| Description | Date | Identifier | |
| Confirming authority to proceed with manufacturing split pistons and converting existing castings. | 22th Nov 1919 | Box 77 \ 3 scan0031 | |
| Typed copy of a telegram from Royce regarding piston design, engine testing and logistics for the 1 EX chassis. | 22th Nov 1919 | Box 77 \ 3 scan0032 | |
| Covering note for the X.3732 Split Piston Standardisation Sheet. | 26th Nov 1919 | Box 77 \ 3 scan0033 | |
| Recommendation regarding the turning of a band of metal on split type pistons. | 28th Nov 1919 | Box 77 \ 3 scan0034 | |
| Request for a car with split type pistons for experimentation at West Wittering. | 29th Nov 1919 | Box 77 \ 3 scan0035 | |
| Fitting of split type pistons to the 1.EX car and its scheduled journey. | 1st Dec 1919 | Box 77 \ 3 scan0036 | |
| Potential improvements to the design of split-type pistons. | 1st Dec 1919 | Box 77 \ 3 scan0037 | |
| Over-oiling issues with Car 1.EX and subsequent modifications to the pistons, clutch, wiring, and thermometer. | 3rd Dec 1919 | Box 77 \ 3 scan0038 | |
| From EH to R detailing modifications and issues with car 1.EX, including over-oiling and other updates. | 3rd Dec 1919 | Box 77 \ 3 scan0039 | |
| Agreeing to a proposal to modify split type pistons. | 1st Dec 1919 | Box 77 \ 3 scan0040 | |
| The machining of existing piston castings for a split piston arrangement. | 1st Dec 1919 | Box 77 \ 3 scan0041 | |
| Cover letter for a standardisation sheet regarding split type pistons. | 10th Dec 1919 | Box 77 \ 3 scan0042 | |
| Standardisation document for a split, oval ground piston designed to eliminate piston knocks. | 22th Nov 1919 | Box 77 \ 3 scan0043 | |
| Table of compression and permanent set measurements for a split type piston under varying weights. | 22th Nov 1919 | Box 77 \ 3 scan0044 | |
| Tests on standard and split pistons to show deflection with various loads. | 9th Apr 1919 | Box 77 \ 3 scan0045 | |
| Instructions sheet detailing test data for Standard Pistons under various loads measured in LBS. | 9th Apr 1919 | Box 77 \ 3 scan0046 | |
| Standardisation of split pistons, production limitations due to a strike, and an investigation into an 'illusive' engine knock. | 12th Dec 1919 | Box 77 \ 3 scan0047 | |
| Test report on the performance of split type pistons, noting some knocking issues. | 18th Nov 1919 | Box 77 \ 3 scan0048 | |
| Faults, such as increasing clearances, found in split-type pistons and potential design improvements. | 12th Dec 1919 | Box 77 \ 3 scan0049 | |
| Overcoming piston knocks, considering split pistons and the potential use of cast iron over aluminium due to production issues. | 12th Dec 1919 | Box 77 \ 3 scan0050 | |
| The pros and cons of cast iron versus aluminium pistons, considering seizure risk, weight, and engine silence. | 12th Dec 1919 | Box 77 \ 3 scan0051 | |
| The reliability of aluminium pistons versus cast iron pistons, citing issues at other car companies. | 12th Dec 1919 | Box 77 \ 3 scan0052 | |
| Testing letter box slot and Zephyr type pistons, detailing issues with clearances, seizing, and knocking. | 16th Dec 1919 | Box 77 \ 3 scan0053 | |
| Continued memo fragment describing pushing components into a cylinder bore. | 16th Dec 1919 | Box 77 \ 3 scan0054 | |
| Piston design challenges, comparisons with Bentley pistons, and experiments with modifying them. | 29th Dec 1919 | Box 77 \ 3 scan0055 | |
| Piston experiments, discussing different types, issues like seizure and knocking, and future testing plans. | 29th Dec 1919 | Box 77 \ 3 scan0056 | |
| Recommendation to adopt an improved split aluminium piston design, drawing N. 2820. | 17th Jan 1920 | Box 77 \ 3 scan0057 | |
| Change from aluminium to cast iron pistons and their performance. | 17th Jan 1920 | Box 77 \ 3 scan0058 | |
| Modified design for an aluminium split piston. | 19th Jan 1920 | Box 77 \ 3 scan0059 | |
| Challenges and decisions surrounding the bulk production of pistons, including a newly redesigned split piston. | 6th Feb 1920 | Box 77 \ 3 scan0060 | |
| Gas leakage past split type pistons, detailing the resulting noise, inefficiency, and fumes entering the vehicle body. | 6th Feb 1920 | Box 77 \ 3 scan0061 | |
| Expressing dissatisfaction with dynamometer power and compression readings. | 22th Mar 1920 | Box 77 \ 3 scan0062 | |
| Extract from a Test Department report regarding piston rattles and the status of chassis with various piston types. | 22th Mar 1920 | Box 77 \ 3 scan0063 | |
| Cylinder bore wear caused by aluminium versus cast iron pistons. | 12th Apr 1920 | Box 77 \ 3 scan0064 | |
| Piston material, comparing cast iron to aluminium, and related issues like wear, seizure, and decarbonisation. | 12th Apr 1920 | Box 77 \ 3 scan0065 | |
| Piston troubles, including knock in aluminium pistons and a repair procedure, along with tests on new split cast iron pistons. | 12th Apr 1920 | Box 77 \ 3 scan0066 | |
| Piston testing, focusing on clearances, piston knock, and gas leakage. | 12th Apr 1920 | Box 77 \ 3 scan0067 | |
| Analysis of piston ring performance regarding gas sealing, oil control, and crankcase vapour. | 2nd Apr 1920 | Box 77 \ 3 scan0068 | |
| Comparison of horsepower for engines with cast iron versus aluminium pistons, and a test showing HP with different numbers of rings. | 12th Apr 1920 | Box 77 \ 3 scan0069 | |
| Inquiry from Walker M. Levett Company regarding the history of slotted pistons. | 26th Jul 1922 | Box 77 \ 3 scan0070 | |
| Proposed suggestions to cure over-oiling with the silent ram piston on the 40/50 HP chassis. | 24th Nov 1919 | Box 77 \ 3 scan0071 | |
| Potential piston and cylinder modifications, including baffle plates and a plunger design. | 24th Nov 1919 | Box 77 \ 3 scan0072 | |
| The specifications for three experimental silent ram pistons intended for the 40/50 HP chassis. | 27th Nov 1919 | Box 77 \ 3 scan0073 | |
| Modifications to an oil collecting groove and a C piston, and requesting materials for tests. | 27th Nov 1919 | Box 77 \ 3 scan0074 | |
| Testing Ram Type silent pistons, detailing issues with over-oiling and piston knock. | 9th Dec 1919 | Box 77 \ 3 scan0075 | |
| Urgent fitting of pistons for a car scheduled for a 10,000-mile run in France. | 9th Dec 1919 | Box 77 \ 3 scan0076 | |
| Providing a status update on five experiments related to pistons, starter gear, brake shaft, and speedometer drive. | 10th Jun 1920 | Box 77 \ 3 scan0077 | |
| Effectiveness and drawbacks of split aluminium pistons from the Aerolite Piston Co. | 1st Nov 1919 | Box 77 \ 3 scan0078 | |
| Testing standard 'letter box slot' pistons and special 'Zephyr' pistons, detailing issues with clearances and knocking. | 16th Dec 1919 | Box 77 \ 3 scan0079 | |
| Typed page fragment discussing the process of fitting components into a cylinder bore. | 16th Dec 1919 | Box 77 \ 3 scan0080 | |
| Piston designs, including the Zephyr split piston and potential improvements using steel springs. | 22th Dec 1919 | Box 77 \ 3 scan0081 | |
| Extract discussing the effectiveness of plunger rings and cast iron pistons. | 22th Dec 1919 | Box 77 \ 3 scan0082 | |
| List of new parts fitted to a car intended for a 10,000-mile run, with accompanying remarks. | 5th Jan 1920 | Box 77 \ 3 scan0083 | |
| Request for a complete set of the latest type of aluminium pistons for a 10,000-mile chassis test. | 7th Jan 1920 | Box 77 \ 3 scan0084 | |
| The conversion of condemned solid pistons to a split type by splitting and stretching. | 15th Jan 1920 | Box 77 \ 3 scan0085 | |
| Recommendation to adopt an improved design of split aluminium pistons, referencing drawing N. 2820. | 17th Jan 1920 | Box 77 \ 3 scan0086 | |
| Continued discussion on fitting cast iron pistons to specific cars and the expected performance differences compared to aluminium pistons. | 17th Jan 1920 | Box 77 \ 3 scan0087 | |
| Instruction memo reporting on the performance of experimental pistons, noting increased vibration in a demonstration car. | 19th Jan 1920 | Box 77 \ 3 scan0088 | |
| Modified type of split piston and its comparison to the current design. | 19th Jan 1920 | Box 77 \ 3 scan0089 | |
| Bulk production of pistons, material constraints, and a re-designed split piston. | 21th Jan 1920 | Box 77 \ 3 scan0090 | |
| The delayed standardization of a modified aluminium belt piston pending a 10,000-mile test run. | 27th Jan 1920 | Box 77 \ 3 scan0091 | |
| Unreliability of current pistons and the prospects of a modified aluminium split piston design. | 27th Jan 1920 | Box 77 \ 3 scan0092 | |
| Providing design specifications for a split aluminium piston for the 40/50 HP chassis. | 28th Jan 1920 | Box 77 \ 3 scan0093 | |
| Continuation of a discussion regarding proposed modifications to an aluminium piston design. | 28th Jan 1920 | Box 77 \ 3 scan0094 | |
| Letter discussing vehicle testing feedback, mileage targets, piston knock issues, and a comparison with another car. | 28th Jan 1920 | Box 77 \ 3 scan0095 | |
| Typed report on the performance and condition of a car chassis, detailing various mechanical observations and mileage. | 28th Jan 1920 | Box 77 \ 3 scan0096 | |
| Progress report on a 10,000-mile test of the latest type of split aluminium pistons. | 29th Jan 1920 | Box 77 \ 3 scan0097 | |
| Progress report on a 10,000-mile test of the latest type of split aluminium pistons. | 29th Jan 1920 | Box 77 \ 3 scan0098 | |
| Recommendation on the machining process for improved type OD split pistons. | 30th Jan 1920 | Box 77 \ 3 scan0099 | |
| The proposed modification to the piston slot width and updating the relevant drawings. | 30th Jan 1920 | Box 77 \ 3 scan0100 | |
| Interim report on the 10,000-mile test of latest type split aluminium pistons. | 30th Jan 1920 | Box 77 \ 3 scan0101 | |
| The 10,000-mile test of the latest type of split pistons, noting elusive engine knocks. | 31th Jan 1920 | Box 77 \ 3 scan0102 | |
| 10,000 miles test of split aluminium pistons, noting mileage and a piston knock issue. | 2nd Feb 1920 | Box 77 \ 3 scan0103 | |
| Test report on the latest type of split aluminium pistons for chassis 53-CW, noting mileage and an audible piston knock. | 4th Feb 1920 | Box 77 \ 3 scan0104 | |
| Progress report on a 10,000-mile test of the latest type of split aluminium pistons. | 4th Feb 1920 | Box 77 \ 3 scan0105 | |
| List of items and modifications to be fitted to a trials car chassis for America. | 4th Feb 1920 | Box 77 \ 3 scan0106 | |
| Test report on the performance of the latest type of split aluminium pistons. | 5th Feb 1920 | Box 77 \ 3 scan0107 | |
| The 10,000 miles test of latest type split aluminium pistons. | 6th Feb 1920 | Box 77 \ 3 scan0108 | |
| The 10,000-mile test of the latest type of split aluminium pistons, detailing engine knock issues. | 7th Feb 1920 | Box 77 \ 3 scan0109 | |
| The 10,000 miles test of the latest type of split aluminium pistons. | 9th Feb 1920 | Box 77 \ 3 scan0110 | |
| Providing a mileage update for the 10,000-mile test of the latest type of split aluminium pistons. | 10th Feb 1920 | Box 77 \ 3 scan0111 | |
| Daily log report from February 1920 detailing vehicle maintenance, repairs, and performance. | 11th Feb 1920 | Box 77 \ 3 scan0112 | |
| Daily log of vehicle performance, maintenance, and issues encountered during road tests. | 11th Feb 1920 | Box 77 \ 3 scan0113 | |
| Progress report on a 10,000-mile test of latest type split aluminium pistons, noting mileage and audible knocks. | 2nd Feb 1920 | Box 77 \ 3 scan0114 | |
| 10,000-mile test of the latest type of split aluminium pistons, detailing a persistent engine knocking issue. | 12th Feb 1920 | Box 77 \ 3 scan0115 | |
| 10,000-mile test of the latest type of split aluminium pistons. | 13th Feb 1920 | Box 77 \ 3 scan0116 | |
| Developed piston knock in chassis 1.TW and its subsequent repair. | 13th Feb 1920 | Box 77 \ 3 scan0117 | |
| Elusive engine knock during a 10,000-mile test of the latest type of split aluminium pistons. | 14th Feb 1920 | Box 77 \ 3 scan0118 | |
| 10,000-mile test of the latest type of split aluminium pistons, noting issues with elusive knocks. | 16th Feb 1920 | Box 77 \ 3 scan0119 | |
| The testing of the latest type of split aluminium pistons and the investigation of elusive knocks. | 18th Feb 1920 | Box 77 \ 3 scan0120 | |
| The mileage testing of improved split pistons and their effectiveness in overcoming piston knock. | 20th Feb 1920 | Box 77 \ 3 scan0121 | |
| Investigation into an elusive engine knock, potentially caused by piston or connecting rod side-play. | 20th Feb 1920 | Box 77 \ 3 scan0122 | |
| Arrangement to provide a production car chassis for experimental purposes. | 23th Feb 1920 | Box 77 \ 3 scan0123 | |
| Daily report on car 2.EX detailing runs, mechanical failures, and repairs from 19-02-1920 to 25-02-1920. | 25th Feb 1920 | Box 77 \ 3 scan0124 | |
| Adoption of aluminium pistons and investigating an engine knock issue. | 20th Feb 1920 | Box 77 \ 3 scan0125 | |
| Letter to Maddocks regarding rattling pistons on the 2EX chassis, suggesting carbon buildup as the cause and requesting an inspection. | 3rd Mar 1920 | Box 77 \ 3 scan0126 | |
| Adoption of split aluminium pistons for repair cars and investigating causes of engine knock. | 26th Feb 1920 | Box 77 \ 3 scan0127 | |
| Elusive engine knocks found in cars with the latest type of aluminium split pistons. | 2nd Mar 1920 | Box 77 \ 3 scan0128 | |
| Daily report log on car 2.EX, detailing a journey and maintenance from Feb 26th to March 4th. | 4th Mar 1920 | Box 77 \ 3 scan0129 | |
| Test driver's log from a continental trip detailing issues with tyres, piston rattles, and ignition, plus future journey plans. | 6th Aug 1919 | Box 77 \ 3 scan0130 | |
| | | | |
