| Description | Date | Identifier | |
| Design preference for the Spectre's bonnet eye on the dash. | 2nd Jul 1934 | Box 92 \ 6 scan0258 | |
| Lightened form of Amal bonnet fastener for Spectre bonnets, with a suggested modification to the handle bearing. | 14th Jul 1934 | Box 92 \ 6 scan0259 | |
| Instruction to use a Bentley type bonnet eye on the Spectre dashboard due to fitting difficulties. | 21th Aug 1934 | Box 92 \ 6 scan0260 | |
| Suggesting a modification to the Spectre model's bonnet rest to avoid weakening it at the radiator end. | 29th Aug 1934 | Box 92 \ 6 scan0261 | |
| The louvered bonnet drawing for the third Spectre chassis. | 22th Feb 1935 | Box 92 \ 6 scan0262 | |
| Requesting the fitting of bonnet locks to the Spectre vehicle. | 7th May 1935 | Box 92 \ 6 scan0263 | |
| Secret memorandum regarding the urgent fitting of a temporary bonnet lock to the experimental Spectre cars. | 9th May 1935 | Box 92 \ 6 scan0264 | |
| Bonnet design specifications for the Spectre model, covering different angles, shutters, and louvres. | 14th Jun 1935 | Box 92 \ 6 scan0265 | |
| Request to manufacture a louvered bonnet for a 'Spectre' model for testing purposes. | 12th Aug 1935 | Box 92 \ 6 scan0266 | |
| The provisional design of bonnet locks for the Spectre model, including details for demonstration cars. | 5th Sep 1935 | Box 92 \ 6 scan0267 | |
| Experimental job on Spectre under-bonnet temperatures, using thermostatically operated shutters. | 10th Sep 1935 | Box 92 \ 6 scan0268 | |
| Requesting a design change for the Phantom III bonnet louvres to match a drawing from Messrs. Barkers. | 1st Oct 1935 | Box 92 \ 6 scan0269 | |
| Tests conducted on thermostatically controlled bonnet shutters on a Phantom III and a Lincoln car. | 1st Jan 1936 | Box 92 \ 6 scan0270 | |
| Conclusions and summary on the effectiveness and control of thermostatic bonnet shutters for engine cooling. | 1st Jan 1936 | Box 92 \ 6 scan0271 | |
| Duplication of a shuttered bonnet for Chassis 3-AZ-70, referencing Chassis 34-EX for details. | 22th Apr 1936 | Box 92 \ 6 scan0272 | |
| Providing the drawing number for the 7° Sloping Bonnet. | 25th Apr 1936 | Box 92 \ 6 scan0273 | |
| High under-bonnet temperatures and a proposal for a new cooling system design separating engine temperature control from radiator shutter operation. | 29th Oct 1936 | Box 92 \ 6 scan0274 | |
| Engine cooling systems, radiator shutters, and under-bonnet temperature control, with proposed modifications for the Phantom III. | 29th Oct 1936 | Box 92 \ 6 scan0275 | |
| The benefits of an independent shutter control scheme to reduce average vehicle temperatures. | 12th Nov 1936 | Box 92 \ 6 scan0276 | |
| Under-bonnet temperature readings and the design progress of a thermostatic unit for shutter control. | 12th Nov 1936 | Box 92 \ 6 scan0277 | |
| Wider bonnet rest strip fabric for car 35-EX and a related query for a Bentley strip. | 17th Dec 1936 | Box 92 \ 6 scan0278 | |
| Complaints and suggested improvements for the Phantom III bonnets. | 31th Dec 1936 | Box 92 \ 6 scan0279 | |
| Sketch showing a proposed bonnet support mechanism in open and closed positions. | 5th Mar 1937 | Box 92 \ 6 scan0280 | |
| Confirming the standardisation of shutters for the Phantom III bonnet side panels. | 5th Mar 1937 | Box 92 \ 6 scan0281 | |
| The design and production of Phantom III bonnets using standard 25/30 HP shutters. | 5th Mar 1937 | Box 92 \ 6 scan0282 | |
| Requesting modification of a chassis drawing for Phantom III bonnets. | 8th Mar 1937 | Box 92 \ 6 scan0283 | |
| The fitting of shutters to the new standard Phantom III bonnet. | 9th Mar 1937 | Box 92 \ 6 scan0284 | |
| Experimental modification to the Phantom III bonnet and scuttle fitting to correct irregularities. | 10th Mar 1937 | Box 92 \ 6 scan0285 | |
| Test results and the procedure for fitting bonnets to the Wraith III model. | 23th Mar 1937 | Box 92 \ 6 scan0286 | |
| Experiment to mount the bonnet off the scuttle instead of the dash on the 36-EX car. | 23th Mar 1937 | Box 92 \ 6 scan0287 | |
| Requesting the fabrication of two sets of Phantom III bonnet rest angles with wider lacing strips. | 21th Apr 1937 | Box 92 \ 6 scan0288 | |
| Issue with the bonnet rest angle preventing radiator removal on the P.XII model. | 27th Apr 1937 | Box 92 \ 6 scan0289 | |
| Suggestion to reduce under-bonnet temperature on the Phantom III by using the flywheel as an extraction fan. | 31th May 1937 | Box 92 \ 6 scan0290 | |
| Under-bonnet airflow issues and potential solutions for engine cooling. | 31th May 1937 | Box 92 \ 6 scan0291 | |
| Suggestion to reduce under-bonnet temperature on the Phantom III by modifying the flywheel and casing to act as an extractor fan. | 31th May 1937 | Box 92 \ 6 scan0292 | |
| Dispatch of a Phantom III bonnet and instructions for its fitting. | 17th Jun 1937 | Box 92 \ 6 scan0293 | |
| Modification request for the Phantom 111 Bonnet Rest Plate and Angle Brackets. | 30th Aug 1937 | Box 92 \ 6 scan0294 | |
| Instructing the fitting of a special Ferodo bonnet rest strip to car 32-EX. | 14th Jan 1938 | Box 92 \ 6 scan0295 | |
| Power losses in the Phantom and Spectre exhaust systems and the development of a larger silencer. | 24th Sep 1934 | Box 93 \ 1 scan0001 | |
| Spectre exhaust system, proposing a new silencer to address power loss issues. | 24th Sep 1934 | Box 93 \ 1 scan0002 | |
| Preliminary figures for an exhaust system and a newly designed silencer undergoing testing. | 8th Oct 1934 | Box 93 \ 1 scan0003 | |
| Test results for engine performance under four different exhaust system configurations. | 8th Oct 1934 | Box 93 \ 1 scan0004 | |
| Design and testing of Spectre exhaust manifolds, proposing fabricated prototypes before finalizing a cast design. | 5th Nov 1934 | Box 93 \ 1 scan0005 | |
| Arrangement diagram for the exhaust fittings and ground clearances of the Spectre model. | 2nd Nov 1934 | Box 93 \ 1 scan0006 | |
| Test report on an experimental Spectre exhaust system and proposals for modifying the silencer. | 5th Dec 1934 | Box 93 \ 1 scan0007 | |
| Power loss on the Spectre exhaust system. | 5th Dec 1934 | Box 93 \ 1 scan0008 | |
| Performance graph comparing Brake Horsepower vs RPM for different Spectre II exhaust systems. | 4th Dec 1934 | Box 93 \ 1 scan0009 | |
| Blueprint for a large resonant silencer for the Spectre. | 24th Nov 1934 | Box 93 \ 1 scan0010 | |
| Instruction to manufacture and fit a new front expansion box for an exhaust system. | 9th Jan 1935 | Box 93 \ 1 scan0011 | |
| Requesting the manufacture and fitting of a modified oval swan neck exhaust pipe for a 30-EX model. | 10th Jan 1935 | Box 93 \ 1 scan0012 | |
| Comparison of performance between original and modified Spectre exhaust manifolds. | 7th Feb 1935 | Box 93 \ 1 scan0013 | |
| Graph comparing the performance of different exhaust manifolds on a Spectre No. 1 unit. | 7th Feb 1935 | Box 93 \ 1 scan0014 | |
| Re-designed exhaust manifold for the Spectre model, detailing its improvements. | 11th Mar 1935 | Box 93 \ 1 scan0015 | |
| Request to have redesigned 'Spectre' exhaust manifolds made and fitted to the 30-EX car, Loc.4408. | 27th Mar 1935 | Box 93 \ 1 scan0016 | |
| Testing the Spectre Exhaust System, detailing efforts to reduce 'tinniness' using rope lagging. | 24th Apr 1935 | Box 93 \ 1 scan0017 | |
| Using lagging to reduce 'tinniness' and requesting suggestions to improve the system without increasing weight. | 24th Apr 1935 | Box 93 \ 1 scan0018 | |
| New 'Spectre Exhaust System' blueprint, proposing a test with a larger manifold to reduce 'tittering' noises. | 28th May 1935 | Box 93 \ 1 scan0019 | |
| Secret memorandum regarding an experimental Spectre exhaust manifold modification. | 22th Jun 1935 | Box 93 \ 1 scan0020 | |
| Request to cast three additional exhaust manifolds for test bed endurance work before the pattern is altered. | 8th Jul 1935 | Box 93 \ 1 scan0021 | |
| With annotations regarding the exhaust tail pipe length on the Spectre model. | 8th Jul 1935 | Box 93 \ 1 scan0022 | |
| Secret memo detailing a modification for the No.3 Spectre silencer to increase its flow area. | 12th Jul 1935 | Box 93 \ 1 scan0023 | |
| Instructing on modifications for Spectre exhaust systems due to power loss issues. | 6th Aug 1935 | Box 93 \ 1 scan0024 | |
| Secret memo detailing a minor modification to the Spectre Silencer to improve exhaust flow. | 29th Aug 1935 | Box 93 \ 1 scan0025 | |
| Sending drawing LeC.4640, which details a silencer lagged with sheet asbestos. | 14th Sep 1935 | Box 93 \ 1 scan0026 | |
| Specifications for modifying the exhaust silencer on the Spectre II car. | 16th Sep 1935 | Box 93 \ 1 scan0027 | |
| List of modifications for the Spectre Exhaust Silencer system. | 25th Sep 1935 | Box 93 \ 1 scan0028 | |
| Instruction to fit the Finned Exhaust manifold E.86817 to Phantom III cars for production. | 4th Oct 1935 | Box 93 \ 1 scan0029 | |
| Instruction to place an order with Metallisation Ltd. for aluminising a Phantom III exhaust tail pipe. | 24th Apr 1936 | Box 93 \ 1 scan0030 | |
| Letter to Metallisation Ltd. regarding the aluminising of a Phantom III exhaust tail pipe. | 24th Apr 1936 | Box 93 \ 1 scan0031 | |
| Squeaking exhaust systems and the preference for a simpler rubber mounting solution. | 25th May 1936 | Box 93 \ 1 scan0032 | |
| Issues with exhaust system rattles and squeaks, proposing a rubber suspension solution. | 10th Jun 1936 | Box 93 \ 1 scan0033 | |
| Photographs of three different designs for metal mounting brackets. | 12th Jun 1936 | Box 93 \ 1 scan0034 | |
| Proposal to test aluminised mild steel exhaust systems to reduce costs on Phantom III and 25/30 chassis. | 12th Jun 1936 | Box 93 \ 1 scan0035 | |
| Requesting the fitting of aluminized mild steel exhaust components to Phantom III and 25/30 HP cars. | 16th Jun 1936 | Box 93 \ 1 scan0036 | |
| Cost comparison of spherical pads for the exhaust system from Gandy and Ferodo. | 24th Jun 1936 | Box 93 \ 1 scan0037 | |
| Use of Aluminized mild steel instead of Staybright for exhaust silencers on Phantom II and 25/30 HP models. | 28th Aug 1936 | Box 93 \ 1 scan0038 | |
| Methods to improve the Phantom III exhaust system to reduce boom at 30 M.P.H. | 31th Aug 1936 | Box 93 \ 1 scan0039 | |
| Alternative, cheaper filter element for the Phantom III Air Silencer. | 25th Sep 1936 | Box 93 \ 1 scan0040 | |
| Requesting information on which car specific exhaust system spherical pads, sent to France, were fitted to. | 29th Sep 1936 | Box 93 \ 1 scan0041 | |
| Technical note discussing modifications to ignition timing and other issues for car 37-EX. | 5th Oct 1936 | Box 93 \ 1 scan0042 | |
| Modification to the Phantom III exhaust system to address an exhaust drone. | 13th Oct 1936 | Box 93 \ 1 scan0043 | |
| Complications with the Phantom III exhaust system and proposing a modified approach. | 26th Oct 1936 | Box 93 \ 1 scan0044 | |
| Modifications to the Phantom III exhaust system, including a new tail pipe and rubber mounting. | 26th Oct 1936 | Box 93 \ 1 scan0045 | |
| Instruction regarding a modified tail pipe and suspension for the Phantom III exhaust system. | 26th Oct 1936 | Box 93 \ 1 scan0046 | |
| Material cost savings for the Phantom III exhaust system. | 31th Oct 1936 | Box 93 \ 1 scan0047 | |
| Requesting a modified tail pipe and suspension be fitted to a Phantom III car. | 3rd Nov 1936 | Box 93 \ 1 scan0048 | |
| Request to modify the Phantom III exhaust system on the experimental vehicle 37-EX. | 7th Nov 1936 | Box 93 \ 1 scan0049 | |
| The manufacture of plain exhaust manifolds for a Phantom III for testing purposes. | 12th Nov 1936 | Box 93 \ 1 scan0050 | |
| Modifications to the Phantom III exhaust system to reduce weight and cost. | 12th Nov 1936 | Box 93 \ 1 scan0051 | |
| Design recommendation to mount the rear silencer further back to reduce exhaust noise, noting a limitation on the Phantom III car. | 12th Nov 1936 | Box 93 \ 1 scan0052 | |
| Requesting the fabrication of two seam-welded tubes for a Phantom III exhaust system. | 12th Nov 1936 | Box 93 \ 1 scan0053 | |
| Status update on the Phantom III C.Series Exhaust System, detailing production hold-ups. | 13th Nov 1936 | Box 93 \ 1 scan0054 | |
| Instruction to fit a new type of rear silencer and aluminized exhaust system to a car. | 14th Nov 1936 | Box 93 \ 1 scan0055 | |
| Methods of protection for the exhaust system against corrosion and scaling. | 16th Nov 1936 | Box 93 \ 1 scan0056 | |
| Requesting a programme of tests for an exhaust system to ensure a smooth transition into production. | 13th Nov 1936 | Box 93 \ 1 scan0057 | |
| Exhaust boom issue and drone at 30 m.p.h. on chassis GUL-1. | 26th Nov 1936 | Box 93 \ 1 scan0058 | |
| Requesting the substitution of a document concerning 'Exhaust Boom - GUL-1'. | 26th Nov 1936 | Box 93 \ 1 scan0059 | |
| Exhaust boom issue on vehicle GUL-1 and a potential solution. | 26th Nov 1936 | Box 93 \ 1 scan0060 | |
| Designs and materials for a revised Phantom III exhaust system. | 26th Nov 1936 | Box 93 \ 1 scan0061 | |
| Request to remove engine torque re-action dampers from vehicle 32-EX for mounting experiments. | 28th Nov 1936 | Box 93 \ 1 scan0062 | |
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