| Description | Date | Identifier | |
| Instruction sheet recording an 'Autovac Test' with fuel consumption and distance data. | 19th Apr 1923 | Box 40 \ 4 Scan057 | |
| Road test instruction sheet to confirm test bed results for a vacuum tank petrol supply issue. | 2nd Jul 1923 | Box 40 \ 4 Scan058 | |
| Reduced performance of an autovac fuel system at an altitude of 15,000 feet. | 3rd May 1923 | Box 40 \ 4 Scan059 | |
| Continued technical explanation on the disadvantages of an autovac system for maintaining petrol supply to the engine. | 3rd May 1923 | Box 40 \ 4 Scan060 | |
| Analysis of the effects of high altitude on the Autovac petrol supply system and engine performance. | 4th May 1923 | Box 40 \ 4 Scan061 | |
| Numbered list describing factors affecting the Autovac fuel system and throttle operation. | 9th May 1923 | Box 40 \ 4 Scan062 | |
| Limitations of the vacuum feed system for the 40/50 HP chassis, particularly at high altitudes. | 9th May 1923 | Box 40 \ 4 Scan063 | |
| Vacuum versus pressure fuel feed systems, recommending the Autovac system but noting its limitations. | 9th May 1923 | Box 40 \ 4 Scan064 | |
| Table of test results for an Autovac system showing supply rates in pints per hour at full throttle under various RPM, fuel level, and gradient conditions. | 9th May 1923 | Box 40 \ 4 Scan065 | |
| Calculation sheet detailing the action of an Autovac fuel system at high altitudes. | 9th May 1923 | Box 40 \ 4 Scan066 | |
| Graph from Autovac tests showing the calculated distance possible to travel at full throttle in top gear. | 9th May 1923 | Box 40 \ 4 Scan067 | |
| Performance test results for an Autovac system, showing suction levels and travel distance against RPM. | 9th May 1923 | Box 40 \ 4 Scan068 | |
| Chart from Autovac tests showing the variation of petrol supply with height, fuel level, and vehicle gradient. | 1st May 1923 | Box 40 \ 4 Scan069 | |
| Parts from a 20 HP Autovac, specifically a Nut and Nipple that needs to be returned. | 1st May 1923 | Box 40 \ 4 Scan070 | |
| Requesting an order for a nut and nipple for the Goshawk II Autovac and Piping system. | 14th Jun 1923 | Box 40 \ 4 Scan071 | |
| From Mr. Royce requesting an experimental trial of a vacuum pump for the petrol system to potentially replace the Autovac system. | 30th Jun 1923 | Box 40 \ 4 Scan072 | |
| Mr. Royce's idea for a vacuum reservoir for the vacuum feed system on a 40/50 model. | 14th Jul 1923 | Box 40 \ 4 Scan073 | |
| The dispatch of one Autovac to the Paris Depot. | 10th Oct 1923 | Box 40 \ 4 Scan074 | |
| Despatch note for one Autovac to the French branch in Paris. | 6th Oct 1928 | Box 40 \ 4 Scan075 | |
| Malfunctioning Special Autovac System on a 40/50 chassis, requesting a valve replacement to fix restricted petrol flow. | 29th Jan 1924 | Box 40 \ 4 Scan076 | |
| Standardisation proposal for the Autovac Petrol Feed to improve its design. | 8th May 1924 | Box 40 \ 4 Scan077 | |
| Declining the testing of the 'Thecla' petrol elevator, stating a preference for their own in-house version. | 21th Aug 1924 | Box 40 \ 4 Scan078 | |
| Customer suggestion for a temporary filler cap on the Autovac fuel system for 20-HP & 40/50 HP models. | 10th Oct 1924 | Box 40 \ 4 Scan079 | |
| Suggesting the addition of a drain plug to the Autovac system for the 20-HP and 40/50 HP models. | 17th Oct 1924 | Box 40 \ 4 Scan080 | |
| Desirability of a drain plug for 'Autovac' tanks and requesting an inspection for accumulated sediment. | 28th Nov 1924 | Box 40 \ 4 Scan081 | |
| The discovery of dirt in Autovac tanks during vehicle testing and the suggested need for a washing method. | 27th Nov 1924 | Box 40 \ 4 Scan082 | |
| Issues with the starter motor and back axle on a 4-GOSHAWK-11 car. | 12th Aug 1924 | Box 40 \ 4 Scan083 | |
| Cover note regarding the Autovac Tank. | 10th Dec 1924 | Box 40 \ 4 Scan084 | |
| Proposed modifications to the Autovac tank for cleaning and emergency refilling. | 9th Dec 1924 | Box 40 \ 4 Scan085 | |
| Need for a filling plug on the autovac tank for the 20 HP model. | 11th Dec 1924 | Box 40 \ 4 Scan086 | |
| Draining, cleaning, and puncture risks of Autovac petrol tanks. | 22th May 1925 | Box 40 \ 4 Scan087 | |
| Intermittent misfiring on 'Silver Ghost' chassis related to the Autovac connection. | 22th May 1925 | Box 40 \ 4 Scan088 | |
| Admitting that the autovac connection on the induction pipe can affect slow running. | 27th May 1925 | Box 40 \ 4 Scan089 | |
| Letter to the Autovac Mfg. Co. Ltd. about a slow speed light running issue caused by the Autovac system. | 28th May 1925 | Box 40 \ 4 Scan090 | |
| Typed letter discussing an engine fault with petrol vapour in the Autovac system and requesting a solution. | 2nd Jun 1925 | Box 40 \ 4 Scan091 | |
| Letter from Autovac Manufacturing Co. Ltd acknowledging receipt of a letter regarding a complaint and experiments. | 2nd Jun 1925 | Box 40 \ 4 Scan092 | |
| Technical note on a modification to eliminate a mechanical tinkling noise from the Autovac system. | 13th Jun 1925 | Box 40 \ 4 Scan093 | |
| Modifications to a guide within a tank to ensure proper petrol flow. | 15th Jun 1925 | Box 40 \ 4 Scan094 | |
| Investigation into a mechanical noise from the Autovac, with a solution to fit a guide for the float spindle. | 15th Jun 1925 | Box 40 \ 4 Scan095 | |
| Follow-up letter to The Autovac Mfg. Co. Ltd. requesting a reply to a previous letter. | 15th Jun 1925 | Box 40 \ 4 Scan096 | |
| Order office memo regarding the dispatch of one N/P Autovac to the Autovac Mfg. Co in Stockport. | 15th Jun 1925 | Box 40 \ 4 Scan097 | |
| Letter from The Autovac Manufacturing Co. Ltd acknowledging receipt of a communication. | 16th Jun 1925 | Box 40 \ 4 Scan098 | |
| Request to forward recommendations regarding Chassis No. 41-TM for Col. C. Gerard. | 26th Jun 1925 | Box 40 \ 4 Scan099 | |
| Customer complaint regarding the Autovac Connection on the Induction Pipe. | 19th Jun 1925 | Box 40 \ 4 Scan100 | |
| Unresolved customer complaint for Chassis No. 41-TM. | 29th Jun 1925 | Box 40 \ 4 Scan101 | |
| Letter to The Autovac Mfg. Co. Ltd. about engine misfiring issues caused by the Autovac system. | 2nd Jul 1925 | Box 40 \ 4 Scan102 | |
| Letter from Autovac Manufacturing Co. Ltd. regarding experiments to improve their apparatus following feedback. | 3rd Jul 1925 | Box 40 \ 4 Scan103 | |
| Ongoing investigation into a complaint with an 'autovac' part. | 1st Jul 1925 | Box 40 \ 4 Scan104 | |
| Customer complaints of uneven slow running caused by the autovac system. | 1st Jul 1925 | Box 40 \ 4 Scan105 | |
| Autovac fuel mixture distribution issues and proposed solutions. | 1st Jul 1925 | Box 40 \ 4 Scan106 | |
| Letter from Autovac Mfg. Co. regarding experiments to overcome an issue with their apparatus enriching the fuel mixture. | 3rd Jul 1925 | Box 40 \ 4 Scan107 | |
| Covering memo from CJ to Hs regarding AUTOVAC, enclosing a copy of a memo from CWB. | 9th Jul 1925 | Box 40 \ 4 Scan108 | |
| Faults with the Autovac system and vacuum windscreen wiper, including customer complaints and potential remedies. | 9th Jul 1925 | Box 40 \ 4 Scan109 | |
| Letter from Autovac Manufacturing Co. Ltd about a new fitting to resolve engine speed variations at closed throttle. | 13th Jul 1925 | Box 40 \ 4 Scan110 | |
| Cross-sectional diagram of a non-return valve assembly. | 14th Jul 1925 | Box 40 \ 4 Scan111 | |
| Letter to The Autovac Mfg. Co. Ltd. arranging a meeting with their representative. | 14th Jul 1925 | Box 40 \ 4 Scan112 | |
| Letter from Autovac Manufacturing Co. Ltd. to arrange a representative's visit. | 16th Jul 1925 | Box 40 \ 4 Scan113 | |
| Letter to The Autovac Mfg. Co. Ltd. confirming a convenient day for their representative to visit. | 17th Jul 1925 | Box 40 \ 4 Scan114 | |
| Issues with the vacuum feed system on various models and considering alternatives. | 24th Jul 1925 | Box 40 \ 4 Scan115 | |
| Letter from Autovac Manufacturing regarding the supply of two Suction Elbow Connections. | 4th Aug 1925 | Box 40 \ 4 Scan116 | |
| Inquiring about the progress of experiments on a vacuum feed system and any recent communication from the Autovac Manufacturing Co. | 6th Aug 1925 | Box 40 \ 4 Scan117 | |
| Order be placed with Autovac Mfg. Co. Ltd. for special suction elbow connections. | 1st Aug 1925 | Box 40 \ 4 Scan118 | |
| Instructing to carry on experiments on Autovac fittings and silencer tests. | 1st Aug 1925 | Box 40 \ 4 Scan119 | |
| Faults in the pressure-fed petrol system and proposing solutions to overcome issues with the Autovac system. | 13th Aug 1925 | Box 40 \ 4 Scan120 | |
| Attached testers report on the New Phantom Vacuum Feed Tank. | 14th Aug 1925 | Box 40 \ 4 Scan121 | |
| Investigations into the effect of the vacuum feed on slow engine running. | 14th Aug 1925 | Box 40 \ 4 Scan122 | |
| Page 2, detailing tests on the Autovac fuel system by introducing pure air or exhaust gas to mitigate 'lumpy' running. | 12th Jun 1925 | Box 40 \ 4 Scan123 | |
| Modified suction elbow for an Autovac system. | 12th Aug 1925 | Box 40 \ 4 Scan124 | |
| Spring-loaded piston's effect on carburetted air and Autovac efficiency. | 13th Aug 1925 | Box 40 \ 4 Scan125 | |
| Graph comparing the performance of a modified suction elbow against a standard one based on the time taken to fill an Autovac float chamber. | 12th Aug 1925 | Box 40 \ 4 Scan126 | |
| Blank document page with a print room stamp. | 13th Aug 1925 | Box 40 \ 4 Scan127 | |
| Graph showing the effect of a modified suction elbow on depression in an Autovac, comparing it to the standard part. | 12th Sep 1925 | Box 40 \ 4 Scan128 | |
| Page marked with a red ink stamp from the print room. | 13th Aug 1925 | Box 40 \ 4 Scan129 | |
| Issues with and proposing modifications for the New Phantom vacuum feed tank. | 17th Aug 1925 | Box 40 \ 4 Scan130 | |
| Technical memorandum responding to complaints from Lord Montagu regarding steering rigidity and the Autovac system. | 8th Aug 1925 | Box 40 \ 4 Scan131 | |
| Note on the correct operational position of the ignition lever. | 28th Sep 1925 | Box 40 \ 4 Scan132 | |
| Operational issues and proposed modifications for autovac tanks, including a suggestion from Mr. Royce. | 28th Sep 1925 | Box 40 \ 4 Scan133 | |
| Autopulse system as an alternative scheme to the Autovac. | 30th Sep 1925 | Box 40 \ 4 Scan134 | |
| Testing a non-return valve for the 'Phantom' vacuum feed system to eliminate engine fading. | 12th Oct 1925 | Box 40 \ 4 Scan135 | |
| Letter to The Autovac Co. regarding tests on modified suction elbows and their potential standard fitment. | 29th Oct 1925 | Box 40 \ 4 Scan136 | |
| Report comparing the operation of Stewart and Autovac trip valves and detailing improvements made to the Autovac system. | 30th Oct 1925 | Box 40 \ 4 Scan137 | |
| Diagram and notes regarding a flap valve on the fuel inlet of an Autovac tank. | 3rd Nov 1925 | Box 40 \ 4 Scan138 | |
| Letter from Autovac Manufacturing Co. Ltd. regarding the supply of special Suction Elbows as a standard fitment. | 3rd Nov 1925 | Box 40 \ 4 Scan139 | |
| Ordering modified suction elbows for the 'New Phantom' Autovac and the requirement for a Standardisation Sheet. | 9th Nov 1925 | Box 40 \ 4 Scan140 | |
| New elbows for the Autovac system designed to reduce engine misfiring at light load. | 13th Nov 1925 | Box 40 \ 4 Scan141 | |
| The cause of 'dumping' in the Autovac system and attempted solutions. | 13th Nov 1925 | Box 40 \ 4 Scan142 | |
| Explaining why suction in the Autovac is higher than in the induction pipe, due to a non-return valve. | 1st Nov 1925 | Box 40 \ 4 Scan143 | |
| The performance of an experimental elbow for the Autovac system, noting a 50% fault reduction. | 14th Nov 1925 | Box 40 \ 4 Scan144 | |
| Experience with an experimental Elbow for the Autovac system. | 16th Nov 1925 | Box 40 \ 4 Scan145 | |
| 50% improvement derived from an Autovac modification using an experimental elbow. | 18th Nov 1925 | Box 40 \ 4 Scan146 | |
| Letter from The Autovac Manufacturing Co. Ltd. about variations in their Galometer and Measuring Autovac apparatus. | 19th Nov 1925 | Box 40 \ 4 Scan147 | |
| Cablegram reporting a solution for an Autovac misfiring issue. | 30th Nov 1925 | Box 40 \ 4 Scan148 | |
| Letter to the Autovac Mfg. Co. Ltd. querying the function of a non-return valve in a new measuring Autovac system. | 30th Nov 1925 | Box 40 \ 4 Scan149 | |
| Letter discussing the operation of the Autovac fuel system, float, and suction valve mechanisms. | 30th Nov 1925 | Box 40 \ 4 Scan150 | |
| Patent infringement lawsuit between the Autovac Company and the Grav-Vac Syndicate. | 30th Nov 1925 | Box 40 \ 4 Scan151 | |
| Letter from Autovac Manufacturing Co. Ltd. explaining the function of their Galometer and Measuring Autovac. | 1st Dec 1925 | Box 40 \ 4 Scan152 | |
| The accuracy and installation of an Autovac Galometer. | 1st Dec 1925 | Box 40 \ 4 Scan153 | |
| Response from the Autovac Company concerning potential errors in their Galometer and plans for testing. | 2nd Dec 1925 | Box 40 \ 4 Scan154 | |
| Letter from The Autovac Co. regarding the functionality of their Galometer and Measuring Autovac system. | 1st Dec 1925 | Box 40 \ 4 Scan155 | |
| Testing an alternative suction Autovac system on a 5-EX Silver Ghost car. | 3rd Dec 1925 | Box 40 \ 4 Scan156 | |
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