| Description | Date | Identifier | |
| Secret memo regarding a blueprint for SS valve springs and associated testing. | 23th Apr 1929 | Box 56 \ 2 Scan051 | |
| Valve lift curves and associated cam and rocker arm design. | 9th May 1928 | Box 56 \ 2 Scan052 | |
| Valve springs for Phantom engines, noting a clicking noise issue with double springs. | 11th May 1928 | Box 56 \ 2 Scan053 | |
| Analysis of Phantom double valve springs, comparing loads and bounce speeds to a standard single spring. | 11th May 1928 | Box 56 \ 2 Scan054 | |
| Investigation into a high-pitched clicking noise from the valve gear at a specific engine speed. | 8th Nov 1928 | Box 56 \ 2 Scan055 | |
| Suggestion from Elliott to Hives to increase the coil clearance on SS valve springs by altering the bottom washer. | 8th Nov 1928 | Box 56 \ 2 Scan056 | |
| New taper valve springs and camshaft provisions for the 20 HP engine to increase top speed. | 10th Nov 1928 | Box 56 \ 2 Scan057 | |
| Experimental 'SS' double valve springs and a proposal to use standard Phantom springs instead. | 13th Nov 1928 | Box 56 \ 2 Scan058 | |
| Paper on the design and failure analysis of valve springs. | 1st Jan 1929 | Box 56 \ 2 Scan059 | |
| Analysis of valve spring materials, heat treatment, and design to eliminate resonant vibrations, including comparative data and frequency formulas. | 1st Jan 1929 | Box 56 \ 2 Scan060 | |
| Page describing new industrial processes for cadmium plating and wire annealing, with a partial article on spring stress calculations. | 1st Jan 1929 | Box 56 \ 2 Scan061 | |
| On valve-spring design, discussing natural frequency, surge, stresses, and the effects of the number of coils. | 1st Jan 1929 | Box 56 \ 2 Scan062 | |
| Technical discussion on valve-spring stress, surge, and the factors leading to fatigue failure. | 1st Jan 1929 | Box 56 \ 2 Scan063 | |
| Investigation into valve spring performance, comparing double, single, and taper springs to address issues like bouncing and surging. | 20th Feb 1929 | Box 56 \ 2 Scan064 | |
| Comparative analysis of various valve springs, detailing their periodicity, performance, and application. | 20th Feb 1929 | Box 56 \ 2 Scan065 | |
| Analysis of spring periodicity and mean radius, comparing single, double, and Curtiss D.12 valve springs. | 20th Feb 1929 | Box 56 \ 2 Scan066 | |
| The speed at which resonance occurs in a spring system due to camshaft vibration. | 20th Feb 1929 | Box 56 \ 2 Scan067 | |
| Analysis of resonance and vibrations per revolution for inlet and exhaust cams. | 20th Feb 1929 | Box 56 \ 2 Scan068 | |
| Analysis of valve spring resonance, coil surging, and the properties of taper springs, including the Ricardo formula for natural frequency. | 20th Feb 1929 | Box 56 \ 2 Scan069 | |
| Conclusion document outlining six key points regarding spring design and performance. | 23th Feb 1929 | Box 56 \ 2 Scan070 | |
| Mr. Elliott's investigation into different types of valve springs. | 23th Feb 1929 | Box 56 \ 2 Scan071 | |
| Performance and potential redesign of the 'SS' Taper Valve Spring. | 14th Mar 1929 | Box 56 \ 2 Scan072 | |
| Technical memo on valve spring improvements for 20 HP and Aero engines, highlighting the advantages of taper springs. | 18th Mar 1929 | Box 56 \ 2 Scan073 | |
| Agreement to test a well-tapered valve spring against a parallel one. | 25th Mar 1929 | Box 56 \ 2 Scan074 | |
| Note regarding an extra heavy valve spring. | 2nd May 1929 | Box 56 \ 2 Scan075 | |
| Letter from Rolls-Royce of America to the UK discussing valve spring surge, referencing external papers, and requesting harmonic analysis of a cam layout. | 2nd May 1929 | Box 56 \ 2 Scan076 | |
| Valve spring design, harmonics, surging, and performance comparisons. | 2nd May 1929 | Box 56 \ 2 Scan077 | |
| Letter requesting notes or ideas regarding noise from springs and the tilt of faces. | 15th Jan 1929 | Box 56 \ 2 Scan078 | |
| Society of Automotive Engineers preprint paper on the idiosyncrasies and causes of issues with valve mechanisms. | 15th Jan 1929 | Box 56 \ 2 Scan079 | |
| Different instruments for studying valve-mechanism idiosyncrasies and valve motion. | 15th Jan 1929 | Box 56 \ 2 Scan080 | |
| Study of valve-mechanism idiosyncrasies, focusing on spring vibration, surge, and methods of measurement. | 15th Jan 1929 | Box 56 \ 2 Scan081 | |
| Analysis of valve-mechanism idiosyncrasies, detailing harmonic theory, valve lift curves, and spring vibrations. | 15th Jan 1929 | Box 56 \ 2 Scan082 | |
| Study of valve-mechanism idiosyncrasies, focusing on spring vibration and surge with experimental data graphs. | 15th Jan 1929 | Box 56 \ 2 Scan083 | |
| Technical paper on the idiosyncrasies and harmonic analysis of valve mechanisms. | 15th Jan 1929 | Box 56 \ 2 Scan084 | |
| Paper about using an electric telemeter to investigate valve-spring surge. | 15th Jan 1929 | Box 56 \ 2 Scan085 | |
| Paper on the use of an electric telemeter to measure and analyze valve-spring surge. | 15th Jan 1929 | Box 56 \ 2 Scan086 | |
| Mathematical and oscillogram analysis of valve-spring surge and harmonics. | 15th Jan 1929 | Box 56 \ 2 Scan087 | |
| Analysis of spring and cam harmonic characteristics with oscillograms and computed amplitude data. | 15th Jan 1929 | Box 56 \ 2 Scan088 | |
| Analysis of valve-spring surge using an electric telemeter, with spring characteristic data and oscillograms. | 15th Jan 1929 | Box 56 \ 2 Scan089 | |
| Analysis of valve-spring surge and stress using an electric telemeter to inform spring design. | 1st May 1929 | Box 56 \ 2 Scan090 | |
| Development of valve springs to reduce noise in the Phantom engine valve gear. | 1st May 1929 | Box 56 \ 2 Scan091 | |
| Continued discussion on engine valve train issues, including valve seating, tappet clearance, and valve spring performance. | 19th Mar 1930 | Box 56 \ 2 Scan092 | |
| Requesting the exact specifications for new valve springs for a high-speed test on development engine No. 20. | 19th Mar 1930 | Box 56 \ 2 Scan093 | |
| Valve spring coil vibrations and requesting specific data for a modified spring design. | 30th Aug 1930 | Box 56 \ 2 Scan094 | |
| Notes concerning the design of valve springs as affected by spring coil vibrations. | 28th Aug 1930 | Box 56 \ 2 Scan095 | |
| Technical analysis of the frequency of vibration in spiral springs, specifically in relation to valve spring breakages. | 28th Aug 1930 | Box 56 \ 2 Scan096 | |
| Theoretical analysis of spring design, discussing the relationship between frequency, stress, deflection, and material properties. | 28th Aug 1930 | Box 56 \ 2 Scan097 | |
| Analysis of stress, load, and deflection in parallel spiral springs using mathematical formulas. | 28th Aug 1930 | Box 56 \ 2 Scan098 | |
| Theoretical analysis of spring stresses, frequency, and deflection, including mathematical formulas. | 28th Aug 1930 | Box 56 \ 2 Scan099 | |
| The mathematical principles and properties of taper spiral springs. | 3rd Sep 1930 | Box 56 \ 2 Scan100 | |
| Attached notes on the subject of valve spring coil vibrations. | 3rd Sep 1930 | Box 56 \ 2 Scan101 | |
| Noise issues with the valve springs on the 20/25HP engine and proposing a solution. | 19th Sep 1930 | Box 56 \ 2 Scan102 | |
| Comparing the quietness and performance of two different valve springs, E.78071 and E.70442. | 25th Sep 1930 | Box 56 \ 2 Scan103 | |
| Modifications to valve springs and washers for the Phantom II and 20/25 HP chassis. | 29th Sep 1930 | Box 56 \ 2 Scan104 | |
| Blueprint detailing the location and part numbers of valve springs for the 20/25 HP and 40/50 HP chassis. | 27th Sep 1930 | Box 56 \ 2 Scan105 | |
| Quarterly complaint note regarding valve springs, suggesting they be changed in-house to avoid future issues. | 12th Nov 1930 | Box 56 \ 2 Scan106 | |
| Investigation into valve noise on a Phantom II, traced to improperly squared valve springs. | 10th Nov 1930 | Box 56 \ 2 Scan107 | |
| Improved spring and an issue with a filter fouling a cross member. | 13th Nov 1930 | Box 56 \ 2 Scan108 | |
| Extract from quarterly complaints regarding the fitting of a new spring and a disagreement on coil bedding. | 13th Nov 1930 | Box 56 \ 2 Scan109 | |
| Handing over new closed-end valve springs for the 20/25 HP and Phantom II models to the Experimental Department for testing due to noise issues. | 22th Nov 1930 | Box 56 \ 2 Scan110 | |
| The mathematical formulas for calculating valve spring wave velocity. | 22th Nov 1930 | Box 56 \ 2 Scan111 | |
| The formulas for wave velocity and stress in terms of load. | 18th Dec 1931 | Box 56 \ 2 Scan112 | |
| Page of valve spring calculations for a 40/50 model. | 18th Dec 1931 | Box 56 \ 2 Scan113 | |
| Requesting a further set of 25 HP valve springs with revised specifications to achieve the required load. | 19th Jan 1932 | Box 56 \ 2 Scan114 | |
| Technical memorandum detailing empirical data and requirements for Phantom II and 25 HP valve springs. | 21th Jan 1932 | Box 56 \ 2 Scan115 | |
| Standardisation of valve springs, bottom washers, and valve guides to enable higher engine revs without spring bounce. | 7th Jan 1932 | Box 56 \ 2 Scan116 | |
| Standardisation form for a chassis part change. | 2nd Jan 1932 | Box 56 \ 2 Scan117 | |
| Rating test results for Peregrine Tappet and Valve springs, showing deflection under various loads. | 24th May 1932 | Box 56 \ 2 Scan118 | |
| Graphs showing load vs. deflection spring ratings for 'Peregrine' Tappet and Valve springs. | 24th May 1932 | Box 56 \ 2 Scan119 | |
| Testing double valve springs and requesting a set be fitted to an engine. | 8th Aug 1932 | Box 56 \ 2 Scan120 | |
| Request to run an endurance test on valve springs using a test bed unit. | 6th Aug 1932 | Box 56 \ 2 Scan121 | |
| Exhaust valve failure on a Phantom II Unit 25 engine, with detailed specifications for valve springs. | 27th May 1932 | Box 56 \ 2 Scan122 | |
| Requesting the fitting of a set of double valve springs to a high compression head for P.2 25. | 23th Sep 1932 | Box 56 \ 2 Scan123 | |
| Carburetter modifications and performance improvements for the 20 HP car, comparing it to competitors. | 1st Sep 1925 | Box 56 \ 2 Scan124 | |
| Solutions for a broken Goshawk engine induction pipe flange and future design considerations. | 14th Sep 1925 | Box 56 \ 2 Scan125 | |
| Attempts to increase power on a 20 HP engine and related chassis weight increases. | 1st Feb 1926 | Box 56 \ 2 Scan126 | |
| Experiments to determine if the power output of the 20 HP engine could be increased by using a larger carburetter. | 2nd Feb 1926 | Box 56 \ 2 Scan127 | |
| Engine power test results comparing standard and large carburetter throttles, and the effect of throat size on power output. | 15th Jan 1925 | Box 56 \ 2 Scan128 | |
| Carburetter metering issues and maximum power tests on a 20 HP engine. | 15th Jan 1925 | Box 56 \ 2 Scan129 | |
| Test report comparing the performance of a standard carburetter against a diffuser jet carburettor, including a performance graph. | 15th Jan 1925 | Box 56 \ 2 Scan130 | |
| Report page summarising experiments on carburettors, including a diffuser model and one with a light air valve. | 15th Jan 1925 | Box 56 \ 2 Scan131 | |
| Experiments into carburetter throat size and diffuser jets as a solution to power loss in the 20 HP engine. | 1st Mar 1926 | Box 56 \ 2 Scan132 | |
| Modifications to the 20 HP induction and exhaust pipes with a strengthened flange. | 1st Mar 1926 | Box 56 \ 2 Scan133 | |
| Approving the design for a 20 HP engine's aluminium induction pipe. | 24th Mar 1926 | Box 56 \ 2 Scan134 | |
| The instruction to proceed with work on 20 HP induction and exhaust pipes. | 25th Mar 1926 | Box 56 \ 2 Scan135 | |
| Comparison between a Lorraine car and a 20 HP model using different carburetters and chassis. | 9th Nov 1926 | Box 56 \ 2 Scan136 | |
| The new 20 HP induction system, detailing its advantages over the standard system, including weight reduction and simplified manufacturing. | 27th Jan 1927 | Box 56 \ 2 Scan137 | |
| Test report comparing the performance of 'Manifolds to LeC. 2216' against standard manifolds, with power curve data. | 21th Mar 1928 | Box 56 \ 2 Scan138 | |
| Design schemes and modifications for the India 3 engine. | 21th Mar 1928 | Box 56 \ 2 Scan139 | |
| Recurring failure of induction pipes on the 20 HP exhaust and induction system, requesting a standardization sheet for an improved design. | 1st Apr 1927 | Box 56 \ 2 Scan140 | |
| With a diagram discussing an alternative design for an induction pipe to prevent fuel flow issues. | 7th Apr 1928 | Box 56 \ 2 Scan141 | |
| Technical letter discussing carburetter design with accompanying hand-drawn diagrams. | 5th Apr 1927 | Box 56 \ 2 Scan142 | |
| Standardisation report for replacing the cast iron induction pipe with an aluminium one to improve reliability. | 5th Apr 1927 | Box 56 \ 2 Scan143 | |
| Costs and implementation details for a new part on the 'L' series chassis. | 8th Oct 1927 | Box 56 \ 2 Scan144 | |
| Potential engine design improvements and modifications. | 2nd Feb 1928 | Box 56 \ 2 Scan145 | |
| Potential modifications to the cylinder head and induction pipe arrangement for the India 3 model. | 1st Apr 1928 | Box 56 \ 2 Scan146 | |
| Arrangement of the cylinder head and induction pipe for 'INDIA 3', enclosing drawing LeC.2541. | 4th May 1928 | Box 56 \ 2 Scan147 | |
| Blueprint for an underfed type of induction pipe, detailing a modification to lower the carburettor. | 5th Apr 1928 | Box 56 \ 2 Scan148 | |
| Design of induction pipes and carburettors for the 'India 3' project, making comparisons to the 'SS' Phantom model. | 8th Apr 1928 | Box 56 \ 2 Scan149 | |
| Novel, patentable scheme for car induction pipe heating using an exhaust hot spot and a valve. | 21th Jun 1928 | Box 56 \ 2 Scan150 | |
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