| Description | Date | Identifier | |
| The limitations of the Autovac vacuum fuel feed system and tests using a pressure feed pump as an alternative. | 12th Dec 1925 | Box 40 \ 4 Scan157 | |
| Tests using a small vacuum pump to improve petrol supply efficiency. | 3rd Dec 1925 | Box 40 \ 4 Scan158 | |
| Test results table for Autovac supply and induction pipe depression on a 40/50 Silver Ghost at full throttle. | 9th May 1925 | Box 40 \ 4 Scan159 | |
| Table of results for Autovac tests on a 40/50 Silver Ghost, measuring supply rates against engine demand at various fuel levels. | 1st Dec 1925 | Box 40 \ 4 Scan160 | |
| Sketch of an Autovac Galometer and the delivery of tools. | 1st Dec 1925 | Box 40 \ 4 Scan161 | |
| The principle of action for the Autovac Galometer. | 9th Dec 1925 | Box 40 \ 4 Scan162 | |
| The workings of an Autovac petrol measurement instrument and its float chamber. | 21th Dec 1925 | Box 40 \ 4 Scan163 | |
| Describing the operation of a float chamber and reservoir system for a petrol supply. | 9th Dec 1925 | Box 40 \ 4 Scan164 | |
| The performance, error margins, and potential application of a Measuring Autovac and Galometer fuel system. | 9th Dec 1925 | Box 40 \ 4 Scan165 | |
| Comparing the specifications of a 'Measuring Autovac' with a 'Standard Autovac'. | 12th Jun 1925 | Box 40 \ 4 Scan166 | |
| Lead time and standardization of an improved elbow and modified suction valve for the Autovac system. | 31th Dec 1925 | Box 40 \ 4 Scan167 | |
| Cover letter forwarding a communication from R.R. Inc. concerning the Autovac for internal review and comments. | 5th Jan 1926 | Box 40 \ 4 Scan168 | |
| Experiment to compare a sample against an Autovac. | 7th Jan 1926 | Box 40 \ 4 Scan169 | |
| Attached document about the 'AUTOVAC'. | 4th Jan 1926 | Box 40 \ 4 Scan170 | |
| Letter suggesting using Stewart tank parts to resolve a misfiring issue with the Autovac system. | 22th Dec 1925 | Box 40 \ 4 Scan171 | |
| Comparing the performance of Stewart, Autovac, and Kingston fuel systems, detailing issues with misfiring. | 22th Dec 1925 | Box 40 \ 4 Scan172 | |
| Use of special oil pumps and vacuum systems, with reference to Cadillac and Stewart systems. | 22th Dec 1925 | Box 40 \ 4 Scan173 | |
| Recommending the standardisation of an improved bye-pass valve to resolve an ongoing fault with Autovac and slow running. | 1st Mar 1926 | Box 40 \ 4 Scan174 | |
| Ordering special elbows with a restricted valve to deal with complaints regarding the Autovac and faulty slow running. | 3rd Mar 1926 | Box 40 \ 4 Scan175 | |
| Standardisation of a special valve for the Autovac, intended to reduce negative effects on slow running. | 22th Apr 1926 | Box 40 \ 4 Scan176 | |
| The 40/50 HP Autovac, attaching a report for comment. | 21th Jun 1926 | Box 40 \ 4 Scan177 | |
| Instruction to use a soft aluminium washer on the 20 HP Autovac drain plug and induction pipe connection. | 20th Aug 1926 | Box 40 \ 4 Scan178 | |
| Petrol being sucked into the engine through the autovac pipe due to a piece of solder. | 8th Aug 1926 | Box 40 \ 4 Scan179 | |
| Test report on the 'IMCO' Autopulse fuel pump fitted to chassis 9-EX, comparing its performance and fuel level stability against the Autovac system. | 13th Sep 1926 | Box 40 \ 4 Scan180 | |
| The performance issues of the Autopulse unit, detailing its irregular petrol delivery and excessive noise. | 20th Sep 1926 | Box 40 \ 4 Scan181 | |
| Testing a modified piston valve for the Autovac petrol feed system to improve slow running. | 20th Sep 1926 | Box 40 \ 4 Scan182 | |
| Benefits of a parallel spindle over a tapered spindle in the Autovac system. | 13th Oct 1926 | Box 40 \ 4 Scan183 | |
| Issue with the plunger of the Autovac Restriction Elbow sticking due to a fine taper. | 13th Oct 1926 | Box 40 \ 4 Scan184 | |
| Sticking piston issue with the Autovac Restriction Elbow, contrasting a supplier's part with an in-house version. | 14th Oct 1926 | Box 40 \ 4 Scan185 | |
| Sample part from Autovac Co. and a proposed modification to a piston spindle. | 16th Oct 1926 | Box 40 \ 4 Scan186 | |
| Proposal to test a new aluminium head on a vacuum tank. | 16th Nov 1926 | Box 40 \ 4 Scan187 | |
| Cover note for a report detailing objections to the Autopulse Fuel Pump. | 22th Nov 1926 | Box 40 \ 4 Scan188 | |
| Action of the self-draining float in the Autovac petrol feed system. | 22th Dec 1926 | Box 40 \ 4 Scan189 | |
| Description of the action and design of a self-draining float for an Autovac petrol feed system. | 22th Dec 1926 | Box 40 \ 4 Scan190 | |
| The functionality and limitations of a self-draining float in an Autovac, including a diagram. | 30th Dec 1926 | Box 40 \ 4 Scan191 | |
| The potential causes for the Autovac petrol feed float overfilling and failing. | 30th Dec 1926 | Box 40 \ 4 Scan192 | |
| Query regarding a normal float and the potential effect of adding a restriction to its hollow stem. | 30th Dec 1926 | Box 40 \ 4 Scan193 | |
| Letter to Autovac Mfg. Co. Ltd. concerning significant variations in petrol delivery performance between different Autovac units. | 7th Jan 1927 | Box 40 \ 4 Scan194 | |
| Continued letter seeking information on the most efficient length of engine stroke. | 11th Jan 1927 | Box 40 \ 4 Scan195 | |
| Letter from Autovac Manufacturing Co. Ltd. acknowledging a previous correspondence and promising a follow-up after tests. | 11th Jan 1927 | Box 40 \ 4 Scan196 | |
| Letter to The Autovac Mfg. Co. Ltd. about persistent variation issues and a request for an expert to visit Derby. | 14th Jan 1927 | Box 40 \ 4 Scan197 | |
| Letter from The Autovac Manufacturing Co. Ltd. confirming a visit for 10 a.m. on Thursday the 20th. | 17th Jan 1927 | Box 40 \ 4 Scan198 | |
| Letter sending the results of Autovac tests to The Autovac Mfg. Co. Ltd. | 20th Jan 1927 | Box 40 \ 4 Scan199 | |
| Cross-sectional blueprint of a mechanical coupling or flange assembly. | 20th Jan 1927 | Box 40 \ 4 Scan200 | |
| Test report on petrol delivery variation by different autovac units under various conditions. | 20th Jan 1927 | Box 40 \ 4 Scan201 | |
| Comparative test results for alterations to a new type of autovac filter. | 20th Jan 1927 | Box 40 \ 4 Scan202 | |
| Autovac tests measuring the effect of restriction in the petrol line on petrol delivery under various conditions. | 20th Jan 1927 | Box 40 \ 4 Scan203 | |
| Autovac and dynamometer test results comparing different petrol filters. | 20th Jan 1927 | Box 40 \ 4 Scan204 | |
| Test report comparing the performance of original and modified autovac filters. | 21th Jan 1927 | Box 40 \ 4 Scan205 | |
| Letter from The Autovac Manufacturing Co. Ltd. acknowledging a report on Autovac tests and promising trial results. | 21th Jan 1927 | Box 40 \ 4 Scan206 | |
| Letter from Autovac Manufacturing Co. Ltd. discussing experiments on two fuel suction apparatus and a strainer. | 26th Jan 1927 | Box 40 \ 4 Scan207 | |
| Letter from The AutoVac Manufacturing Co. Ltd. detailing the results of experiments on petrol delivery systems. | 26th Jan 1927 | Box 40 \ 4 Scan208 | |
| Diagram illustrating the operation of an Autovac moving float mechanism. | 2nd Feb 1927 | Box 40 \ 4 Scan209 | |
| Cover page with a 'Print Room' stamp from Derby. | 2nd Feb 1927 | Box 40 \ 4 Scan210 | |
| Two types of Autovac petrol feed units received for testing to improve supply on the Phantom engine. | 2nd Feb 1927 | Box 40 \ 4 Scan211 | |
| Comparison of Measuring and Moving Float type Autovac fuel systems and their performance under different conditions. | 2nd Feb 1927 | Box 40 \ 4 Scan212 | |
| Report comparing the performance of different Autovac fuel system units and configurations. | 2nd Feb 1927 | Box 40 \ 4 Scan213 | |
| Analysis of an Autovac fuel system, detailing the effect of float movement on petrol delivery and cycle times. | 2nd Feb 1927 | Box 40 \ 4 Scan214 | |
| Investigation into petrol delivery variations in Autovacs, recommending a modification to the suction hole dimensions. | 2nd Feb 1927 | Box 40 \ 4 Scan215 | |
| Graph plotting Autovac petrol delivery against engine RPM in a series of comparison tests on a 20HP engine. | 8th Feb 1927 | Box 40 \ 4 Scan216 | |
| Blank page with a Print Room date stamp in the bottom right corner. | 8th Feb 1927 | Box 40 \ 4 Scan217 | |
| Graph comparing Autovac petrol delivery performance on a 20 HP engine at half throttle. | 2nd Feb 1927 | Box 40 \ 4 Scan218 | |
| Stamped by the print room in Derby. | 2nd Feb 1927 | Box 40 \ 4 Scan219 | |
| Graph showing the effect of Autovac float movement on petrol delivery against engine RPM. | 2nd Feb 1927 | Box 40 \ 4 Scan220 | |
| The reverse side of a document showing a Print Room date stamp. | 2nd Feb 1927 | Box 40 \ 4 Scan221 | |
| Letter to The Autovac Mfg. Co. detailing experiments on two of their Autovac units and suggesting future modifications. | 7th Feb 1927 | Box 40 \ 4 Scan222 | |
| Letter regarding modifications to Autovac units, the return of components for investigation, and enclosing comparative test results. | 16th Feb 1927 | Box 40 \ 4 Scan223 | |
| Occasional erratic working of the autovac due to issues with the float. | 16th Feb 1927 | Box 40 \ 4 Scan224 | |
| Sales trials for car GYK-10, detailing a fault with the autovac and subsequent carburetter adjustment. | 7th Feb 1927 | Box 40 \ 4 Scan225 | |
| Investigation into the cause of Autovac petrol feed failure, specifically testing scenarios related to a leaking float. | 2nd Feb 1927 | Box 40 \ 4 Scan226 | |
| Autovac failure analysis, specifically concerning the suction valve and float. | 7th Mar 1927 | Box 40 \ 4 Scan227 | |
| Legal dispute and patent case between Autovac and Grav-Vac. | 7th Mar 1927 | Box 40 \ 4 Scan228 | |
| Letter from Autovac Manufacturing Co. Ltd. regarding litigation over patent infringement of the Autovac apparatus. | 21th Dec 1925 | Box 40 \ 4 Scan229 | |
| Extract from a letter regarding the conclusion of litigation over a petrol feed apparatus patent. | 26th Feb 1927 | Box 40 \ 4 Scan230 | |
| Supply of Grav-Vac apparatus and detailing the legal history between the Grav-Vac and Autovac companies. | 9th Mar 1927 | Box 40 \ 4 Scan231 | |
| Report comparing the efficiency of the Grav-Vac vacuum petrol feed tank with the Autovac system. | 30th Mar 1927 | Box 40 \ 4 Scan232 | |
| Graph comparing the petrol delivery rates of Autovac and Grav-Vac fuel feed systems at different engine speeds. | 28th Mar 1927 | Box 40 \ 4 Scan233 | |
| Blank or heavily faded document with a purple stamp in the bottom right corner. | 30th Mar 1927 | Box 40 \ 4 Scan234 | |
| Unsatisfactory performance at slow speeds in cars fitted with the Autovac fuel system. | 7th Apr 1927 | Box 40 \ 4 Scan235 | |
| Known fault with the Autovac system on cars. | 7th Apr 1927 | Box 40 \ 4 Scan236 | |
| Letter from Autovac Mfg. Co. Ltd. regarding experiments on their apparatus and its effect on the fuel mixture. | 3rd Jul 1925 | Box 40 \ 4 Scan237 | |
| Requesting a report on the current opinion of the Autovac system's performance. | 8th Apr 1927 | Box 40 \ 4 Scan238 | |
| Attaching copies of two letters sent to the Autovac Co. regarding a problem. | 8th Apr 1927 | Box 40 \ 4 Scan239 | |
| Letter to the Autovac Mfg. Co. Ltd. regarding a complaint about slow speed light running issues with the 'Autovac' system. | 28th May 1925 | Box 40 \ 4 Scan240 | |
| Page 2 of a letter requesting suggestions to overcome an engine difficulty that occurs when warm. | 2nd Jul 1925 | Box 40 \ 4 Scan241 | |
| Letter to the Autovac Mfg. Co. Ltd. regarding an engine miss-fire issue caused by their system. | 2nd Jul 1925 | Box 40 \ 4 Scan242 | |
| Performance issues with the Autovac fuel system and requesting an updated opinion. | 1st Apr 1927 | Box 40 \ 4 Scan243 | |
| Complaint and subsequent alteration to the 'AUTOVAC' system. | 11th Apr 1927 | Box 40 \ 4 Scan244 | |
| Letter to The Autovac Co. regarding tests on modified suction elbows for an engine. | 29th Oct 1925 | Box 40 \ 4 Scan245 | |
| BJ to Hs concerning an Autovac and a letter to Mr. Gastall. | 12th Apr 1927 | Box 40 \ 4 Scan246 | |
| Letter regarding the ongoing unsatisfactory performance of the Autovac system and potential improvements. | 12th Apr 1927 | Box 40 \ 4 Scan247 | |
| Cover memo from BJ to Hs. enclosing correspondence with the Autovac Manufacturing Co. regarding the Autovac System. | 27th Apr 1927 | Box 40 \ 4 Scan248 | |
| Letter from Autovac Manufacturing Co. Ltd. to Rolls-Royce regarding the testing of their petrol feed system. | 26th Apr 1927 | Box 40 \ 4 Scan249 | |
| Letter to Mr. Gastall regarding improvements and defects in the Autovac System. | 27th Apr 1927 | Box 40 \ 4 Scan250 | |
| Fitting of an Autovac with a loose float to car 10-EX. | 27th Apr 1927 | Box 40 \ 4 Scan251 | |
| Carburettor starvation on the Phantom model, caused by petrol boiling in the Autovac fuel feed system. | 4th Jun 1927 | Box 40 \ 4 Scan252 | |
| Tests and solutions for petrol starvation in the autovac system due to heat from the exhaust manifold. | 14th Jun 1927 | Box 40 \ 4 Scan253 | |
| Failures of the autovac petrol feed system on Phantom cars and experiments to fix the issue using a larger pipe. | 14th Jun 1927 | Box 40 \ 4 Scan254 | |
| Test report on petrol pipe sizes for a Standard Phantom engine, recommending the adoption of a larger pipe. | 13th Jun 1927 | Box 40 \ 4 Scan255 | |
| Graph showing the effect of petrol pipe size on Autovac petrol delivery relative to engine RPM. | 13th Jun 1927 | Box 40 \ 4 Scan256 | |
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