| Description | Date | Identifier | |
| Graph plotting B.M.E.P. and B.HP against R.P.M. for a high-power head, multi-cylinder engine. | 7th Feb 1930 | Box 182 \ M19 img282 | |
| Performance graph comparing B.M.E.P. and B.HP for single and 6-cylinder engines. | 7th Feb 1930 | Box 182 \ M19 img283 | |
| Graph showing Phantom II power curves with open exhaust for three different shaft configurations. | 7th Jul 1931 | Box 182 \ M19 img284 | |
| Performance graph showing BHP and MEP against RPM, with corresponding valve timing diagrams for three different camshafts. | 7th Jul 1931 | Box 182 \ M19 img285 | |
| Table detailing 16 steering tests conducted using a snatchmeter for recording vehicle performance under various conditions. | 7th Jul 1931 | Box 182 \ M19 img286 | |
| Steering tests using a snatchmeter to record joggling under various car conditions. | 7th Jul 1931 | Box 182 \ M19 img287 | |
| Graph from cooling tests showing air temperature rise against road speed, comparing results with the bonnet on and off using hexagonal matrix tubes. | 23th Sep 1931 | Box 182 \ M19 img288 | |
| Graph plotting air temperature increase against road speed for tests on a radiator and air flow to the floorboards. | 23th Sep 1931 | Box 182 \ M19 img289 | |
| Blueprint graph of 25EX cooling tests comparing air temperature rise with the vehicle's bonnet on and off. | 23th Sep 1931 | Box 182 \ M19 img290 | |
| Graph showing air temperature rise across the radiator and to the floorboards at various road speeds. | 23th Sep 1931 | Box 182 \ M19 img291 | |
| Performance graph comparing 1 3/4' and 1 1/4' chokes for a P.I. Unit B.J. 55 for 27 EX engine. | 23th Sep 1931 | Box 182 \ M19 img292 | |
| Blueprint performance graph showing engine power curves and a valve timing diagram. | 5th Oct 1931 | Box 182 \ M19 img293 | |
| Performance test results for a 27 Ex. car at Brooklands, including acceleration data and lap speeds. | 5th Oct 1931 | Box 182 \ M19 img294 | |
| American battery ignition systems, current draw, and component materials. | 4th Mar 1924 | Box 182 \ M20 \ M20.1 img001 | |
| Diagram and description of a combined magneto and battery ignition automatic advance mechanism using a hydraulic relay. | 1st Apr 1924 | Box 182 \ M20 \ M20.1 img002 | |
| Descriptive page with diagrams explaining a 5-piston valve arrangement and its operation. | 1st Apr 1924 | Box 182 \ M20 \ M20.1 img003 | |
| Technical memorandum discussing ignition advance mechanisms and engine component modifications. | 1st Apr 1924 | Box 182 \ M20 \ M20.1 img004 | |
| Failure of a worm tube and steering lever bolts during a 40/50 front brake bump test. | 1st Apr 1924 | Box 182 \ M20 \ M20.1 img005 | |
| Secret memorandum discussing servo lag and sticking issues, with proposed solutions and comparisons to other systems. | 7th Apr 1924 | Box 182 \ M20 \ M20.1 img006 | |
| Design of front axle controls, spring adjustments, and the future composition of the design committee. | 4th Oct 1924 | Box 182 \ M20 \ M20.1 img007 | |
| Design of brake operating gear, specifically pin size, friction materials, and performance compared to Hispano. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img008 | |
| Need for more ignition advance, considering spark timing, plug positioning, and combustion chamber shape. | 10th Apr 1924 | Box 182 \ M20 \ M20.1 img009 | |
| Steering geometry and methods to mitigate road shocks. | 1st Apr 1924 | Box 182 \ M20 \ M20.1 img010 | |
| Critical review of a servo design, with detailed suggestions for modification and improvement. | 11th Apr 1924 | Box 182 \ M20 \ M20.1 img011 | |
| Technical memo with diagrams discussing the design of connecting rods and lifting pins. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img012 | |
| Design and improvement of a servo mechanism with sketches. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img013 | |
| Annotated diagrams and design notes for a mechanical pressure unit. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img014 | |
| Secret memo discussing design calculations, problems, and theories related to four-wheel brake systems and servo assistance. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img015 | |
| Continuation of a report discussing design considerations and drawbacks of different servo mechanisms. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img016 | |
| Design improvements and considerations for a servo mechanism, including diagrams. | 4th Apr 1924 | Box 182 \ M20 \ M20.1 img017 | |
| Technical note with diagrams and annotations regarding the design of mechanical rods and levers. | 16th Apr 1924 | Box 182 \ M20 \ M20.1 img018 | |
| Steering geometry challenges, wheel obstructions, and the effects of different tyre and suspension setups. | 16th Apr 1924 | Box 182 \ M20 \ M20.1 img019 | |
| Technical memo discussing a single ratchet servo braking scheme, its characteristics, and modifications. | 25th Apr 1924 | Box 182 \ M20 \ M20.1 img020 | |
| Performance issues like vibration and detonation in the E.A.C. engine, and proposing improvements. | 5th Jan 1924 | Box 182 \ M20 \ M20.1 img021 | |
| Secret memo containing a copy of Mr. Royce's notes on servo design, braking, and upcoming car availability at Wittering. | 1st May 1924 | Box 182 \ M20 \ M20.1 img022 | |
| Brake servo design, issues with binding, and proposals for improvements and testing. | 1st May 1924 | Box 182 \ M20 \ M20.1 img023 | |
| Secret memo discussing the design requirements for a servo braking system, weighing different operational theories and component choices. | 13th May 1924 | Box 182 \ M20 \ M20.1 img024 | |
| Merits of different braking servo schemes and the potential adoption of a 4-wheel system. | 1st May 1924 | Box 182 \ M20 \ M20.1 img025 | |
| Modifications to the servo system, including alterations to the servo plates and connecting rods. | 3rd May 1924 | Box 182 \ M20 \ M20.1 img026 | |
| Secret memo discussing experiments to avoid 'jaggers' by testing stiff versus flexible brake drums. | 3rd May 1924 | Box 182 \ M20 \ M20.1 img027 | |
| Merits of a disc crankshaft and its potential to reduce flywheel weight in aero engines. | 8th May 1924 | Box 182 \ M20 \ M20.1 img028 | |
| Production pedal foot plate designed to reduce hot air in the cabin, and preferring steel over brass screws for its assembly. | 1st May 1924 | Box 182 \ M20 \ M20.1 img029 | |
| Comparing a newly adopted braking scheme against other options, including the Hispano system. | 19th May 1924 | Box 182 \ M20 \ M20.1 img030 | |
| Test report on brake performance, a comparison with a Hispano car, and details on clutch, carburettor, and exhaust system issues and modifications. | 1st May 1924 | Box 182 \ M20 \ M20.1 img031 | |
| Clutch not stopping due to gravity and a new design for a gravity clutch brake. | 1st May 1924 | Box 182 \ M20 \ M20.1 img032 | |
| Drawing No. LeC. 1869 for a spring pressure device related to the clutch brake. | 12th May 1924 | Box 182 \ M20 \ M20.1 img033 | |
| Secret memorandum discussing fitting a braking system and proposing to replace the 3-speed gearbox with a new 4-speed unit. | 13th May 1924 | Box 182 \ M20 \ M20.1 img034 | |
| Improvements to the front axle, steering control, and chassis design for safety. | 17th May 1924 | Box 182 \ M20 \ M20.1 img035 | |
| Modifications to the frame width and an increase to the rear wheel track. | 20th May 1924 | Box 182 \ M20 \ M20.1 img036 | |
| Secret memo requesting experiments to measure spring deflection and determine maximum pivot inclination for front wheel braking systems. | 20th May 1924 | Box 182 \ M20 \ M20.1 img037 | |
| Secret memo from DA to HS regarding an upcoming trip to Derby to investigate steering and braking problems. | 21th May 1924 | Box 182 \ M20 \ M20.1 img038 | |
| On the decision to use a governed Scintilla magneto and a specific switchbox design for the EAC.2 engine. | 24th May 1924 | Box 182 \ M20 \ M20.1 img039 | |
| Brake design principles, skid characteristics, and materials for brake drums. | 11th Aug 1920 | Box 182 \ M20 \ M20.1 img040 | |
| Secret memo detailing defects and proposed modifications for a steering servo adjustment mechanism. | 5th May 1924 | Box 182 \ M20 \ M20.1 img041 | |
| Design changes for front axle control, specifically regarding the adoption of radius rods over torque arms with semi-elliptic springs. | 1st May 1924 | Box 182 \ M20 \ M20.1 img042 | |
| Experimental testing of front axle control systems, focusing on spring and rod arrangements. | 29th May 1924 | Box 182 \ M20 \ M20.1 img043 | |
| Letter from F. H. Royce to A. W. Claremont detailing patentable schemes for a 4-wheel brake system. | 3rd Jun 1924 | Box 182 \ M20 \ M20.1 img044 | |
| R to E giving opinions on wire wheels, bevel pinions, gear levers, and the 20.HP. foot brake. | 3rd Jun 1924 | Box 182 \ M20 \ M20.1 img045 | |
| Staff holidays, a request to borrow a car for a trip to London, and a proposal to test semi-balloon tyres. | 3rd Jun 1924 | Box 182 \ M20 \ M20.1 img046 | |
| Car with an adopted braking scheme, covering pedal pressure, servo, safety, steering, and clutch performance. | 1st Jun 1924 | Box 182 \ M20 \ M20.1 img047 | |
| Modifications to front brake drums, servo drive noise, and general brake system performance. | 23th Jun 1924 | Box 182 \ M20 \ M20.1 img048 | |
| Patentability of a plate clutch for a servo system in comparison to Renault and Hispano designs. | 23th Jun 1924 | Box 182 \ M20 \ M20.1 img049 | |
| Letter from F. H. Royce confirming an agreement to test an experimental engine for a Mr. Micklewood. | 24th Jun 1924 | Box 182 \ M20 \ M20.1 img050 | |
| Review and set of decisions on American standardisation sheets numbered 31 to 39. | 26th Jun 1924 | Box 182 \ M20 \ M20.1 img051 | |
| Scheme for adapting double radius rods to the front axle control, requesting testing by the Experimental Department. | 26th Jun 1924 | Box 182 \ M20 \ M20.1 img052 | |
| Noise complaint in the servo drive, comparing a 7 to 1 reduction with a 10 to 1 reduction. | 27th Jun 1924 | Box 182 \ M20 \ M20.1 img053 | |
| Secret memo discussing design changes to the petrol tank and fittings for cars with 4-wheel brakes, including the adoption of a vacuum system. | 27th Jun 1924 | Box 182 \ M20 \ M20.1 img054 | |
| From R. to H.S. regarding the successful development of quiet gears for the servo drive. | 30th Jun 1924 | Box 182 \ M20 \ M20.1 img055 | |
| To determine the required degree of ignition advance on an EAC engine. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img001 | |
| Ignition advance required to maintain power for the E.A.C. engine. | 19th Jul 1923 | Box 182 \ M20 \ M20.2 img002 | |
| Engine performance with synchronized ignitions and magneto-only ignition. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img003 | |
| Showing a data table for 'Both Ignitions' performance. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img004 | |
| Graph of ignition curves for an EAC engine, with Hispano curves for comparison. | 31th Mar 1929 | Box 182 \ M20 \ M20.2 img005 | |
| Graph of ignition curves showing the minimum advance required to maintain output for an E.A.C. engine. | 31th Mar 1924 | Box 182 \ M20 \ M20.2 img006 | |
| Bump test for the 40/50 chassis, detailing the performance and failures of front springs and the frame. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img007 | |
| List of important component failures with running times and remarks, excluding the frame and springs. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img008 | |
| Log of frame failures detailing the location and type of crack, with accompanying illustrative sketches. | 4th Apr 1924 | Box 182 \ M20 \ M20.2 img009 | |
| The 20 HP radiator and shutters. | 4th Apr 1924 | Box 182 \ M20 \ M20.2 img010 | |
| Water boiling issues in the 20 HP model and a recommendation for a new radiator with thermostat-operated shutters. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img011 | |
| Secret memorandum discussing E.A.C. engine mounting, crankcase design, and retard vibration issues. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img012 | |
| Tests conducted on a modified exhaust system for the EAC 111. | 5th Apr 1924 | Box 182 \ M20 \ M20.2 img013 | |
| Tests with two cars in France, detailing issues with steering, wheels, and brakes. | 1st Apr 1924 | Box 182 \ M20 \ M20.2 img014 | |
| Worsening complaint of 'jaggers' (judder) on front brakes and a proposed change to the brake balance. | 4th Apr 1924 | Box 182 \ M20 \ M20.2 img015 | |
| Comparative steering tests for the 40/50 model, focusing on pivot lean and centre-point steering. | 4th Apr 1924 | Box 182 \ M20 \ M20.2 img016 | |
| Steering wind-up, front brake tests, and issues with pivot pin bushes. | 11th Apr 1924 | Box 182 \ M20 \ M20.2 img017 | |
| The losses in a flat disc type servo. | 14th Apr 1924 | Box 182 \ M20 \ M20.2 img018 | |
| Car tests in France, detailing front axle modifications and component issues. | 16th Apr 1924 | Box 182 \ M20 \ M20.2 img019 | |
| Secret memo regarding tests conducted on a slow-speed servo. | 17th Apr 1924 | Box 182 \ M20 \ M20.2 img020 | |
| Tests conducted on an improved slow-speed servo. | 17th Apr 1924 | Box 182 \ M20 \ M20.2 img021 | |
| Car braking system test, noting performance on wet and greasy roads. | 23th Apr 1924 | Box 182 \ M20 \ M20.2 img022 | |
| 4-wheel brakes, detailing adjustments to a servo system. | 28th Apr 1924 | Box 182 \ M20 \ M20.2 img023 | |
| The performance of different vehicle braking schemes and servo assistance. | 28th Apr 1924 | Box 182 \ M20 \ M20.2 img024 | |
| The operation and feel of the brake pedal and servo mechanism. | 28th Apr 1924 | Box 182 \ M20 \ M20.2 img025 | |
| Comparing an improved 'agreed' brake servo scheme with the Hispano system. | 28th Apr 1924 | Box 182 \ M20 \ M20.2 img026 | |
| The M.DES.60 braking scheme, detailing faults, modifications, and comparisons. | 28th Apr 1924 | Box 182 \ M20 \ M20.2 img027 | |
| Secret report on the braking inefficiency and weakness of a rebuilt Hispano servo motor. | 29th Apr 1924 | Box 182 \ M20 \ M20.2 img028 | |
| The RRM braking scheme, noting issues with brake jaggers and the action of the servo. | 1st May 1924 | Box 182 \ M20 \ M20.2 img029 | |
| Comparing the lag and pedal feel of different brake servo schemes, specifically the RRM and Hispano. | 20th Sep 1924 | Box 182 \ M20 \ M20.2 img030 | |
| Report outlining experiments conducted to eliminate a braking issue referred to as 'jaggers'. | 1st May 1924 | Box 182 \ M20 \ M20.2 img031 | |
| Secret memo proposing a visit to test different 4-wheel brake systems on Hispano and EAC cars. | 1st May 1924 | Box 182 \ M20 \ M20.2 img032 | |
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