| Description | Date | Identifier | |
| Addition of a coolant jet to the cylinder block for the Car Universal Unit with a high power head. | 3rd Nov 1936 | Box 134 \ 2 scan0088 | |
| The replacement of an exhaust valve for a high power head cylinder block, including material and dimensional changes. | 3rd Nov 1936 | Box 134 \ 2 scan0089 | |
| Visit to Coventry Climax Engines Ltd. to discuss the O.H.1 engine design, covering cylinder head form, plug position, and throat size. | 9th Nov 1936 | Box 134 \ 2 scan0090 | |
| Comparative analysis of engine design features, including valves, temperatures, ignition, and cooling, with reference to Coventry Climax engines. | 9th Nov 1936 | Box 134 \ 2 scan0091 | |
| Engine development issues concerning gaskets, inlet valve height, induction passages, and tests on an 8:1 compression ratio engine. | 9th Nov 1936 | Box 134 \ 2 scan0092 | |
| Poor car performance, cylinder head material considerations, and patent litigation concerning O.H.1 type engines. | 10th Nov 1936 | Box 134 \ 2 scan0093 | |
| Modifications to a high-power cylinder head and block, including a list of required parts. | 10th Nov 1936 | Box 134 \ 2 scan0094 | |
| Visit to Coventry Climax Engine Co. regarding high power cylinder head design. | 11th Nov 1936 | Box 134 \ 2 scan0095 | |
| Cylinder head design, combustion chamber characteristics, and engine performance tests. | 11th Nov 1936 | Box 134 \ 2 scan0096 | |
| The performance figures and design of a four-cylinder Skinner engine tested by Coventry Climax. | 11th Nov 1936 | Box 134 \ 2 scan0097 | |
| The supply of prints for a larger inlet valve (RS.317) for a High Power Head universal unit. | 11th Nov 1936 | Box 134 \ 2 scan0098 | |
| Investigation into throat areas on high power cylinder heads to explain performance differences. | 8th Dec 1936 | Box 134 \ 2 scan0099 | |
| Design of an inclined inlet valve high-power cylinder head for a single-cylinder unit. | 19th Nov 1936 | Box 134 \ 2 scan0100 | |
| Modifications to the cylinder block, piston, and inlet valve dimensions. | 12th Feb 1937 | Box 134 \ 2 scan0101 | |
| Cover note for a table on the cost and weight of units, detailing potential cost increases for alternative casting methods. | 12th Feb 1937 | Box 134 \ 2 scan0102 | |
| Comparative table of five different engine construction types, analyzing weight, cost, and design remarks. | 16th Feb 1937 | Box 134 \ 2 scan0103 | |
| Progress memo on the development of an overhead inlet side valve exhaust unit, detailing issues and findings. | 16th Feb 1937 | Box 134 \ 2 scan0104 | |
| The pros and cons of a monobloc engine design with a cast iron crankcase and an aluminium head. | 16th Feb 1937 | Box 134 \ 2 scan0105 | |
| Difficulties with an O.H.V. unit and the potential move to 12-cylinder or Vee-type engines. | 16th Feb 1937 | Box 134 \ 2 scan0106 | |
| Power output tests of a High Power Head for a Bentley engine, comparing results and showing percentage gains. | 16th Feb 1937 | Box 134 \ 2 scan0107 | |
| Performance graph comparing a high power head against a standard 3 1/2 litre Bentley engine on a water brake dynamometer. | 13th Feb 1937 | Box 134 \ 2 scan0108 | |
| Dynamometer graph comparing a high power head against a standard 3 1/2 litre Bentley engine. | 13th Feb 1937 | Box 134 \ 2 scan0109 | |
| Graph comparing the performance curves of standard and high-power Bentley engine units. | 13th Feb 1937 | Box 134 \ 2 scan0110 | |
| Comparative efficiency of American car engines and the need to test exhaust system losses. | 31th May 1937 | Box 134 \ 2 scan0111 | |
| Engine policy, comparing overhead, side valve, and push rod engines with reference to American designs. | 31th May 1937 | Box 134 \ 2 scan0112 | |
| Producing an economical car, considering side-valve engines and referencing competitor performance. | 31th May 1937 | Box 134 \ 2 scan0113 | |
| Performance comparison graph of the 25/30 HP engine against American engines (Buick and Terraplane). | 1st Jan 1937 | Box 134 \ 2 scan0114 | |
| Performance comparison graphs for typical 1937 side-valve engines, and for Buick and Chrysler 8-cylinder engines. | 1st Jan 1937 | Box 134 \ 2 scan0115 | |
| Performance graph comparing the Brake Mean Effective Pressure (B.M.E.P.) of Bentley engines against American engines under different exhaust conditions. | 1st Jan 1937 | Box 134 \ 2 scan0116 | |
| Two graphs comparing the BMEP of 1937/1938 Buick and Oldsmobile engines. | 1st Jan 1937 | Box 134 \ 2 scan0117 | |
| Graph comparing the top gear acceleration of a 25/30 HP Saloon car against an Oldsmobile Eight Saloon car. | 31th May 1937 | Box 134 \ 2 scan0118 | |
| Comparison data of a No.2 High Power Head and a Standard Bentley Head for constant detonation. | 31th May 1937 | Box 134 \ 2 scan0119 | |
| Performance graph comparing a high power head against a standard Bentley head for the same detonation intensity. | 20th Aug 1937 | Box 134 \ 2 scan0120 | |
| Progress report on the single-cylinder development of an Overhead Inlet Side Valve Exhaust engine. | 20th Aug 1937 | Box 134 \ 2 scan0121 | |
| Power comparison report between a high power inclined valve head and a standard 3.5 litre Bentley. | 9th Jul 1937 | Box 134 \ 2 scan0122 | |
| Graph comparing performance against R.P.M. for different cylinder head, valve timing, and compression ratio configurations under constant detonation. | 9th Jul 1937 | Box 134 \ 2 scan0123 | |
| Comparative performance graph showing Torque and M.E.P. curves for Bentley, Oldsmobile, and a 30 HP RR engine. | 1st Jul 1937 | Box 134 \ 2 scan0124 | |
| Graph comparing B.M.E.P. against R.P.M. for different high-power head configurations. | 1st Jul 1937 | Box 134 \ 2 scan0125 | |
| Resource allocation and the urgent need for design work on a single-cylinder high power head unit. | 27th Aug 1937 | Box 134 \ 2 scan0126 | |
| Programme outlining tests and modifications for a single-cylinder unit, focusing on back pressure and camshaft design. | 27th Aug 1937 | Box 134 \ 2 scan0127 | |
| Proposed modifications and tests for engine valve gear and valve seats. | 14th Jul 1937 | Box 134 \ 2 scan0128 | |
| Outlining proposed engine component modifications and testing requirements. | 31th Aug 1937 | Box 134 \ 2 scan0129 | |
| Secret memo detailing modifications for the Phoenix combustion chamber, specifically adapting the LeC.5368 high power head. | 31th Aug 1937 | Box 134 \ 2 scan0130 | |
| Differential thermal expansion in a high-powered engine with an aluminium head and cast iron block. | 2nd Sep 1937 | Box 134 \ 2 scan0131 | |
| Brief report on the development of a high-power engine head, detailing issues and recommendations. | 23th Aug 1937 | Box 134 \ 2 scan0132 | |
| Blueprint graph of ignition advance curves against engine RPM for different cylinder head designs. | 11th Aug 1937 | Box 134 \ 2 scan0133 | |
| Graph of detonation intensity versus RPM for four different high power head configurations. | 10th Aug 1937 | Box 134 \ 2 scan0134 | |
| Blueprint showing the arrangement of a coolant jet in high power blocks. | 10th Aug 1937 | Box 134 \ 2 scan0135 | |
| Engine detonation tests comparing different cylinder head materials, valve types, and ignition settings. | 23th Aug 1937 | Box 134 \ 2 scan0136 | |
| Power comparison graph for different high power head configurations at constant detonation. | 19th Aug 1937 | Box 134 \ 2 scan0137 | |
| Engine performance report on plug position, power output, and detonation tests. | 23th Aug 1937 | Box 134 \ 2 scan0138 | |
| The development and testing of inlet and exhaust valves, including different types, timing and bounce issues. | 23th Aug 1937 | Box 134 \ 2 scan0139 | |
| Graph comparing power output (BHP) and BMEP for different cylinder head configurations against engine RPM. | 20th Aug 1937 | Box 134 \ 2 scan0140 | |
| Graph plotting B.M.E.P. against back pressure for back pressure tests at 4000 R.P.M. | 9th Aug 1937 | Box 134 \ 2 scan0141 | |
| Engine valve and timing tests to address detonation and improve power output on a Bentley engine. | 23th Aug 1937 | Box 134 \ 2 scan0142 | |
| Power comparison graph of three different cylinder head designs, plotting B.M.E.P. and Main Engine B.HP against R.P.M. | 20th Aug 1937 | Box 134 \ 2 scan0143 | |
| The testing of various cylinder heads, cylinder blocks, and an analysis of slow running performance. | 23th Aug 1937 | Box 134 \ 2 scan0144 | |
| Engine component failures and their running hours. | 23th Jun 1937 | Box 134 \ 2 scan0145 | |
| General conclusions on engine head development, covering gaskets, cooling, valves, and timing. | 23th Aug 1937 | Box 134 \ 2 scan0146 | |
| Technical memorandum discussing valve gear design, back pressure issues, and cylinder head development. | 23th Aug 1937 | Box 134 \ 2 scan0147 | |
| Photograph and details of the No. 2 high power block with an exhaust valve. | 23th Aug 1937 | Box 134 \ 2 scan0148 | |
| Photograph of the No.1 High Power Head, showing the combustion chamber, and its associated inlet valve. | 23th Aug 1937 | Box 134 \ 2 scan0149 | |
| Photograph of a No.1 high power block with an exhaust valve. | 23th Aug 1937 | Box 134 \ 2 scan0150 | |
| Photograph of the No.2 High Power Block with details on its construction. | 23th Aug 1937 | Box 134 \ 2 scan0151 | |
| Photograph of a No.2 High Power Head and its corresponding inlet valve. | 23th Aug 1937 | Box 134 \ 2 scan0152 | |
| Photograph of a high power aluminium cylinder head with an inserted valve seat and a separate inlet valve. | 23th Aug 1937 | Box 134 \ 2 scan0153 | |
| Photograph and details of the No. 4 High Power Head. | 12th Oct 1937 | Box 134 \ 2 scan0154 | |
| Lighter valve gear mechanism on the new main engine head and its expected performance. | 12th Oct 1937 | Box 134 \ 2 scan0155 | |
| Index of memos regarding high power cylinder head development. | 27th May 1935 | Box 134 \ 2 scan0156 | |
| Index page listing technical reports with their subjects, reference numbers, and circulation lists from 1935-1936. | 31th May 1935 | Box 134 \ 2 scan0157 | |
| Index page of internal memos and instructions from October and November 1936. | 9th Oct 1936 | Box 134 \ 2 scan0158 | |
| Index page listing reports with their reference numbers, subjects, and circulation lists. | 15th Oct 1937 | Box 134 \ 2 scan0159 | |
| History and progress of the High Power Cylinder Head Project. | 15th Oct 1937 | Box 134 \ 2 scan0160 | |
| Progress and costs of a High Power engine head project and single-cylinder work. | 15th Oct 1937 | Box 134 \ 2 scan0161 | |
| Uncovered aero figure from the previous year and the scale of single cylinder work. | 15th Oct 1937 | Box 134 \ 2 scan0162 | |
| Visit to Coventry Climax Engines Ltd. to gather information on an O.H.I. type engine. | 16th Oct 1937 | Box 134 \ 2 scan0163 | |
| Report discussing engine detonation, ignition advance, and spark plug positioning. | 16th Oct 1937 | Box 134 \ 2 scan0164 | |
| Report discussing engine performance, including spark plug reach, valve overlap, engine breathing, and exhaust valve temperature. | 16th Oct 1937 | Box 134 \ 2 scan0165 | |
| Report discussing design considerations for engine valves and ports, including temperature, shape, and cooling. | 16th Oct 1937 | Box 134 \ 2 scan0166 | |
| Diagrams of an O.H.C. 3 Litre Coventry Climax and a Ricardo Venturi Inlet Port. | 18th Oct 1937 | Box 134 \ 2 scan0167 | |
| Letter to Coventry Climax Engines Ltd. requesting a list of engine part weights. | 18th Oct 1937 | Box 134 \ 2 scan0168 | |
| Letter discussing a list and declining to share information on the latest O.H.1 cylinder head. | 18th Oct 1937 | Box 134 \ 2 scan0169 | |
| Thank you letter to Leonard P. Lee of Coventry Climax Engines Ltd for a list of weights and an update on O.H.1 head tests. | 2nd Dec 1937 | Box 134 \ 2 scan0170 | |
| Cover note discussing a weight analysis comparison between a Coventry Climax engine and a Bentley engine for the High Power Unit project. | 1st Dec 1934 | Box 134 \ 2 scan0171 | |
| List of weights for the components of a 2-litre type JGS engine with a fully counterweighted, completely machined crankshaft. | 1st Dec 1934 | Box 134 \ 2 scan0172 | |
| Weight calculation sheet for engine components from Coventry Climax Engines Ltd. | 20th Dec 1937 | Box 134 \ 2 scan0173 | |
| Valve timing tests for high power single-cylinder units and proposals for future development, including a new cylinder head. | 20th Dec 1937 | Box 134 \ 2 scan0174 | |
| Proposed modifications and allowances for engine components including metal thickness and throat area. | 20th Dec 1937 | Box 134 \ 2 scan0175 | |
| Follow-up memo requesting the status on the matter of a High Power Cylinder Head. | 31th Jan 1938 | Box 134 \ 2 scan0176 | |
| The suspension of a single-cylinder project and the design status of a less costly engine for Phoenix. | 1st Feb 1938 | Box 134 \ 2 scan0177 | |
| Confirming an agreement to start a new high power unit at the same size as the 4.5-litre Bentley. | 22th Feb 1938 | Box 134 \ 2 scan0178 | |
| Secret memo discussing competitor engine projects from Morris Motors and Vauxhall, and urging the completion of drawings for a new high-power engine. | 29th Apr 1938 | Box 134 \ 2 scan0179 | |
| Requesting a cylinder head with a 7½:1 compression ratio and flat top pistons for a High Power engine test. | 5th Oct 1938 | Box 134 \ 2 scan0180 | |
| Secret memo outlining preliminary cost and weight savings for a new high-power engine unit. | 26th Oct 1938 | Box 134 \ 2 scan0181 | |
| Engine power improvements and experimental variations of the High Power Head Project, including proposals for a Straight Eight and 5-litre Six-cylinder engine. | 26th Oct 1938 | Box 134 \ 2 scan0182 | |
| The merits and costs of an aluminium Straight Eight engine compared to a cast iron version. | 26th Oct 1938 | Box 134 \ 2 scan0183 | |
| Power output graph for a 4¼ Litre Bentley engine, comparing two different compression ratios. | 15th Dec 1938 | Box 134 \ 2 scan0184 | |
| Design and development tasks for a high power cylinder head. | 15th Dec 1938 | Box 134 \ 2 scan0185 | |
| Progress report on the B.60 engine test, comparing novel modifications to the conventional 4¼-litre engine. | 9th Feb 1939 | Box 134 \ 2 scan0186 | |
| The unsolved problems of developing a harmonic damper and a crank pinion spring drive for an engine. | 9th Feb 1939 | Box 134 \ 2 scan0187 | |
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