| Description | Date | Identifier | |
| Investigation into cracking of Phantom III fan blades and standardisation for the Phantom III & Wraith models. | 24th Oct 1938 | Box 94 \ 5 scan0077 | |
| Introduction of new Dural fan blades for the Phantom III and new blades for the Wraith. | 29th Oct 1938 | Box 94 \ 5 scan0078 | |
| Cracked Phantom III fan blade set and a request for new Duralumin blades to be fitted and sent to Messrs. Ferodo Ltd. | 28th Oct 1938 | Box 94 \ 5 scan0079 | |
| Requesting the preparation of a Phantom III fan with dural blades to be sent to Ferodo. | 9th Mar 1939 | Box 94 \ 5 scan0080 | |
| Request to build two Phantom III production fans with duralumin blades for belt testing due to a previous fan failure. | 28th Mar 1939 | Box 94 \ 5 scan0081 | |
| Request to despatch two Phantom III fans to Ferodo Ltd. for destructive testing. | 3rd Apr 1939 | Box 94 \ 5 scan0082 | |
| Requesting the urgent assembly of two Phantom III fan and spider assemblies for testing. | 10th May 1939 | Box 94 \ 5 scan0083 | |
| Requesting an investigation into the failure of a Phantom III fan spider. | 13th May 1939 | Box 94 \ 5 scan0084 | |
| Phantom III fan spider failure due to incorrect material specification. | 14th Jun 1939 | Box 94 \ 5 scan0085 | |
| Letter enclosing prints for the Phantom III fan drive pulley. | 7th Nov 1941 | Box 94 \ 5 scan0086 | |
| Design scheme for a cheaper fan and pulley assembly for Bentley and 25/30 models. | 1st Dec 1936 | Box 94 \ 5 scan0087 | |
| Requesting a quotation for 4 dozen Aerolite pistons for the Spectre engine. | 5th Jul 1934 | Box 94 \ 5 scan0088 | |
| Use of semi-split versus solid skirt pistons for the Spectre engine. | 8th Nov 1934 | Box 94 \ 5 scan0089 | |
| Request addressed to RHC for the manufacture of one set of Spectre pistons to B.V.42 specification. | 10th Nov 1934 | Box 94 \ 5 scan0090 | |
| Comparing the weights of pistons for Spectre and Bentley models. | 12th Nov 1934 | Box 94 \ 5 scan0091 | |
| Specification sheet detailing the measured diameters for new Aerolite pistons and cylinder bores. | 12th Nov 1934 | Box 94 \ 5 scan0092 | |
| Bedding of Spectre No. 2 pistons and requesting a modification for Spectre No. 5 pistons. | 13th Mar 1935 | Box 94 \ 5 scan0093 | |
| Cancelling previous instructions and providing new ones for grinding semi-split pistons. | 14th Mar 1935 | Box 94 \ 5 scan0094 | |
| Difficulty with Spectre pistons and the potential use of modified Bentley connecting rods. | 9th Apr 1935 | Box 94 \ 5 scan0095 | |
| Design of 'Spectre' pistons, proposing to base them on the existing 'Phantom' and '20/25' models for safety reasons. | 19th Jul 1935 | Box 94 \ 5 scan0096 | |
| Requesting the preparation of 12 Spectre pistons to be sent for grinding and use in a Bentley unit. | 5th Aug 1935 | Box 94 \ 5 scan0097 | |
| Request to fit new bushes to Spectre pistons due to them being too slack in the gudgeon pin bores. | 5th Aug 1935 | Box 94 \ 5 scan0098 | |
| Request for six Spectre Pistons with fitted bushes to be prepared for an endurance test in a B-2 unit. | 3rd Sep 1935 | Box 94 \ 5 scan0099 | |
| Endurance testing and issues with sand-cast Spectre pistons, proposing die-cast pistons as a solution. | 21th Oct 1935 | Box 94 \ 5 scan0100 | |
| Endurance test report on Spectre Fully Split Skirt Pistons. | 21th Oct 1935 | Box 94 \ 5 scan0101 | |
| Report comparing the oil consumption, power output, and weight of various piston designs. | 21th Oct 1935 | Box 94 \ 5 scan0102 | |
| Requesting a set of Spectre E.87347 die-cast pistons to be prepared for a C-10 unit. | 15th Nov 1935 | Box 94 \ 5 scan0103 | |
| Instructing the fitting of specific parts to a C-10 engine for Spectre piston tests. | 18th Nov 1935 | Box 94 \ 5 scan0104 | |
| Ordering, testing, and failures of steel skirted and Spectre pistons for the Phantom III engine. | 4th Dec 1935 | Box 94 \ 5 scan0105 | |
| Apologising for an error concerning the discussion of Steel Skirted Pistons for the Phantom III at conferences. | 16th Dec 1935 | Box 94 \ 5 scan0106 | |
| Recommendation to adopt slotted scraper piston rings for the Phantom III chassis. | 9th Dec 1935 | Box 94 \ 5 scan0107 | |
| Instruction to use slotted type scraper rings for the Phantom III chassis. | 18th Dec 1935 | Box 94 \ 5 scan0108 | |
| Issue with the Phantom III Gudgeon Pin marking cylinder walls and requesting a design change. | 20th Dec 1935 | Box 94 \ 5 scan0109 | |
| Alterations to the Phantom III gudgeon pin pads. | 21th Dec 1935 | Box 94 \ 5 scan0110 | |
| Alterations and new drawings for the Phantom III Chassis piston. | 3rd Jan 1936 | Box 94 \ 5 scan0111 | |
| Continued note on specifications for gudgeon pin end pieces and slotted rings. | 3rd Jan 1936 | Box 94 \ 5 scan0112 | |
| The 10,000-mile test for the Phantom III piston development to address piston knock. | 3rd Feb 1936 | Box 94 \ 5 scan0113 | |
| Proposal to fit new pistons and liners to the 34-EX engine and future plans for an experimental engine. | 3rd Feb 1936 | Box 94 \ 5 scan0114 | |
| Phantom III piston development, specifically the design of the piston skirt. | 10th Feb 1936 | Box 94 \ 5 scan0115 | |
| Ongoing development and testing of pistons and liners for the Phantom III engine. | 8th Feb 1936 | Box 94 \ 5 scan0116 | |
| Log of piston, ring, and rocker shaft work performed on various chassis numbers. | 25th Mar 1936 | Box 94 \ 5 scan0117 | |
| The 2000-mile test run of a new set of Phantom III pistons, including dismantling for inspection. | 25th Mar 1936 | Box 94 \ 5 scan0118 | |
| Requesting figures on existing Bentley rings to order new high unit pressure rings for the Spectre engine to prevent overoiling. | 6th Apr 1936 | Box 94 \ 5 scan0119 | |
| Request to prepare 24 Phantom III pistons for grinding by Light Production Co. Ltd. | 27th Apr 1936 | Box 94 \ 5 scan0120 | |
| Issues with broken Phantom III piston rings and recommending new gap specifications. | 7th Aug 1936 | Box 94 \ 5 scan0121 | |
| Not proceeding with the LeC.5221 3-ring piston with ring stops for the Phantom III. | 12th Aug 1936 | Box 94 \ 5 scan0122 | |
| Alteration of the Phantom III Piston Ring gap to manage supplier costs. | 19th Oct 1936 | Box 94 \ 5 scan0123 | |
| Technical memo regarding a new high compression piston design for the Phantom lll. | 23th Dec 1938 | Box 94 \ 5 scan0124 | |
| Recommendation to replace the standard Phantom III top piston rings due to breakage. | 27th Feb 1939 | Box 94 \ 5 scan0125 | |
| Steering improvements for the 'Spectre' model, comparing it to American cars and considering independently sprung wheels. | 10th Nov 1932 | Box 95 \ 1 scan0126 | |
| Improvements in suspension, braking, and steering, referencing competitor cars. | 10th Nov 1932 | Box 95 \ 1 scan0127 | |
| Internal memorandum discussing the removal of the gland on the Spectre steering shaft. | 27th Apr 1934 | Box 95 \ 1 scan0128 | |
| Steering connections and ball joints for the Spectre model. | 24th May 1934 | Box 95 \ 1 scan0129 | |
| The Spectre steering connections, referencing plan N. Sch.4055 and noting further information to follow. | 24th May 1934 | Box 95 \ 1 scan0130 | |
| 'Spectre' model's steering connections and related schematics. | 26th May 1934 | Box 95 \ 1 scan0131 | |
| The layout plan for the Spectre side steering tube and connections. | 30th May 1934 | Box 95 \ 1 scan0132 | |
| Proposed modification to the Spectre model's steering pendulum lever for increased clearance. | 8th Jun 1934 | Box 95 \ 1 scan0133 | |
| Proposal for applying centralised chassis lubrication to the Spectre's cross steering tube end and brake camshaft. | 8th Jun 1934 | Box 95 \ 1 scan0134 | |
| Design change for the Spectre side steering tube ball joint due to clearance issues. | 30th Jun 1934 | Box 95 \ 1 scan0135 | |
| Issues with the 'Spectre Steering' system, comparing it to the Phantom and suggesting modifications to increase friction. | 6th Sep 1934 | Box 95 \ 1 scan0136 | |
| Order for 12 springs for a Spectre cross steering tube. | 21th Sep 1934 | Box 95 \ 1 scan0137 | |
| Steering experiment on the 'Spectre' car, changing the pendulum lever from 6' to 9'. | 3rd Oct 1934 | Box 95 \ 1 scan0138 | |
| Steering tube springs and initial load for the 'Spectre' model. | 5th Oct 1934 | Box 95 \ 1 scan0139 | |
| Design of the Spectre steering system, comparing it with Marles and La Salle steering. | 16th Nov 1934 | Box 95 \ 1 scan0140 | |
| Efficiency and manufacturing of steering gear for the Spectre model, comparing it to La Salle and Marles designs. | 16th Nov 1934 | Box 95 \ 1 scan0141 | |
| The mechanical efficiency of a Marles Type L.7 Steering Gear for a 25 HP vehicle. | 15th Nov 1934 | Box 95 \ 1 scan0142 | |
| Mechanical efficiency tests on a Marles Type L.7 Steering Gear on Chassis 21-G-IV. | 15th Nov 1934 | Box 95 \ 1 scan0143 | |
| The limitations of the Marles type steering gear's pendulum lever. | 15th Nov 1934 | Box 95 \ 1 scan0144 | |
| Relaying a telegram with the helix angle for Cadillac steering and comparing its performance to the LaSalle steering. | 22th Nov 1934 | Box 95 \ 1 scan0145 | |
| The design and production of the Spectre model's steering column. | 28th Nov 1934 | Box 95 \ 1 scan0146 | |
| Development of a steering system for the Spectre, referencing Cadillac and La Salle designs. | 3rd Dec 1934 | Box 95 \ 1 scan0147 | |
| The Spectre steering column, referencing scheme N. Sch.4281 for the Marles type steering. | 4th Dec 1934 | Box 95 \ 1 scan0148 | |
| The design principles for 'Spectre Steering', focusing on eliminating friction and improving stability. | 4th Dec 1934 | Box 95 \ 1 scan0149 | |
| Correcting a scheme number for the Spectre Steering Column. | 7th Dec 1934 | Box 95 \ 1 scan0150 | |
| Experimental department report on Spectre steering. | 10th Dec 1934 | Box 95 \ 1 scan0151 | |
| Steering tests conducted on the Spectre, comparing it with Cadillac and LaSalle systems. | 10th Dec 1934 | Box 95 \ 1 scan0152 | |
| Steering and suspension adjustments made to correct oversteer and handling issues on a car. | 10th Dec 1934 | Box 95 \ 1 scan0153 | |
| Steering tests conducted on the 27-EX model to correct high speed wobble and jellying. | 10th Dec 1934 | Box 95 \ 1 scan0154 | |
| Test report comparing the number of steering wheel turns required over a 12-mile run under different car configurations. | 10th Dec 1934 | Box 95 \ 1 scan0155 | |
| Test results table for various Independent Front Wheel Suspension (I.F.W.S.) steering configurations. | 10th Dec 1934 | Box 95 \ 1 scan0156 | |
| Data table comparing original steering geometry with the effects of rolling the car, under varying applied torque. | 10th Dec 1934 | Box 95 \ 1 scan0157 | |
| Trial of a new steering gear for the Spectre model to correct oversteering. | 10th Dec 1934 | Box 95 \ 1 scan0158 | |
| Design modifications to the Spectre-Marles type steering column with the Adamant Engineering Co. | 12th Dec 1934 | Box 95 \ 1 scan0159 | |
| Alternative proposals for the cam roller bearings on the Spectre - Marles type Steering Column. | 14th Dec 1934 | Box 95 \ 1 scan0160 | |
| Spectre steering column support and a gas-tight seal at the floorboards. | 3rd Jan 1935 | Box 95 \ 1 scan0161 | |
| Mechanical efficiency of the Marles Steering gear for Spectre, providing a reason for a drop in efficiency and comparing component weights. | 3rd Apr 1935 | Box 95 \ 1 scan0162 | |
| The efficiency and testing of the Marles Steering gear for the Spectre model. | 3rd Apr 1935 | Box 95 \ 1 scan0163 | |
| Fitting Marles-Spectre steering into a 20/25 chassis. | 8th Apr 1935 | Box 95 \ 1 scan0164 | |
| Secret memo regarding the support brackets for the Spectre steering on the 20/25 model, referencing a Bentley design. | 10th Apr 1935 | Box 95 \ 1 scan0165 | |
| Spectre Marles Steering geometry for the 20/25 Chassis, referencing drawing N.Sch.4454. | 13th Apr 1935 | Box 95 \ 1 scan0166 | |
| Two new designs for Spectre steering controls and requesting wooden models be made. | 2nd May 1935 | Box 95 \ 1 scan0167 | |
| Secret memo discussing the suggestion to use Timken taper rollers for the Spectre-Marles type steering. | 10th May 1935 | Box 95 \ 1 scan0168 | |
| Comparing Marles and La Salle steering systems on Spectre models regarding road shocks and slack, with requests for measurement and adjustment. | 29th May 1935 | Box 95 \ 1 scan0169 | |
| The Spectre Marles Steering, agreeing to supply parts to Adamant Engineering Co. and requesting a demonstration model be built. | 4th Jun 1935 | Box 95 \ 1 scan0170 | |
| Secret memorandum detailing a modification to Spectre steering ball end bushes, changing the material from hardened steel to bronze. | 5th Jun 1935 | Box 95 \ 1 scan0171 | |
| The Spectre steering box for testing Marles cams and rollers and its proposed use on the 25 HP model. | 6th Jun 1935 | Box 95 \ 1 scan0172 | |
| Secret memo regarding a modification to the Spectre's Cross Steering Lever for additional clearance. | 7th Jun 1935 | Box 95 \ 1 scan0173 | |
| The supply and modification of a Marles steering system for the Spectre I vehicle. | 18th Jun 1935 | Box 95 \ 1 scan0174 | |
| Supplier's recommendation to use steel instead of brass for roller bearing cages in a Spectre Marles Type Steering system. | 21th Jun 1935 | Box 95 \ 1 scan0175 | |
| Request for an official order to be sent to Adamant Engineering Co. for two special cams for experimental purposes. | 21th Jun 1935 | Box 95 \ 1 scan0176 | |
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