| Description | Date | Identifier | |
| Letter to Crossley Motors Ltd. regarding arrangements for a works visit. | 4th Jul 1934 | Box 133 \ 2 scan0045 | |
| Dispatch note from Rudge-Whitworth for a 4.99 HP Ulster engine, complete with carburetter and magneto. | 4th Jul 1934 | Box 133 \ 2 scan0046 | |
| Technical memorandum discussing performance improvements of a single-cylinder car unit, comparing Kestrel and Bentley components. | 4th Jul 1934 | Box 133 \ 2 scan0047 | |
| Volumetric efficiency, anti-detonating characteristics, and proposed blowing tests on engine models. | 4th Jul 1934 | Box 133 \ 2 scan0048 | |
| Comparison of Kestrel and Bentley ramp heads, showing performance curves and valve area data. | 4th Jul 1934 | Box 133 \ 2 scan0049 | |
| Letter from Rudge-Whitworth Limited regarding the dispatch of a 500 c.c. racing engine for experimental purposes. | 4th Jul 1934 | Box 133 \ 2 scan0050 | |
| Letter from 'Successors to Rudge Whitworth Ltd.' explaining the difficulty in measuring pipe length for dynamometer testing. | 5th Jul 1934 | Box 133 \ 2 scan0051 | |
| Letter to Rudge-Whitworth Limited regarding a delay in engine testing due to a lack of a suitable brake. | 5th Jul 1934 | Box 133 \ 2 scan0052 | |
| Follow-up letter to Norton Motors Ltd. regarding a previous unanswered letter. | 5th Jul 1934 | Box 133 \ 2 scan0053 | |
| Request to remove the head of a Rudge engine to measure valve sizes for an Air Ministry inspection. | 6th Jul 1934 | Box 133 \ 2 scan0054 | |
| Letter from Crossley Motors Ltd. confirming a meeting with Mr. W.A. Robotham. | 6th Jul 1934 | Box 133 \ 2 scan0055 | |
| Letter to H.R. Ricardo discussing cylinder head designs from Crossley's, their similarity to Ricardo's own, and planned single-cylinder tests. | 11th Jul 1934 | Box 133 \ 2 scan0056 | |
| Requesting an official report on single cylinder development. | 13th Jul 1934 | Box 133 \ 2 scan0057 | |
| Letter from Harry Ricardo discussing a 'High Power Head' patent from a competitor named Whatmough and Ricardo's own successful patent action. | 13th Jul 1934 | Box 133 \ 2 scan0058 | |
| Report comparing a 'Ramp' type cylinder head with a standard Bentley head on a single-cylinder test unit. | 26th Jul 1934 | Box 133 \ 2 scan0059 | |
| Comparison of 'Ramp' and standard cylinder heads, detailing constructional differences and detonation test setup. | 26th Jul 1934 | Box 133 \ 2 scan0060 | |
| Performance comparison between the 'Ramp' cylinder head and the standard head, focusing on detonation and power output. | 26th Jul 1934 | Box 133 \ 2 scan0061 | |
| Analysis of engine performance based on modifications to choke size, valve lift, timing, and exhaust valve size. | 26th Jul 1934 | Box 133 \ 2 scan0062 | |
| Engine test results, including power loss, supercharged tests, and various mechanical failures. | 26th Jul 1934 | Box 133 \ 2 scan0063 | |
| Engine valve mechanism issues, proposed solutions, and future work on cylinder head design and performance testing. | 26th Jul 1934 | Box 133 \ 2 scan0064 | |
| Graph comparing the performance of Ramp and Standard cylinder heads in Bentley single-cylinder tests. | 26th Jul 1934 | Box 133 \ 2 scan0065 | |
| Graph showing detonation tests with a Ramp Cylinder Head, plotting BMEP and ignition advance against RPM. | 26th Jul 1934 | Box 133 \ 2 scan0066 | |
| Detonation tests on a Bentley single cylinder engine with a standard cylinder head. | 26th Jul 1934 | Box 133 \ 2 scan0067 | |
| Graph comparing the power performance of Ramp and Standard cylinder heads on a Bentley single-cylinder test engine using normal fuel. | 26th Jul 1934 | Box 133 \ 2 scan0068 | |
| Power comparison chart for Ramp and Standard cylinder heads from Bentley single-cylinder tests, using anti-detonating fuel. | 26th Jul 1934 | Box 133 \ 2 scan0069 | |
| Graph comparing the indicated power and consumption of Ramp and Standard cylinder heads for Bentley single cylinder tests. | 1st Nov 1937 | Box 133 \ 2 scan0070 | |
| Graph comparing the effect of choke size variation on BMEP for a Ramp Head versus a Standard Head in Bentley single cylinder tests. | 1st Nov 1937 | Box 133 \ 2 scan0071 | |
| Graph comparing performance with different exhaust valve sizes and timings on a Bentley single cylinder head. | 1st Jul 1937 | Box 133 \ 2 scan0072 | |
| Graph showing supercharged power curves from Bentley single cylinder engine tests with a ramp head. | 1st Jul 1937 | Box 133 \ 2 scan0073 | |
| Correction notice for a report on the Single Cylinder Bentley Unit, instructing the recipient to substitute incorrect curves. | 2nd Aug 1934 | Box 133 \ 2 scan0074 | |
| Urgent requirements and status for a single-cylinder Bentley engine project. | 3rd Aug 1934 | Box 133 \ 2 scan0075 | |
| Comparing the No.2 Ramp Cylinder Head with a Standard Bentley head. | 24th Oct 1934 | Box 133 \ 2 scan0076 | |
| Single cylinder Bentley unit, comparing the performance and detonation characteristics of a revised 'Ramp' cylinder head against the standard version. | 11th Oct 1934 | Box 133 \ 2 scan0077 | |
| Detailed report comparing the performance of standard and No. 2 Ramp Bentley cylinder heads. | 11th Oct 1934 | Box 133 \ 2 scan0078 | |
| Comparison of No. 2 Ramp and Standard cylinder heads, focusing on constructional details and detonation performance. | 11th Oct 1934 | Box 133 \ 2 scan0079 | |
| Comparison of engine performance using different spark plug positions, cylinder heads (No.2 Ramp vs standard Bentley), and exhaust timing durations. | 11th Oct 1934 | Box 133 \ 2 scan0080 | |
| Effects of dual ignition, larger inlet valves, and indicated power on engine performance. | 11th Oct 1934 | Box 133 \ 2 scan0081 | |
| Report page detailing various valve timing comparisons in a table and discussing resulting mechanical troubles, specifically valve bounce. | 11th Oct 1934 | Box 133 \ 2 scan0082 | |
| Leaking exhaust valves in a standard Bentley head and future work on ramp and modified Bentley heads. | 26th May 1944 | Box 133 \ 2 scan0083 | |
| Graph showing the results of air consumption and volumetric efficiency tests on a Bentley single-cylinder engine. | 26th May 1944 | Box 133 \ 2 scan0084 | |
| Graph plotting Horse Power and Mean Effective Pressure against RPM for a single-cylinder Bentley engine test. | 5th Jan 1944 | Box 133 \ 2 scan0085 | |
| Graph plotting Brake Horse Power and B.M.E.P. against R.P.M. to show the effect of variation in exhaust duration on a Bentley single cylinder engine. | 5th Jan 1944 | Box 133 \ 2 scan0086 | |
| Graph showing power and consumption curves from Bentley single cylinder tests for the Nº2 Ramp Head. | 5th Jan 1944 | Box 133 \ 2 scan0087 | |
| Graph from the Bentley single cylinder tests showing the effect of dual ignition on power output, BMEP, and ignition advance against RPM. | 5th Jan 1944 | Box 133 \ 2 scan0088 | |
| Performance graph from a Bentley single-cylinder engine test showing power output with a large inlet valve (Nº 2 Ramp Head). | 5th Jan 1944 | Box 133 \ 2 scan0089 | |
| Graph plotting the effect of inlet valve orifice coefficient improvements on engine performance. | 5th Jan 1944 | Box 133 \ 2 scan0090 | |
| Graph plotting the effect of inlet valve orifice coefficient improvements on engine performance during Bentley single-cylinder tests. | 5th Jan 1944 | Box 133 \ 2 scan0091 | |
| Indicated power and consumption curves from Bentley single cylinder tests. | 5th Jan 1944 | Box 133 \ 2 scan0092 | |
| Graph comparing engine detonation performance between a No. 2 Ramp head and a standard Bentley head during single cylinder tests. | 5th Jan 1944 | Box 133 \ 2 scan0093 | |
| Graph showing the effect of spark plug position on detonation for a No.2 Ramp Head in a Bentley single-cylinder test engine. | 5th Jan 1944 | Box 133 \ 2 scan0094 | |
| Graph showing the effect of dual ignition on detonation for a Bentley single cylinder engine with a No. 2 Ramp Head. | 13th Nov 1934 | Box 133 \ 2 scan0095 | |
| Report on 'Ramp Head No.2', its promising performance, and suggestions for further modifications and testing. | 13th Nov 1934 | Box 133 \ 2 scan0096 | |
| Comparison of three valve head designs and a discussion on valve timing for competition cars. | 15th Nov 1934 | Box 133 \ 2 scan0097 | |
| Engine head design, focusing on turbulence, detonation, volumetric efficiency, and comparing single vs multi-cylinder performance. | 13th Nov 1934 | Box 133 \ 2 scan0098 | |
| Graph showing the volumetric efficiency and BMEP of Bentley Unit B.3 against engine RPM. | 12th Dec 1934 | Box 133 \ 2 scan0099 | |
| Power curve tests for a Standard Bentley Head with modified valve timing and no overlap. | 17th Nov 1934 | Box 133 \ 2 scan0100 | |
| Graph plotting Brake Horse Power against RPM to show the effect of valve timing overlap on a standard Bentley cylinder head. | 19th Nov 1934 | Box 133 \ 2 scan0101 | |
| Performance improvements and testing plans for a new Ramp No. 2 cylinder head design. | 19th Nov 1934 | Box 133 \ 2 scan0102 | |
| Report page discussing engine performance comparisons of the Ramp head, focusing on compression ratios and volumetric efficiency. | 19th Nov 1934 | Box 133 \ 2 scan0103 | |
| Car single cylinder development work, including cylinder heads, sleeve valves, and overhead camshafts. | 19th Nov 1934 | Box 133 \ 2 scan0104 | |
| Analysis of engine cylinder head designs, including overhead camshafts, four valves per cylinder, and hydraulic tappets. | 19th Nov 1934 | Box 133 \ 2 scan0105 | |
| Engine design considerations including supercharging, cylinder heads, and valve configurations. | 19th Nov 1934 | Box 133 \ 2 scan0106 | |
| Effect of stroke bore ratio on efficiency and challenges related to supercharging. | 19th Nov 1934 | Box 133 \ 2 scan0107 | |
| Chevrolet cylinder head improvement with staggered valves and suggesting further investigation. | 22th Nov 1934 | Box 133 \ 2 scan0108 | |
| Particulars and disadvantages of a Chevrolet cylinder head valve arrangement. | 27th Nov 1934 | Box 133 \ 2 scan0109 | |
| Improvements to cylinder head design, specifically regarding flame travel and breathing capacity. | 8th Dec 1934 | Box 133 \ 2 scan0110 | |
| No.2 Ramp Head Report and the effects of engine modifications on gas flow. | 8th Dec 1934 | Box 133 \ 2 scan0111 | |
| Comparing a Bentley 'Close-Centres' Head with a Standard Head. | 11th Dec 1934 | Box 133 \ 2 scan0112 | |
| Development work comparing a 'close-centres' cylinder head with a standard one on a single cylinder Bentley unit. | 11th Dec 1934 | Box 133 \ 2 scan0113 | |
| Detailed report and comparison of 'close-centres' and standard cylinder heads, discussing valve timing and constructional details. | 11th Dec 1934 | Box 133 \ 2 scan0114 | |
| Power output improvements from modifying engine valve and port sizes. | 1st Nov 1934 | Box 133 \ 2 scan0115 | |
| Analysis of the effect of reducing valve timing overlap on power for standard and 'close-centres' cylinder heads. | 1st Nov 1934 | Box 133 \ 2 scan0116 | |
| Analysis of engine power output, detonation, and valve timings at various RPM settings. | 1st Nov 1934 | Box 133 \ 2 scan0117 | |
| Tests and mechanical troubles with 'close-centres' heads, valve lift, and tappets. | 1st Nov 1934 | Box 133 \ 2 scan0118 | |
| Future work and recommendations for engine development, focusing on cylinder heads, carburettors, valves, and camshafts. | 1st Nov 1934 | Box 133 \ 2 scan0119 | |
| Graph comparing the performance of close-centres and standard cylinder heads on a single-cylinder test engine. | 1st Nov 1934 | Box 133 \ 2 scan0120 | |
| Graph charting the results of Bentley single-cylinder engine tests on the effect of improving the valve orifice coefficient. | 1st Nov 1934 | Box 133 \ 2 scan0121 | |
| Graph showing the effect of valve orifice coefficient improvements from Bentley single cylinder tests. | 1st Nov 1934 | Box 133 \ 2 scan0122 | |
| Graph showing the effect of valve timing overlap on the power of a standard Bentley single-cylinder head. | 1st Nov 1934 | Box 133 \ 2 scan0123 | |
| Graph showing the effect of valve timing overlap on power for a single cylinder engine test. | 1st Nov 1934 | Box 133 \ 2 scan0124 | |
| Blueprint graph showing power curves from a Bentley single-cylinder engine test with valves timed for 4000 RPM. | 1st Nov 1934 | Box 133 \ 2 scan0125 | |
| Graph comparing detonation, B.M.E.P., and ignition advance in Close-Centres vs. Standard Heads for Bentley Single Cylinder Tests. | 12th Dec 1934 | Box 133 \ 2 scan0126 | |
| Modifications for a small universal single cylinder unit, specifically a 9:1 compression ratio Bentley cylinder head. | 12th Dec 1934 | Box 133 \ 2 scan0127 | |
| Request for performance curves showing power variation with valve lift on a Small Universal Single Cylinder Unit, for development on the Wraith and Spectre models. | 12th Dec 1934 | Box 133 \ 2 scan0128 | |
| New design for a Bentley single cylinder head and ordering spare castings of the existing pattern. | 13th Dec 1934 | Box 133 \ 2 scan0129 | |
| Modifications to engine heads based on single-cylinder test results for competition work. | 13th Dec 1934 | Box 133 \ 2 scan0130 | |
| Proposing the creation of a second Bentley Universal Unit to prevent future design delays. | 1st Jan 1935 | Box 133 \ 2 scan0131 | |
| Outlining the priority of various engine research and modification jobs. | 19th Jan 1935 | Box 133 \ 2 scan0132 | |
| List of discussion topics regarding an exhaust-driven turbine, Kestrel and Exe engines, and alternative Car Heads. | 19th Jan 1935 | Box 133 \ 2 scan0133 | |
| Expressing concern about the de-prioritization and lack of progress on car single-cylinder unit work. | 21th Jan 1935 | Box 133 \ 2 scan0134 | |
| Viability of sleeve valve engines for use in motor cars, based on a conversation with Mr. Fedden. | 1st Feb 1935 | Box 133 \ 2 scan0135 | |
| Report comparing sleeve valve and poppet valve engine performance characteristics. | 1st Feb 1935 | Box 133 \ 2 scan0136 | |
| Comparative table of various engine specifications and performance data. | 27th Feb 1935 | Box 133 \ 2 scan0137 | |
| Comparison of power and detonation for high power heads using single and twin inlet valves. | 27th Feb 1935 | Box 133 \ 2 scan0138 | |
| Function and practicality of suction operated ignition control. | 8th Feb 1935 | Box 133 \ 2 scan0139 | |
| Graph showing the characteristics of the suction and speed-operated ignition control for a Graham-Paige car. | 9th Jan 1938 | Box 133 \ 2 scan0140 | |
| Graph of Bentley ignition advance curves at 2000 RPM, plotting brake lift against ignition advance for various loads. | 7th Jan 1935 | Box 133 \ 2 scan0141 | |
| Graph showing the volume distribution against flame travel for Bentley Standard and Ramp cylinder heads. | 8th Apr 1935 | Box 133 \ 2 scan0142 | |
| Requesting indicator cards for the Spectre engine to study combustion chamber characteristics. | 8th Apr 1935 | Box 133 \ 2 scan0143 | |
| Requesting indicator cards to be taken from a single cylinder unit. | 15th Apr 1935 | Box 133 \ 2 scan0144 | |
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