| Description | Date | Identifier | |
| Instruction to modify a standard Bentley crankshaft by drilling additional holes to improve bearing lubrication. | 8th Jan 1937 | Box 85 \ 5 scan0125 | |
| Crankshaft failure at the flywheel flange and analysis of related failures. | 19th Feb 1937 | Box 85 \ 5 scan0126 | |
| Blueprint detailing a crankshaft failure, showing test results, running time, and views of the broken component. | 19th Feb 1937 | Box 85 \ 5 scan0127 | |
| Crankshaft forgings for the 25/30-HP and Bentley 'L' Series chassis. | 9th Mar 1937 | Box 85 \ 5 scan0128 | |
| Testing and standardisation of crankshafts for 25/30 & Bentley models. | 12th Mar 1937 | Box 85 \ 5 scan0129 | |
| Confirming the decision not to standardise larger crankshafts for the 25/30 HP and Bentley chassis at the present time. | 15th Mar 1937 | Box 85 \ 5 scan0130 | |
| The method of recovering worn or bowed nitrided crankshafts. | 6th Nov 1936 | Box 85 \ 5 scan0131 | |
| Report on a crankshaft flange failure. | 17th Jun 1937 | Box 85 \ 5 scan0132 | |
| Failure of a Bentley crankshaft due to an unsatisfactory nitriding process, resulting in insufficient hardness. | 2nd Dec 1937 | Box 85 \ 5 scan0133 | |
| Diameter and tightening of cylinder head studs for the Peregrine and Bensport engines. | 4th Jun 1932 | Box 86 \ 1 scan0001 | |
| Technical analysis of engine cylinder head stud stress and design considerations. | 6th Jun 1932 | Box 86 \ 1 scan0002 | |
| Cylinder head nuts for Peregrine & Bensfort engines, debating stud size and materials. | 6th Jun 1932 | Box 86 \ 1 scan0003 | |
| Material and design considerations for Bensport Cylinder Studs. | 6th Jun 1932 | Box 86 \ 1 scan0004 | |
| Drawing LeC.3115 for a cylinder head, valves, and rocker gear for the Bensport and Peregrine engines. | 13th Jun 1932 | Box 86 \ 1 scan0005 | |
| Sanctioning a trial of a cylinder head having six exhaust and six inlet ports for the Peregrine & Bensport engine. | 15th Jun 1932 | Box 86 \ 1 scan0006 | |
| Investigation into cylinder stud and gasket failures on a supercharged Peregrine engine for the 'Bensport' project. | 22th Sep 1932 | Box 86 \ 1 scan0007 | |
| Stress analysis and comparison data for Kestrel and Bensport engine studs. | 22th Sep 1932 | Box 86 \ 1 scan0008 | |
| Confirmation of a telephone message regarding issues and improvements for the Peregrine & Bensport engine head joint. | 26th Sep 1932 | Box 86 \ 1 scan0009 | |
| Design points and improvements for an engine, including valves, gaskets, and cooling. | 1st Oct 1932 | Box 86 \ 1 scan0010 | |
| Proposal to modify a cylinder block for a Bensport cylinder head. | 1st Oct 1932 | Box 86 \ 1 scan0011 | |
| Modifications to the Bensport cylinder head following testing. | 13th Jan 1933 | Box 86 \ 1 scan0012 | |
| Reminding about an unresolved issue with the Bensport cylinder head and piston alignment. | 16th Feb 1933 | Box 86 \ 1 scan0013 | |
| The machining of a J.1 cylinder head casting for a Bensport car. | 27th Feb 1933 | Box 86 \ 1 scan0014 | |
| Cylinder head modifications for the 'Bensport' model, including trepanning and combustion space depth reduction. | 28th Feb 1933 | Box 86 \ 1 scan0015 | |
| Potential incorrect assembly of the Bensport Rocker Shaft's central pedestal and proposing a modification to prevent it. | 21th Apr 1933 | Box 86 \ 1 scan0016 | |
| Modifications to the Bensport Cylinder Head to increase the compression ratio. | 13th May 1933 | Box 86 \ 1 scan0017 | |
| Listing technical drawings for the Bensport water by-pass regulator and noting an alteration to the water drain cock. | 13th May 1933 | Box 86 \ 1 scan0018 | |
| Required capacity for altered Bentley engine head castings to achieve the correct compression ratio. | 19th May 1933 | Box 86 \ 1 scan0019 | |
| Instructing modifications to a cylinder head for larger valves and higher compression ratios. | 7th Jun 1933 | Box 86 \ 1 scan0020 | |
| Three proposed experiments on a Bentley cylinder head to improve power output. | 19th Jun 1933 | Box 86 \ 1 scan0021 | |
| Modifications to the inlet valve and cylinder head for 'Bensport' power output. | 21th Jun 1933 | Box 86 \ 1 scan0022 | |
| Blueprint for a modified Bentley Cylinder Head to improve airflow. | 14th Jul 1933 | Box 86 \ 1 scan0023 | |
| Standardisation and testing of Bentley engine compression ratios. | 26th Jul 1933 | Box 86 \ 1 scan0024 | |
| Measurement data for three different cylinder heads. | 26th Jul 1933 | Box 86 \ 1 scan0025 | |
| Failed Cylinder Head Gasket from a 3.5 Litre Bentley engine. | 31th Jul 1933 | Box 86 \ 1 scan0026 | |
| Requesting modifications to a Bentley cylinder head for larger valves and an increased compression ratio. | 11th Sep 1933 | Box 86 \ 1 scan0027 | |
| Design changes and specifications for an experimental Bentley aluminium cylinder head. | 28th Sep 1933 | Box 86 \ 1 scan0028 | |
| Blueprint LeC.3662, detailing an experimental cast iron head for a Bentley. | 7th Oct 1933 | Box 86 \ 1 scan0029 | |
| Request for wooden models of a Bensport cylinder head to conduct air flow tests. | 21th Oct 1933 | Box 86 \ 1 scan0030 | |
| Design change to the Bentley Aluminium Cylinder Head valve seating angle. | 1st Nov 1933 | Box 86 \ 1 scan0031 | |
| Exhaust valve seats for car engines, referencing data from aero engine tests. | 7th Nov 1933 | Box 86 \ 1 scan0032 | |
| Outlining the design points for experimental exhaust valve seats for a Bentley aluminium cylinder head. | 7th Nov 1933 | Box 86 \ 1 scan0033 | |
| Blueprint for an exhaust valve seat. | 7th Nov 1933 | Box 86 \ 1 scan0034 | |
| Promising preliminary test results of a new cylinder head design (LEG.3673) using a wooden model. | 1st Dec 1933 | Box 86 \ 1 scan0035 | |
| Addition to a report on tests for the valving efficiency of F.II A Bentley engines, comparing cylinder heads. | 30th Nov 1933 | Box 86 \ 1 scan0036 | |
| Air flow pressure difference tests conducted on various wooden and standard cylinder head models, with and without cylinder barrels attached. | 30th Nov 1933 | Box 86 \ 1 scan0037 | |
| Summary comparing flow improvements between different head designs using wooden models. | 30th Nov 1933 | Box 86 \ 1 scan0038 | |
| Graph comparing airflow curves for three different types of Bentley cylinder heads. | 30th Nov 1933 | Box 86 \ 1 scan0039 | |
| Graph showing the effect of a cylinder barrel's presence on air flow and comparing two different cylinder head models. | 30th Nov 1933 | Box 86 \ 1 scan0040 | |
| Graph comparing airflows with standard and increased valve lifts against pressure difference for a Bentley head model. | 30th Nov 1933 | Box 86 \ 1 scan0041 | |
| Blueprint showing a cross-section of a valve assembly and guide. | 4th Dec 1933 | Box 86 \ 1 scan0042 | |
| Promising preliminary tests of a new cylinder head and inquiring about patent status. | 4th Dec 1933 | Box 86 \ 1 scan0043 | |
| Responding to an inquiry about the patent status of Cylinder Head Lec.3673. | 5th Dec 1933 | Box 86 \ 1 scan0044 | |
| Tests analysing differences in flow between wooden models and actual machined castings for Phantom II & Bentley engine valving. | 6th Dec 1933 | Box 86 \ 1 scan0045 | |
| Conclusions and summary of tests on engine head modifications, including streamlining ports and adjusting the inlet valve. | 6th Dec 1933 | Box 86 \ 1 scan0046 | |
| Graph comparing various Bentley cylinder heads by air-flow tests. | 7th Dec 1933 | Box 86 \ 1 scan0047 | |
| Comparison of airflow properties for three different Bentley cylinder head designs. | 7th Dec 1933 | Box 86 \ 1 scan0048 | |
| Graph comparing air flow versus pressure difference for various Bentley cylinder head designs. | 13th Dec 1933 | Box 86 \ 1 scan0049 | |
| Performance testing of a higher compression cylinder head for a Bentley engine. | 13th Dec 1933 | Box 86 \ 1 scan0050 | |
| The purchase of a J.A.P. motorcycle cylinder head for research into combustion chamber design and volumetric efficiency. | 21th Dec 1933 | Box 86 \ 1 scan0051 | |
| Requesting the simultaneous completion of aluminium and cast-iron Bentley high-compression cylinder heads for comparative testing of detonation characteristics. | 4th Jan 1934 | Box 86 \ 1 scan0052 | |
| Requesting an experimental report on corrugated sheet metal cylinder head gaskets for potential use on the Spectre engine. | 13th Jan 1934 | Box 86 \ 1 scan0053 | |
| Comparison of high compression aluminium and cast iron cylinder heads. | 22th Mar 1934 | Box 86 \ 1 scan0054 | |
| Report comparing the detonation characteristics and Mean Effective Pressure (M.E.P.) of aluminium versus cast iron cylinder heads. | 10th Mar 1934 | Box 86 \ 1 scan0055 | |
| Performance graph comparing different Bentley cylinder heads, showing Brake Horsepower and B.M.E.P. against R.P.M. | 10th Mar 1934 | Box 86 \ 1 scan0056 | |
| Graph comparing the compression pressure of Aluminium vs. Cast Iron cylinder heads on a Bentley B.A.A. unit. | 10th Mar 1938 | Box 86 \ 1 scan0057 | |
| Performance comparison graph for Aluminium versus Cast Iron Bentley cylinder heads. | 10th Mar 1938 | Box 86 \ 1 scan0058 | |
| Graph comparing the performance of Aluminium and Cast Iron cylinder heads for a Bentley unit, measuring B.M.E.P against R.P.M. | 19th Mar 1934 | Box 86 \ 1 scan0059 | |
| The testing and modification of a Bentley aluminium cylinder head. | 25th Apr 1934 | Box 86 \ 1 scan0060 | |
| Higher compression cylinder heads for the Bentley, concluding a 7:1 ratio is the limit. | 15th May 1934 | Box 86 \ 1 scan0061 | |
| The testing and performance of high compression cylinder heads for Bentley engines. | 15th May 1934 | Box 86 \ 1 scan0062 | |
| Power output and valve timing diagram for a 3 1/2 Litre Bentley engine. | 12th Feb 1923 | Box 86 \ 1 scan0063 | |
| Graph of I.M.E.P. & B.M.E.P. curves for various pistons against R.P.M. | 20th Feb 1934 | Box 86 \ 1 scan0064 | |
| Performance graph comparing different Bentley cylinder head configurations, materials, and compression ratios. | 9th Mar 1934 | Box 86 \ 1 scan0065 | |
| Request for work to conduct experiments comparing the roughness of 20/25 HP and Bentley cylinder heads. | 28th May 1934 | Box 86 \ 1 scan0066 | |
| Modifications for Bentley Cylinder Heads. | 5th Jun 1934 | Box 86 \ 1 scan0067 | |
| Request to produce a high compression cylinder head for a Bentley. | 7th Jun 1934 | Box 86 \ 1 scan0068 | |
| Modifications to the Aluminium Bentley Cylinder Head, specifically the use of steel washers and new collars for double valve springs. | 21th Jun 1934 | Box 86 \ 1 scan0069 | |
| Modification to the gudgeon pin plug, introducing a conical end based on the Bentley design. | 27th Jun 1934 | Box 86 \ 1 scan0070 | |
| The design, performance and potential alterations of the Bentley gudgeon pin plug. | 2nd Jul 1934 | Box 86 \ 1 scan0071 | |
| Tendency for Bentley gudgeon pin buttons to work loose due to insufficient taper, with a request to produce new sets. | 2nd Jul 1934 | Box 86 \ 1 scan0072 | |
| Instruction to modify a Bentley cylinder head (EB.1237) by machining the face to reduce capacity. | 17th Jul 1934 | Box 86 \ 1 scan0073 | |
| Request for a print of the valve gear scheme for a Bentley 'Power' Head to estimate its performance. | 24th Jul 1934 | Box 86 \ 1 scan0074 | |
| Letter from Wills Pressure Filled Joint Ring, Ltd. offering their patented pressure filled joint rings for testing. | 25th Jul 1934 | Box 86 \ 1 scan0075 | |
| Promotional leaflet for 'Magister Pressuum' pressure-filled joint rings. | 25th Jul 1934 | Box 86 \ 1 scan0076 | |
| Illustrations of various applications for Wills Pressure Filled Rings and Joints. | 25th Jul 1934 | Box 86 \ 1 scan0077 | |
| Data sheet for the Wills Pressure Filled Joint Ring, including a performance graph and patent information. | 7th Dec 1932 | Box 86 \ 1 scan0078 | |
| Preface and test conclusions for the Wills Patent Pressure Filled Joint Ring, with compression load graphs for copper and monel metal rings. | 7th Dec 1932 | Box 86 \ 1 scan0079 | |
| Test results and historical information on the Wills Patent Pressure Filled Joint Ring. | 12th Oct 1932 | Box 86 \ 1 scan0080 | |
| The compression and internal pressure testing of three Monel metal rings. | 12th Oct 1932 | Box 86 \ 1 scan0081 | |
| Steam jointing materials with diagrams of a joint blowing-out apparatus and an application of a pressure-filled joint ring. | 10th Aug 1932 | Box 86 \ 1 scan0082 | |
| The blowing out test of Wills Pressure Filled Joint Rings, with details of a test piece from the British Industries Fair. | 10th Aug 1932 | Box 86 \ 1 scan0083 | |
| National Physical Laboratory report on compression and blowing out tests for Wills Pressure Filled Joint Rings. | 10th Aug 1932 | Box 86 \ 1 scan0084 | |
| Instructions and diagrams for fitting various types of permanent and semi-permanent joint assemblies and rings for piping. | 10th Aug 1932 | Box 86 \ 1 scan0085 | |
| Fitting instructions and technical details for 'Wills' pressure-filled joint rings. | 10th Aug 1932 | Box 86 \ 1 scan0086 | |
| The applications of a patent pressure-filled joint ring and a patent renewable seat wheel valve. | 30th Jul 1934 | Box 86 \ 1 scan0087 | |
| Letter to Wills Pressure Filled Joint Ring Ltd. enclosing a blueprint for a Bentley Cylinder Head Gasket and requesting pressure rings for testing. | 30th Jul 1934 | Box 86 \ 1 scan0088 | |
| Letter from Wills Pressure Filled Joint Ring, Ltd. regarding the production of joint rings and gaskets for a Bentley cylinder head. | 31th Jul 1934 | Box 86 \ 1 scan0089 | |
| Letter to Wills Pressure Filled Joint Ring, Ltd. requesting the cost of a Copper Gasket with rings. | 2nd Aug 1934 | Box 86 \ 1 scan0090 | |
| Letter from Wills Pressure Filled Joint Ring, Ltd. regarding the supply of patent pressure filled copper gaskets. | 14th Aug 1934 | Box 86 \ 1 scan0091 | |
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