| Description | Date | Identifier | |
| Exhaust roar issue, proposed solutions, and a decision not to purchase a Bentley car. | 11th Jul 1929 | Box 14 \ 6 Scan093 | |
| Query regarding the incorporation of modifications for Fabric Couplings and an S.S. Exhaust System into the first batch of S.S. chassis. | 15th Jul 1929 | Box 14 \ 6 Scan094 | |
| Laboratory report on pitting issues in S.S. exhaust valves and seatings due to the properties of Aluminium Bronze. | 16th Jul 1929 | Box 14 \ 6 Scan095 | |
| Test results for the S.S. chassis, focusing on axle performance, steering, and identified noise issues. | 16th Jul 1929 | Box 14 \ 6 Scan096 | |
| Exhaust manifold modifications, exhaust notes, and chassis testing results for various models. | 17th Jul 1929 | Box 14 \ 6 Scan097 | |
| Issues with exhaust valve seatings on S.S. cars, suggesting a change in material hardness. | 17th Jul 1929 | Box 14 \ 6 Scan098 | |
| Laboratory note discussing variations in the Brinell hardness of S.S. exhaust valve seatings. | 19th Jul 1929 | Box 14 \ 6 Scan099 | |
| Modifications to an SS exhaust system, including a new silencer design and reduced pipe diameter. | 26th Jul 1929 | Box 14 \ 6 Scan100 | |
| Differences for production cars regarding rear spring oiling, servo lining, thermostat, and exhaust fittings. | 26th Jul 1929 | Box 14 \ 6 Scan101 | |
| List of required modifications for S.S. cars concerning steering and damper components. | 30th Jul 1929 | Box 14 \ 6 Scan102 | |
| Mr. Royce's decisions on new materials for exhaust valves and valve guides for all engines. | 30th Jul 1929 | Box 14 \ 6 Scan103 | |
| Issue of spitting in the exhaust on the S.S. chassis. | 8th Aug 1929 | Box 14 \ 6 Scan104 | |
| Extract discussing a fault with the exhaust joint on an S.S. Chassis. | 1st Aug 1929 | Box 14 \ 6 Scan105 | |
| Oil leak issue with the change gear bracket breather hole and suggesting design modifications. | 14th Aug 1929 | Box 14 \ 6 Scan106 | |
| Modifications to an SS exhaust system, including a new scheme for a ribbed cast aluminium front expansion box. | 15th Aug 1929 | Box 14 \ 6 Scan107 | |
| Improvements to exhaust and inlet valves for all aero and car engines. | 19th Aug 1929 | Box 14 \ 6 Scan108 | |
| Modifications to an SS exhaust system box and its spring anchorage. | 20th Sep 1929 | Box 14 \ 6 Scan109 | |
| Various schemes for induction pipe and carburetter heating for the Phantom II model. | 1st Oct 1929 | Box 14 \ 6 Scan110 | |
| Programme of S.S. hot spot experiments and modifications for a 20 HP engine. | 16th Oct 1929 | Box 14 \ 6 Scan111 | |
| List of action items for modifying and testing engine components, including manifolds and compression ratios. | 16th Oct 1929 | Box 14 \ 6 Scan112 | |
| Calibration curve graph for an exhaust hot spot thermocouple. | 23th Oct 1929 | Box 14 \ 6 Scan113 | |
| Experiments with exhaust heating for the Phantom II engine's hot spot. | 23th Oct 1929 | Box 14 \ 6 Scan114 | |
| Page two of a test report discussing engine temperatures and the design of the exhaust and intake manifold. | 12th Nov 1929 | Box 14 \ 6 Scan115 | |
| Road test results of a cast aluminium silencer fitted to test car 20-EX. | 12th Nov 1929 | Box 14 \ 6 Scan116 | |
| Exhaust system modifications to reduce spitting noises and booming, including a cast aluminium part and a different down pipe. | 12th Nov 1929 | Box 14 \ 6 Scan117 | |
| Troubleshooting noise issues with the exhaust heated hot spot on the Phantom II. | 16th Nov 1929 | Box 14 \ 6 Scan118 | |
| Standardisation of chassis parts concerning Firth's Crown steel car engine exhaust valves. | 23th Aug 1929 | Box 14 \ 6 Scan119 | |
| Design to silence the noise in the Phantom II exhaust heated induction pipe. | 27th Nov 1929 | Box 14 \ 6 Scan120 | |
| Modification to the Phantom II exhaust silencer to prevent 'spitting'. | 28th Nov 1929 | Box 14 \ 6 Scan121 | |
| Design schemes for the Phantom II's exhaust-heated throttle. | 29th Nov 1929 | Box 14 \ 6 Scan122 | |
| Query regarding the supply of exhaust heated throttles for three Phantom II chassis exported to America. | 5th Dec 1929 | Box 14 \ 6 Scan123 | |
| Recommended exhaust heated throttle scheme for the Phantom II 18-EX car and the plan for its approval. | 6th Dec 1929 | Box 14 \ 6 Scan124 | |
| Brief acknowledgement memo regarding an exhaust heated throttle. | 7th Dec 1929 | Box 14 \ 6 Scan125 | |
| Querying the approval for fitting an exhaust-heated carburetter, particularly for cars destined for America. | 1st Dec 1929 | Box 14 \ 6 Scan126 | |
| Standardisation sheet for an exhaust heated bend for the Phantom II model, intended for cars going to the U.S.A. | 16th Dec 1929 | Box 14 \ 6 Scan127 | |
| Carburetter standardisation, Phantom II frame and carburetter development, and the 20 HP model. | 17th Dec 1929 | Box 14 \ 6 Scan128 | |
| Meeting notes on design modifications for the 20 HP and aero engines, including gearing and materials. | 2nd Jan 1930 | Box 14 \ 6 Scan129 | |
| Proposal to trial hard-drawn brass sheet for Phantom Chassis silencer laggings and clips as a cost-saving measure. | 2nd Jan 1930 | Box 14 \ 6 Scan130 | |
| Analysis comparing the standard silencer system with a new cast aluminium expansion box system for the Phantom II model. | 13th Jan 1930 | Box 14 \ 6 Scan131 | |
| Exhaust system tests, detailing power loss and component melting under test conditions. | 24th Nov 1930 | Box 14 \ 6 Scan132 | |
| Graph plotting Brake Horse Power against engine RPM for various exhaust system configurations on an SS-15 engine. | 9th Jan 1930 | Box 14 \ 6 Scan133 | |
| Blank page with a 'Print Room' stamp. | 13th Jan 1930 | Box 14 \ 6 Scan134 | |
| Graph showing power loss to a standard exhaust system for engine SS-15 under various configurations. | 9th Jan 1930 | Box 14 \ 6 Scan135 | |
| Blank document page marked with a 'Print Room' reception stamp. | 13th Jan 1930 | Box 14 \ 6 Scan136 | |
| Graph comparing the power output from an engine with different exhaust manifold pipe systems. | 10th Jan 1930 | Box 14 \ 6 Scan137 | |
| Page marked with a receiving stamp from the print room. | 13th Jan 1930 | Box 14 \ 6 Scan138 | |
| Blueprint diagram illustrating the failure of a cut-out ring, showing areas of melting and cracking. | 11th Mar 1930 | Box 14 \ 6 Scan139 | |
| Stamped document from the Print Room in Derby. | 14th Jan 1930 | Box 14 \ 6 Scan140 | |
| Modification to the Phantom II exhaust system's aluminium silencer to avoid drumming. | 28th Jan 1930 | Box 14 \ 6 Scan141 | |
| Phantom II exhaust system and a scheme for an aluminium front expansion box. | 28th Jan 1930 | Box 14 \ 6 Scan142 | |
| Effectiveness of a malleable iron feed pipe and the design of a silencer for a Phantom II induction system. | 1st Feb 1930 | Box 14 \ 6 Scan143 | |
| Vibrations and booms on the Phantom II model, caused by a leaking exhaust cutout valve, suggesting improvements. | 10th Feb 1930 | Box 14 \ 6 Scan144 | |
| Problems and proposed solutions for exhaust manifolds on various car models. | 26th Feb 1931 | Box 14 \ 6 Scan145 | |
| Manifold improvements for the P. 2 model, including material changes and the addition of cooling ribs. | 19th Mar 1930 | Box 14 \ 6 Scan146 | |
| Recommendation to delete drain holes in silencers as they are a source of exhaust noise. | 19th Mar 1930 | Box 14 \ 6 Scan147 | |
| Directive to revert to using S.L.V. steel for exhaust valves on 20 HP and 40/50 HP chassis. | 4th Apr 1930 | Box 14 \ 6 Scan148 | |
| The reversion to S.L.V. Specification No. 238.A for exhaust valves on 20/25 HP and 40/50 HP chassis. | 7th Apr 1930 | Box 14 \ 6 Scan149 | |
| The switch to S.L.V. steel for exhaust valves and the resulting scrap costs. | 8th Apr 1930 | Box 14 \ 6 Scan150 | |
| Investigation report on a seized exhaust cut out and a broken battery box flange on car 23-EX. | 24th Apr 1930 | Box 14 \ 6 Scan151 | |
| Issues with body mounting, subframes, and potential improvements. | 21th May 1930 | Box 14 \ 6 Scan152 | |
| Investigation into body and chassis noises like booming and rumble, with proposals for testing and modifications. | 21th May 1930 | Box 14 \ 6 Scan153 | |
| Bending of a triangular flat plate on the Phantom II exhaust system. | 28th May 1930 | Box 14 \ 6 Scan154 | |
| Slipping nickel silver lagging on the exhaust system of chassis 23-EX. | 2nd Jun 1930 | Box 14 \ 6 Scan155 | |
| Complaints of damage to spring gaiters from the Phantom II silencer outlet, with a proposed solution and a handwritten update. | 4th Jun 1930 | Box 14 \ 6 Scan156 | |
| The failure of a triangular stay for the Phantom II front exhaust box and proposed modifications. | 11th Aug 1930 | Box 14 \ 6 Scan157 | |
| With a sketch requesting an experimental, strengthened bracket for the front silencer. | 28th May 1930 | Box 14 \ 6 Scan158 | |
| Inquiring if it is in order to bend the Phantom II silencer snout to clear the gaiters. | 16th Jun 1930 | Box 14 \ 6 Scan159 | |
| Deterioration of ignition wires and the proposal to fit a shield. | 17th Jun 1930 | Box 14 \ 6 Scan160 | |
| Test report on two strengthened anchor plates for Phantom II exhaust fittings. | 20th Jun 1930 | Box 14 \ 6 Scan161 | |
| Extract from a report on tests of completed cars, regarding extending an exhaust pipe. | 26th Jun 1930 | Box 14 \ 6 Scan162 | |
| Alterations to the Phantom II silencer snout. | 4th Jul 1930 | Box 14 \ 6 Scan163 | |
| The failure of an aluminium front expansion box on an exhaust system and a request for a steel replacement. | 11th Jul 1930 | Box 14 \ 6 Scan164 | |
| Blueprint diagram illustrating the failure of a front expansion box. | 11th Jul 1930 | Box 14 \ 6 Scan165 | |
| Query regarding a collapsed front expansion chamber on a 24-EX Phantom II during a 10,000-mile test. | 14th Jul 1930 | Box 14 \ 6 Scan166 | |
| The failure of a modified aluminium exhaust system on a Phantom II car due to heat. | 14th Jul 1930 | Box 14 \ 6 Scan167 | |
| The non-standardisation of the 24-EX exhaust system and the unsuitability of aluminium. | 15th Jul 1930 | Box 14 \ 6 Scan168 | |
| Extract concerning the extension of the P.2. exhaust swan neck in relation to designing a rear apron. | 15th Jul 1930 | Box 14 \ 6 Scan169 | |
| Suggestion to increase the number of bolts on the P.2 exhaust system's front expansion box flange from 4 to 8. | 15th Jul 1930 | Box 14 \ 6 Scan170 | |
| The preferable steel and shape for exhaust valves in car and aero engines. | 13th Aug 1930 | Box 14 \ 6 Scan171 | |
| Failure of aluminium exhaust boxes and suggesting cast iron and other alloys as alternative materials. | 1st Aug 1930 | Box 14 \ 6 Scan172 | |
| Decision to manufacture ribbed exhaust boxes in cast iron. | 22th Aug 1930 | Box 14 \ 6 Scan173 | |
| From 'Sg.' to 'Hs.' requesting to be kept informed about the results regarding exhaust valves for car and aero engines. | 2nd Sep 1930 | Box 14 \ 6 Scan174 | |
| Responding to a proposal to alter exhaust valves, citing past negative experiences with Ostenetic Steel. | 3rd Sep 1930 | Box 14 \ 6 Scan175 | |
| Modification to the design of the Phantom II silencers. | 15th Oct 1930 | Box 14 \ 6 Scan176 | |
| Modifications to the petrol tank, single line gauge fitting, filler, wheel carrier, and exhaust fishtail. | 17th Nov 1930 | Box 14 \ 6 Scan177 | |
| Investigation into the cause and potential cure for 'spitting in the silencer'. | 20th Nov 1930 | Box 14 \ 6 Scan178 | |
| The effects of fitting a smaller low-speed choke tube to improve carburation and reduce engine spitting. | 20th Nov 1921 | Box 14 \ 6 Scan179 | |
| Engine tests performed on car 22-EX to investigate a 'spitting' issue. | 20th Nov 1939 | Box 14 \ 6 Scan180 | |
| The test results of a Phantom II exhaust system with a long sliding joint. | 1st Dec 1930 | Box 14 \ 6 Scan181 | |
| Revised bracket for the exhaust swanneck pipe and associated testing. | 1st Dec 1930 | Box 14 \ 6 Scan182 | |
| Changes and new parts for the Phantom II exhaust fittings. | 10th Dec 1930 | Box 14 \ 6 Scan183 | |
| New drawings and parts for an extended rear exhaust pipe experiment on a 40/50HP chassis. | 11th Dec 1930 | Box 14 \ 6 Scan184 | |
| The parts for a heat shield to be fitted to the exhaust manifold on a 40/50HP chassis. | 24th Dec 1930 | Box 14 \ 6 Scan185 | |
| Instruction to modify the exhaust system on all L.H. Phantom II chassis. | 7th Jan 1931 | Box 14 \ 6 Scan186 | |
| Standardisation report on altering the Phantom II exhaust system to the 20/25 scheme. | 11th Dec 1930 | Box 14 \ 6 Scan187 | |
| Implementation and costs associated with a standardized chassis part. | 2nd Feb 1931 | Box 14 \ 6 Scan188 | |
| 40/50 silencers, detailing power loss, weight, and silence level. | 2nd Feb 1931 | Box 14 \ 6 Scan189 | |
| Failure of an exhaust pipe due to corrosion and proposing further investigation on Phantom II chassis. | 3rd Feb 1931 | Box 14 \ 6 Scan190 | |
| Silencer pipe on a Phantom II failing due to intercrystalline corrosion, with a request to check other cars. | 5th Feb 1931 | Box 14 \ 6 Scan191 | |
| Use of cooling ribs on exhaust manifolds for Phantom I and 20/25 models. | 4th Mar 1931 | Box 14 \ 6 Scan192 | |
| | | | |