931 | Box 135 \ 4 scan0119 | |
| Delivery note from Frank Smith & Co. for air filters sent for trial. | 13th Oct 1931 | Box 135 \ 4 scan0120 | |
| Letter from Frank Smith & Co. regarding the supply, pricing, and specifications of AF3N air filters for use with S.U. carburettors. | 21th Dec 1931 | Box 135 \ 4 scan0121 | |
| Letter to Frank Smith & Co requesting a quotation for air filters and wire wool filtering medium pads. | 28th Dec 1931 | Box 135 \ 4 scan0122 | |
| The preparation of wire and worsted material for air filters. | 23th Nov 1932 | Box 135 \ 4 scan0123 | |
| Potential choking of Voke's air filters on Bentleys and a proposal to test oil carb cleaners for the Phantom III model in Africa. | 25th Jan 1937 | Box 135 \ 4 scan0124 | |
| Request to place an official order for four Burgess Air Filters for experimental testing. | 17th Feb 1937 | Box 135 \ 4 scan0125 | |
| Two revised designs for the 'A.C.' bye-pass filter mounting to address failures experienced during testing. | 9th Apr 1938 | Box 135 \ 4 scan0126 | |
| Standardisation and pricing of Vokes and Burges filter elements. | 12th May 1938 | Box 135 \ 4 scan0127 | |
| Letter from Air-Maze (Great Britain) Ltd. promoting their air filters and flame arresters. | 25th Aug 1938 | Box 135 \ 4 scan0128 | |
| Letter to Air Maze Ltd. arranging a meeting with Mr. Walton regarding Air-Maze Filters. | 5th Sep 1938 | Box 135 \ 4 scan0129 | |
| Letter from Air-Maze (Great Britain) Ltd. offering to demonstrate an Air-Maze filter. | 5th Dec 1938 | Box 135 \ 4 scan0130 | |
| Promotional leaflet for Air-Maze air filters, outlining their benefits, types, and applications. | 5th Dec 1938 | Box 135 \ 4 scan0131 | |
| Advertising brochure for Air-Maze air filters, detailing the Oil Bath and Unimaze types. | 7th Dec 1938 | Box 135 \ 4 scan0132 | |
| Letter from the Experimental Department to Air Maze Ltd. arranging a meeting. | 7th Dec 1938 | Box 135 \ 4 scan0133 | |
| Letter from Air-Maze (Great Britain) Ltd. arranging a meeting for the following Wednesday. | 12th Dec 1938 | Box 135 \ 4 scan0134 | |
| Letter from Air-Maze confirming the production of a sample oil bath air filter and future quotations. | 20th Dec 1938 | Box 135 \ 4 scan0135 | |
| Letter from Air-Maze (Great Britain) Limited discussing the design of an oil bath filter for a 25/30 HP unit. | 20th Dec 1938 | Box 135 \ 4 scan0136 | |
| Continuation sheet of a letter from W.F. McGloon, Sales Manager of Air-Maze (Great Britain) Limited. | 13th Jan 1939 | Box 135 \ 4 scan0137 | |
| Letter to Air-Maze Ltd. from the Experimental Department requesting an air filter for testing purposes. | 13th Jan 1939 | Box 135 \ 4 scan0138 | |
| Letter from Air-Maze (Great Britain) Limited confirming the production of an Air-Maze Oil bath filter. | 18th Jan 1939 | Box 135 \ 4 scan0139 | |
| Letter from Air-Maze (Great Britain) Limited regarding a delay in manufacturing a non-standard oil bath filter sample. | 6th Feb 1939 | Box 135 \ 4 scan0140 | |
| Letter from Air-Maze to the Experimental Department confirming completion and proposing delivery of an oil bath filter. | 18th Apr 1939 | Box 135 \ 4 scan0141 | |
| Letter from Air-Maze (Great Britain) Limited regarding air filters and an attached blueprint for an aircraft filter panel. | 21th Apr 1939 | Box 135 \ 4 scan0142 | |
| Letter from Air-Maze (Great Britain) Limited concerning a sample oil bath filter, including instructions and pricing. | 29th Apr 1939 | Box 135 \ 4 scan0143 | |
| Letter from Air-Maze following up on the performance of an oil bath air filter being tested on an experimental chassis. | 19th Jun 1939 | Box 135 \ 4 scan0144 | |
| Letter to Air-Maze Ltd. explaining a delay in testing their oil bath filter. | 24th Jun 1939 | Box 135 \ 4 scan0145 | |
| Letter from Air-Maze (Great Britain) Limited acknowledging correspondence. | 27th Jun 1939 | Box 135 \ 4 scan0146 | |
| Letter from Air-Maze (Great Britain) Limited proposing a meeting in Derby. | 24th Nov 1939 | Box 135 \ 4 scan0147 | |
| Letter from Air-Maze (Great Britain) Limited regarding a sample oil bath air filter and a handwritten response. | 5th Dec 1939 | Box 135 \ 4 scan0148 | |
| Letter from Air-Maze (Great Britain) Limited regarding tests on an oil-washing type filter. | 20th Jun 1940 | Box 135 \ 4 scan0149 | |
| Letter to Air-Maze, Limited, regarding a sample air filter and the halt of motor car development due to the war. | 23th Jun 1940 | Box 135 \ 4 scan0150 | |
| Letter from Air-Maze (Great Britain) Limited concerning an Air-Maze air filter for a 25-HP engine unit. | 3rd Jul 1940 | Box 135 \ 4 scan0151 | |
| Letter to Air-Maze Ltd. explaining that their cleaner cannot be installed due to altered engine mountings. | 7th Jul 1940 | Box 135 \ 4 scan0152 | |
| Request to borrow an AutoKlean filter from the Experimental Test Beds. | 22th Jul 1940 | Box 135 \ 4 scan0153 | |
| Arranging a visit from a representative of Air-Maze Ltd. to Derby. | 26th Jun 1941 | Box 135 \ 4 scan0154 | |
| Modifications to front timing gears to resolve trouble and expense. | 11th Apr 1911 | Box 136 \ 1 scan0001 | |
| To Mr. Swetnam requesting instructions be sent to the shop to produce a set of heavier bronze engine gears. | 22th Sep 1911 | Box 136 \ 1 scan0002 | |
| Meeting minutes discussing the delivery of engine gears and a design for a wheel withdrawal device. | 23th Oct 1911 | Box 136 \ 1 scan0003 | |
| The design of engine gears, specifically requesting a device for withdrawing the wheel from the camshaft. | 23th Oct 1911 | Box 136 \ 1 scan0004 | |
| Meeting minutes regarding the production status of brass and iron timing gears for the 1900 Series. | 13th Nov 1911 | Box 136 \ 1 scan0005 | |
| Test report on Cast Iron and Phosphor Bronze gears. | 11th Oct 1911 | Box 136 \ 1 scan0006 | |
| Meeting minutes discussing the testing of bronze versus cast iron timing gears for the 1900 series. | 30th Nov 1911 | Box 136 \ 1 scan0007 | |
| Meeting minute extract regarding the testing of bronze and cast iron timing gears for the 1900 series. | 7th Dec 1911 | Box 136 \ 1 scan0008 | |
| Meeting note discussing a report on noisy engine gears and the lengthy experiments required to find a solution. | 8th Dec 1911 | Box 136 \ 1 scan0009 | |
| Meeting notes regarding the testing of cast iron timing gears for the 1900 series and the delivery of more material. | 28th Dec 1911 | Box 136 \ 1 scan0010 | |
| Record card detailing the supply and status of C.S. timing gears to the Test Department. | 29th Dec 1911 | Box 136 \ 1 scan0011 | |
| Meeting minutes discussing the issue of noisy engine gears and ongoing tests with alternative materials. | 4th Jan 1912 | Box 136 \ 1 scan0012 | |
| Gear stripping failure on car No. 763 and the decision to design a spring drive to isolate crankshaft vibration. | 24th Apr 1912 | Box 136 \ 1 scan0013 | |
| Potential change to the timing gear case and base chamber and its associated cost. | 26th Aug 1912 | Box 136 \ 1 scan0014 | |
| Small tooth sewing wheels in chrome nickel steel. | 26th Aug 1912 | Box 136 \ 1 scan0015 | |
| Noisy paper timing gears on Chassis 2090 E. and the hope for new helical gears. | 20th Dec 1912 | Box 136 \ 1 scan0016 | |
| The timing gears of experimental chassis number 1649. | 23th Sep 1913 | Box 136 \ 1 scan0017 | |
| Inspection report on timing wheel sizes and the condition of related components. | 30th Apr 1913 | Box 136 \ 1 scan0018 | |
| Instructions regarding the Slipper Drive, Crank pinion springs, and Fibre Rings. | 30th Apr 1913 | Box 136 \ 1 scan0019 | |
| Standardisation proposal to cancel the covers for thrust bearings on engine gears. | 3rd Oct 1923 | Box 136 \ 1 scan0020 | |
| Proposal to increase the depth of engine timing gears to eliminate the need for topping by grinding. | 1st Nov 1924 | Box 136 \ 1 scan0021 | |
| The design and lubrication of an adjustable carrier wheel. | 31th Mar 1928 | Box 136 \ 1 scan0022 | |
| That the teeth for the Super Sports Engine timing gears be cut after assembly. | 28th Aug 1928 | Box 136 \ 1 scan0023 | |
| Alterations to engine timing with diagrams for two new proposed camshafts. | 30th Aug 1928 | Box 136 \ 1 scan0024 | |
| The manufacturing process and interchangeability of engine timing gears for a super sports car. | 6th Sep 1928 | Box 136 \ 1 scan0025 | |
| Modification to fix an oil leak from the timing gears on 'SS' engines by reducing the nozzle diameter. | 12th Nov 1928 | Box 136 \ 1 scan0026 | |
| Sketch showing a restriction in the timing gears' oil pipe for a Super Sports model. | 12th Nov 1928 | Box 136 \ 1 scan0027 | |
| The decision not to modify an oil pipe for the 'S.S.' Timing Gear lubrication. | 22th Nov 1928 | Box 136 \ 1 scan0028 | |
| Provision for end adjustment on timing gears to enable lining them up. | 29th Jan 1929 | Box 136 \ 1 scan0029 | |
| Suggestion for cheaper Peregrine timing gears using a 45° spiral angle. | 30th May 1932 | Box 136 \ 1 scan0030 | |
| Blueprint detailing the specifications and tooth profile for the Peregrine engine gears. | 28th Jun 1932 | Box 136 \ 1 scan0031 | |
| Two schemes for a Bensports timing gear layout, including details for overhead camshafts and a gear-driven blower. | 28th Jun 1932 | Box 136 \ 1 scan0032 | |
| Uncorrected blueprint for a modified stroke, crankpin diameter, and a new scheme for timing gear drives. | 28th Jun 1932 | Box 136 \ 1 scan0033 | |
| Standardisation of chassis parts report for a brake on a dynamo pinion for a 20/25 B.HP engine. | 11th Jul 1932 | Box 136 \ 1 scan0034 | |
| Implementation costs and schedule for fitting a new chassis part. | 16th May 1933 | Box 136 \ 1 scan0035 | |
| The timing for experimental car camshafts. | 16th May 1933 | Box 136 \ 1 scan0036 | |
| Causes and potential solutions for engine gear rattles. | 30th May 1933 | Box 136 \ 1 scan0037 | |
| Evaluating various design options for engine drive mechanisms, including brakes and dampers. | 30th May 1933 | Box 136 \ 1 scan0038 | |
| Letter to Messrs Lendrum & Hartman Ltd. requesting to purchase a Buick timing gear and asking for details on its material composition. | 2nd Jun 1933 | Box 136 \ 1 scan0039 | |
| Inquiry regarding the material 'Texolit' used in Buick car timing gears and its availability in the country. | 2nd Jun 1933 | Box 136 \ 1 scan0040 | |
| Urgent internal memo requesting enquiries into obtaining Texolit blanks for timing gears. | 2nd Jun 1933 | Box 136 \ 1 scan0041 | |
| Design and materials of engine timing gears from Buick and Cadillac. | 3rd Jun 1933 | Box 136 \ 1 scan0042 | |
| Illustration of a Timing Gear Case. | 6th Jun 1933 | Box 136 \ 1 scan0043 | |
| Letter from Buick concessionaires regarding a Buick Timing Gear and its Textalite component. | 6th Jun 1933 | Box 136 \ 1 scan0044 | |
| Letter of thanks to Messrs Lendrum & Hartman Ltd. for their letter and the timing gear. | 7th Jun 1933 | Box 136 \ 1 scan0045 | |
| The preparation of a modified set of Bensport timing gears for trial. | 7th Jun 1933 | Box 136 \ 1 scan0046 | |
| Invoice from Lendrum & Hartman for a Buick Camshaft Gear. | 13th Jun 1933 | Box 136 \ 1 scan0047 | |
| Order to be passed for a Buick camshaft gear. | 14th Jun 1933 | Box 136 \ 1 scan0048 | |
| Fabroil Gear samples and their material properties for testing. | 17th Jun 1933 | Box 136 \ 1 scan0049 | |
| Gear design principles and providing Fabroil material for an experiment. | 17th Jun 1933 | Box 136 \ 1 scan0050 | |
| Specifications for Bentley timing gears. | 22th Jun 1933 | Box 136 \ 1 scan0051 | |
| Modifications to a cam pinion and crankdamper to investigate engine gear rattles. | 23th Jun 1933 | Box 136 \ 1 scan0052 | |
| Drawing of a slipping inertia for a spring-driven cam pinion. | 26th Jun 1933 | Box 136 \ 1 scan0053 | |
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