| Description | Date | Identifier | |
| Laboratory report comparing the corrosion resistance of different aluminium alloys, particularly R.R.50, under various conditions. | 10th May 1933 | Box 148 \ 3 scan0075 | |
| Requesting the casting of sample pistons in EX.70 alloy to test its casting properties and strength. | 12th Jun 1933 | Box 148 \ 3 scan0076 | |
| Use of austenitic steel for a non-interference fit gudgeon pin. | 14th Jun 1933 | Box 148 \ 3 scan0077 | |
| Specifications for a set of test pistons for Phantom and Bentley engines to investigate mechanical efficiency at high speed. | 17th Jun 1933 | Box 148 \ 3 scan0078 | |
| Sketch of an experimental piston for Phantom 8 Litre and Bensport engines. | 16th Jun 1933 | Box 148 \ 3 scan0079 | |
| Testing of gudgeon pins without an interference fit. | 24th Oct 1933 | Box 148 \ 3 scan0080 | |
| The modification of a 20/25 chassis to test a cold-pushed gudgeon pin fit. | 1st Nov 1933 | Box 148 \ 3 scan0081 | |
| Necessity of removing brass inserts from aero engine bases before undergoing anodic treatment. | 17th Nov 1933 | Box 148 \ 3 scan0082 | |
| Developments in B.H.B. type pistons with the Automotive Engineering Co. | 22th Nov 1934 | Box 148 \ 3 scan0083 | |
| With diagrams comparing different piston designs and materials, based on notes from America. | 27th Nov 1934 | Box 148 \ 3 scan0084 | |
| Engine issues including cold knocking, piston design, oil consumption, and cylinder bores. | 27th Nov 1934 | Box 148 \ 3 scan0085 | |
| V8 manifold design, piston technology including American trends, and hydraulic shock absorbers. | 27th Nov 1934 | Box 148 \ 3 scan0086 | |
| Letter to The S.U. Company Ltd. requesting two dozen steel skirt pistons for testing. | 12th Dec 1934 | Box 148 \ 3 scan0087 | |
| Letter from The S.U. Company to W.A. Robotham acknowledging receipt of a letter and enclosure. | 17th Dec 1934 | Box 148 \ 3 scan0088 | |
| Letter providing engine specifications to The S.U. Carburetter Co. Ltd. | 21th Dec 1934 | Box 148 \ 3 scan0089 | |
| Letter to Messrs. Rudge Whitworth Ltd. inquiring about the working clearances for solid pistons. | 18th Jan 1935 | Box 148 \ 3 scan0090 | |
| Standardisation of R.R.59 Alloy Pistons for the Kestrel Engine, replacing the standard Y.Alloy. | 23th Jan 1935 | Box 148 \ 3 scan0091 | |
| Standardisation of R.R.59 alloy pistons for Kestrel engines. | 24th Jan 1935 | Box 148 \ 3 scan0092 | |
| Letter to the S.U. Company discussing the return of a piston drawing, power loss of a steel skirt piston, and costs for dies and tooling. | 16th Mar 1935 | Box 148 \ 3 scan0093 | |
| Letter discussing a design preference for a piston with a longer skirt. | 16th Mar 1935 | Box 148 \ 3 scan0094 | |
| Letter from The S.U. Company regarding pistons, power loss, and a piston drawing. | 18th Mar 1935 | Box 148 \ 3 scan0095 | |
| Letter from The S.U. Company regarding piston design, dimensions, and supply arrangements. | 21th Dec 1934 | Box 148 \ 3 scan0096 | |
| Letter to The S.U. Company Ltd. regarding the supply of pistons, gudgeon pins, and related drawings. | 19th Mar 1935 | Box 148 \ 3 scan0097 | |
| Letter from The S.U. Company regarding an arrangement for a meeting to sort out drawings. | 21th Mar 1935 | Box 148 \ 3 scan0098 | |
| Letter to The S.U. Company Ltd. regarding a sketch showing alternative conditions for a piston they are manufacturing. | 10th Apr 1935 | Box 148 \ 3 scan0099 | |
| Sketch showing the position of piston rings in relation to the water jacket for the Spectre engine. | 10th Apr 1935 | Box 148 \ 3 scan0100 | |
| Letter from The S.U. Company acknowledging receipt of a letter and two blueprints from the piston department. | 12th Apr 1935 | Box 148 \ 3 scan0101 | |
| Letter from The S.U. Company concerning piston delivery and a problem with casting thickness. | 28th May 1935 | Box 148 \ 3 scan0102 | |
| Letter to The S.U. Company Limited regarding the awaited arrival of pistons. | 30th May 1935 | Box 148 \ 3 scan0103 | |
| Request to supply S.U. Company with 2 dozen standard gudgeon pins for special Spectre pistons. | 6th Jun 1935 | Box 148 \ 3 scan0104 | |
| Internal request for a set of red 'Scarlet Runner' rear number plates. | 11th Jul 1935 | Box 148 \ 3 scan0105 | |
| Letter from the Experimental Department awaiting the arrival of steel skirted pistons. | 15th Jul 1935 | Box 148 \ 3 scan0106 | |
| Letter from The S.U. Company regarding a delay in the production and delivery of pistons. | 16th Jul 1935 | Box 148 \ 3 scan0107 | |
| Advice note detailing the dispatch of various piston components to The S.U. Company. | 30th Aug 1935 | Box 148 \ 3 scan0108 | |
| Letter to The Clews Petersen Piston Ring & Eng. Co. Ltd. requesting the supply of two dozen Clupet Scraper Rings. | 28th Oct 1935 | Box 148 \ 3 scan0109 | |
| Letter to The S.U. Company Ltd. regarding a seized steel skirted piston during testing. | 29th Oct 1935 | Box 148 \ 3 scan0110 | |
| Request to fit bushes to the Gudgeon Pin bores of a second set of S.U. pistons and mark them B-1. | 26th Nov 1935 | Box 148 \ 3 scan0111 | |
| Letter detailing the material analysis and hardness of hardened Piston Rings. | 27th Nov 1935 | Box 148 \ 3 scan0112 | |
| Letter from Rudge-Whitworth, Ltd. concerning the performance and heat treatment of piston rings. | 3rd Dec 1935 | Box 148 \ 3 scan0113 | |
| Letter from The S.U. Company confirming the despatch of six 82.55 m/m Pistons. | 3rd Dec 1935 | Box 148 \ 3 scan0114 | |
| Ordering, testing, and issues with steel skirted pistons for the Phantom 111. | 4th Dec 1935 | Box 148 \ 3 scan0115 | |
| Letter to The S.U. Company Ltd. confirming the receipt of 6 pistons. | 6th Dec 1935 | Box 148 \ 3 scan0116 | |
| Letter from The S.U. Company requesting engine data in relation to steel skirted pistons. | 19th Dec 1934 | Box 148 \ 3 scan0117 | |
| Letter to The S.U. Co. Ltd. concerning a lack of progress on steel skirted pistons. | 25th Feb 1936 | Box 148 \ 3 scan0118 | |
| Letter from The S.U. Company to W.A. Robotham regarding a meeting arrangement. | 26th Feb 1936 | Box 148 \ 3 scan0119 | |
| Concerning an invoice from the S.U. Company for pistons and dies, seeking payment approval. | 16th May 1936 | Box 148 \ 3 scan0120 | |
| Letter to The S.U. Company enclosing a power curve showing test results for their pistons. | 21th Apr 1936 | Box 148 \ 3 scan0121 | |
| Authorising payment for an invoice and part cost of dies. | 23th May 1936 | Box 148 \ 3 scan0122 | |
| Request to place an official order for Scraper and Compression Rings from Hepworth & Grandage Ltd. | 27th May 1936 | Box 148 \ 3 scan0123 | |
| Letter to Messrs. Hepworth & Grandage Ltd. requesting the supply of piston rings with detailed specifications. | 27th May 1936 | Box 148 \ 3 scan0124 | |
| Specifications and order instructions for stepped compression rings. | 27th May 1936 | Box 148 \ 3 scan0125 | |
| To Roy regarding an invoice for S.U. Pistons and a £40 payment towards the cost of dies. | 20th Jun 1936 | Box 148 \ 3 scan0126 | |
| Letter to Hepworth & Grandage Ltd. regarding the supply of piston rings, as recommended by the Chevrolet Engineering Company. | 28th May 1936 | Box 148 \ 3 scan0127 | |
| Invoice from S.U. Company for pistons and requesting a covering order for payment. | 18th Jun 1936 | Box 148 \ 3 scan0128 | |
| Letter to The Sealed Power Corporation regarding piston alterations based on their drawings and recommendations. | 24th Jun 1936 | Box 148 \ 3 scan0129 | |
| Letter to Wellworthy Ltd. explaining a delay in despatching 12 pistons due to a production hold-up. | 17th Jul 1936 | Box 148 \ 3 scan0130 | |
| Letter to Wellworthy Piston Rings Ltd. regarding a proposal to test their Simplex rings on a Rolls-Royce engine. | 28th Jul 1936 | Box 148 \ 3 scan0131 | |
| Letter to L. Pomeroy of The De Havilland Aircraft Co. Ltd. requesting information on Simplex piston rings. | 28th Jul 1936 | Box 148 \ 3 scan0132 | |
| Letter from De Havilland discussing the merits of the Wellworthy piston ring and its application in sleeve valve engines. | 29th Jul 1936 | Box 148 \ 3 scan0133 | |
| Page two of a letter to The de Havilland Aircraft Co. Ltd. concerning sleeve valve Daimlers. | 29th Jul 1936 | Box 148 \ 3 scan0134 | |
| Letter to Wellworthy Ltd. regarding the despatch of two sets of pistons for testing on a 25/30 unit and a Bentley unit. | 30th Jul 1936 | Box 148 \ 3 scan0135 | |
| Letter to L.H. Pomeroy of De Havilland Aircraft Co. Ltd. regarding Wellworthy piston rings. | 30th Jul 1936 | Box 148 \ 3 scan0136 | |
| Instructing the despatch of pistons to Wellworthy Ltd. | 30th Jul 1936 | Box 148 \ 3 scan0137 | |
| Letter from Specialloid Ltd. to Messrs. Rolls Royce regarding Specialloid Pistons and their recent successes in high-efficiency cars. | 30th Jul 1936 | Box 148 \ 3 scan0138 | |
| Letter from parts supplier Specialloid Limited regarding the supply of pistons. | 30th Jul 1936 | Box 148 \ 3 scan0139 | |
| Concluding page of a letter from Specialloid Limited to Messrs. Rolls Royce Ltd. | 30th Jul 1936 | Box 148 \ 3 scan0140 | |
| List of successes by English Racing Automobiles cars using Specialloid pistons during the 1935 racing season. | 1st Jun 1936 | Box 148 \ 3 scan0141 | |
| List of motor racing results for E.R.A. cars from various events in 1935 and 1936. | 31th Jul 1936 | Box 148 \ 3 scan0142 | |
| Letter to Messrs. Specialloid Ltd. declining to undertake further tests on Specialloid Pistons due to other commitments. | 31th Jul 1936 | Box 148 \ 3 scan0143 | |
| Laboratory photomicrograph comparing 'Plain', 'Slotted', and 'Wellworthy' samples at 500x magnification. | 1st Oct 1935 | Box 148 \ 3 scan0144 | |
| Letter from De Havilland to Mr. Robotham discussing increased engine oil consumption following decarbonisation. | 31th Jul 1936 | Box 148 \ 3 scan0145 | |
| Letter from piston manufacturer Specialloid Limited regarding the testing of their pistons. | 4th Aug 1936 | Box 148 \ 3 scan0146 | |
| Letter from Wellworthy Piston Rings Ltd apologising for a postal error. | 5th Aug 1936 | Box 148 \ 3 scan0147 | |
| Letter to Wellworthy Piston Ring Co. Ltd. regarding a missing communication intended for Bristol Aeroplane Co. Ltd. | 7th Aug 1936 | Box 148 \ 3 scan0148 | |
| Letter from a piston specialist regarding 4.5L Bentley pistons, specifically discussing side clearance on scraper rings to improve oil consumption. | 24th Aug 1936 | Box 148 \ 3 scan0149 | |
| Letter discussing piston ring clearances, excessive oiling, and the potential use of Simplex piston rings. | 24th Aug 1936 | Box 148 \ 3 scan0150 | |
| Continuation page of a letter from Wellworthy Piston Rings Limited. | 24th Aug 1936 | Box 148 \ 3 scan0151 | |
| Letter to Messrs. Wellworthy Ltd. regarding ongoing investigations into oil consumption and piston ring combinations. | 26th Aug 1936 | Box 148 \ 3 scan0152 | |
| Letter to the Wellworthy Piston Ring Co. Ltd. regarding the development and supply of Aerolite pistons for a 4¼ litre Bentley. | 31th Aug 1936 | Box 148 \ 3 scan0153 | |
| Booking in of Piston Rings received from Mr. Blackith of Wellworthy Ltd. | 1st Sep 1936 | Box 148 \ 3 scan0154 | |
| Letter to Wellworthy Ltd. discussing piston ring clearances and oil consumption issues for Bentley and 25/30 engines. | 1st Sep 1936 | Box 148 \ 3 scan0155 | |
| Page 2 of a letter discussing the trial of Aerolite pistons and seized piston figures. | 1st Sep 1936 | Box 148 \ 3 scan0156 | |
| Letter from Wellworthy Piston Rings regarding the fitting of their pistons to a 4 1/4' Bentley. | 1st Sep 1936 | Box 148 \ 3 scan0157 | |
| Letter to Messrs. Wellworthy Ltd. arranging a visit to test three cylinder blocks on their profileograph. | 6th Oct 1936 | Box 148 \ 3 scan0158 | |
| Letter to The Perfect Circle Ring Co. in the U.S.A. asking for help with engine oil consumption problems. | 13th Oct 1936 | Box 148 \ 3 scan0159 | |
| Raising questions and discussing test results regarding the radial thickness and pressure of engine rings, comparing them to American standards. | 13th Oct 1936 | Box 148 \ 3 scan0160 | |
| The performance and design of piston rings, including ring finish, scraper rings, and bevel rings. | 13th Oct 1936 | Box 148 \ 3 scan0161 | |
| Series of questions regarding the optimal design and specifications for piston rings. | 13th Oct 1936 | Box 148 \ 3 scan0162 | |
| Technical query comparing British and American manufacturing methods for engine components like rings, pistons and cylinders. | 13th Oct 1936 | Box 148 \ 3 scan0163 | |
| Letter requesting information on acceptable cylinder bore irregularities and its effect on oil consumption. | 13th Oct 1936 | Box 148 \ 3 scan0164 | |
| Circulating a new catalogue from the Wellworthy Piston Ring Company. | 4th Nov 1936 | Box 148 \ 3 scan0165 | |
| Letter to Wellworthy Piston Rings Ltd. requesting to borrow a profilegraph instrument for use on cylinder blocks. | 5th Nov 1936 | Box 148 \ 3 scan0166 | |
| Letter from Wellworthy Piston Rings discussing measuring errors in cylinder walls. | 11th Nov 1936 | Box 148 \ 3 scan0167 | |
| Oil consumption test, decarbonisation, and piston ring fitting for car GUL 1. | 13th Nov 1936 | Box 148 \ 3 scan0168 | |
| Letter from Hepworth & Grandage Ltd discussing cylinder materials, liners, and a former employee. | 16th Nov 1936 | Box 148 \ 3 scan0169 | |
| Continuation of a letter from Hepworth & Grandage Ltd. regarding data from actual tests. | 16th Nov 1936 | Box 148 \ 3 scan0170 | |
| List of firms fitting 'VACRIT' liners as standard and other users of the liners. | 1st Aug 1936 | Box 148 \ 3 scan0171 | |
| Typed list of various companies, councils, and transport departments with their locations. | 9th Nov 1936 | Box 148 \ 3 scan0172 | |
| Letter from The Perfect Circle Company acknowledging receipt of correspondence and explaining a delay in response. | 9th Nov 1936 | Box 148 \ 3 scan0173 | |
| Letter to The Light Production Co. Ltd. requesting technical specifications and pricing for 'D' type scraper rings for standardisation purposes. | 10th Nov 1936 | Box 148 \ 3 scan0174 | |
| | | | |
