| Description | Date | Identifier | |
| Proposal received from The British Piston Ring Co. Ltd. to produce Piston Rings in Tungum Alloy. | 18th Nov 1936 | Box 148 \ 3 scan0175 | |
| Letter from The British Piston Ring Co. Ltd. discussing the suitability of Tungum Alloy for aero engine rings. | 17th Nov 1936 | Box 148 \ 3 scan0176 | |
| The chemical composition and hardness specifications for piston rings and cylinders, comparing American standards with internal ones. | 19th Nov 1936 | Box 148 \ 3 scan0177 | |
| Technical note on cylinder materials, lubricants, and the performance and design of piston rings under heat. | 19th Nov 1936 | Box 148 \ 3 scan0178 | |
| Report page detailing tests and conclusions on engine cylinder and piston ring wear, materials, and hardness. | 19th Nov 1936 | Box 148 \ 3 scan0179 | |
| List of conclusions regarding engine ring and cylinder operation, wear, and testing. | 13th Nov 1936 | Box 148 \ 3 scan0180 | |
| Letter from The Light Production Co. Ltd. providing specifications and pricing for 'D' type Scraper Rings. | 13th Nov 1936 | Box 148 \ 3 scan0181 | |
| Request for two sets of modified pistons and a query regarding high-pressure scraper ring wear. | 20th Nov 1936 | Box 148 \ 3 scan0182 | |
| Requesting an official order be placed for pistons and rings with the Light Production Co. Ltd. | 20th Nov 1936 | Box 148 \ 3 scan0183 | |
| Letter from The Light Production Co. Ltd. to the Experimental Dept. regarding pistons, scraper rings, and wear. | 23th Nov 1936 | Box 148 \ 3 scan0184 | |
| Page 2 of a letter from The Light Production Co. Ltd. regarding cylinder material suitability for a type of ring. | 23th Nov 1936 | Box 148 \ 3 scan0185 | |
| Letter from The Light Production Co. Ltd. regarding a modified piston skirt form for oil control. | 30th Nov 1936 | Box 148 \ 3 scan0186 | |
| Letter from The Light Production Co. Ltd. discussing piston experiments, oil consumption and scraper rings. | 1st Dec 1936 | Box 148 \ 3 scan0187 | |
| Letter from The Light Production Co. Ltd. regarding the despatch of piston ring components for a 3 1/4' bore Bentley engine. | 1st Dec 1936 | Box 148 \ 3 scan0188 | |
| Letter from a supplier confirming the dispatch of 12 urgently required pistons in response to a telegram. | 8th Dec 1936 | Box 148 \ 3 scan0189 | |
| Urgent telegram requesting early delivery for 12 outstanding pistons. | 7th Dec 1936 | Box 148 \ 3 scan0190 | |
| Telegram received by telephone regarding the dispatch of twelve pistons. | 8th Dec 1936 | Box 148 \ 3 scan0191 | |
| Telegram confirming the despatch of twelve pistons against an advice note. | 8th Dec 1939 | Box 148 \ 3 scan0192 | |
| Request to The British Piston Ring Co. Ltd. for the supply of 20 piston rings to drawing E.61267. | 9th Dec 1936 | Box 148 \ 3 scan0193 | |
| Order to be placed for 20 F.61267 piston rings. | 10th Dec 1936 | Box 148 \ 3 scan0194 | |
| Letter from a director of Wellworthy Piston Rings to H. Royce, expressing delight with his new Bentley. | 17th Dec 1936 | Box 148 \ 3 scan0195 | |
| Micro-examination report and photomicrograph of a Wellworthy piston ring for a Bentley chassis. | 30th Dec 1936 | Box 148 \ 3 scan0196 | |
| Confirming experiments to be carried out for the tin plating of aluminium pistons at various thicknesses. | 26th Jan 1937 | Box 148 \ 3 scan0197 | |
| Letter from The Birmingham Aluminium Casting Company regarding the production and supply of Nelson Bohnalite Autothermic Pistons. | 1st Feb 1937 | Box 148 \ 3 scan0198 | |
| Letter to The Birmingham Aluminium Casting Co. Ltd. regarding Piston Drawing No. E60632. | 3rd Feb 1937 | Box 148 \ 3 scan0199 | |
| Letter from Birmingham Aluminium Casting Co. Ltd. acknowledging receipt of piston drawing E.60632 and advising a design and price will follow. | 4th Feb 1937 | Box 148 \ 3 scan0200 | |
| Letter from Birmingham Aluminium Casting Co. Ltd. seeking clarification on a gudgeon pin design for piston drawing E.60632. | 9th Feb 1937 | Box 148 \ 3 scan0201 | |
| Request to Light Production Co. Ltd. for the supply of 48 Scraper Rings with specific properties. | 9th Feb 1937 | Box 148 \ 3 scan0202 | |
| Letter to The Birmingham Aluminium Co. Ltd. clarifying the use of a fully floating Gudgeon pin with end pads in a piston design. | 11th Feb 1937 | Box 148 \ 3 scan0203 | |
| Letter from The Birmingham Aluminium Casting Co Ltd. regarding the design and quote for a gudgeon pin. | 12th Feb 1937 | Box 148 \ 3 scan0204 | |
| Letter regarding a new design for an Autothermic Piston to replace design E.60632. | 18th Feb 1937 | Box 148 \ 3 scan0205 | |
| Letter clarifying the ground finish required for 3.5 litre Bentley rings and addressing communication issues with the supplier. | 19th Feb 1937 | Box 148 \ 3 scan0206 | |
| Quotation from The Birmingham Aluminium Casting Co. for the supply of Autothermic pistons, rings, and gudgeon pins. | 23th Feb 1937 | Box 148 \ 3 scan0207 | |
| Letter to Birmingham Aluminium Casting Co. Ltd. regarding piston design, costs and a proposed visit. | 2nd Mar 1937 | Box 148 \ 3 scan0208 | |
| Letter from The Birmingham Aluminium Casting Company regarding Autothermic Pistons and a meeting arrangement. | 3rd Mar 1937 | Box 148 \ 3 scan0209 | |
| Letter to The Birmingham Aluminium Casting Co. Ltd. arranging a meeting to discuss piston problems. | 5th Mar 1937 | Box 148 \ 3 scan0210 | |
| Letter from The Birmingham Aluminium Casting Company Ltd. confirming a meeting to discuss a piston proposition. | 8th Mar 1937 | Box 148 \ 3 scan0211 | |
| Official order for scraper and compression rings for Bentley engines. | 10th Mar 1937 | Box 148 \ 3 scan0212 | |
| Letter to The Light Production Co. Ltd. requesting the supply of high pressure scraper rings and compression rings for a 4 1/4 litre Bentley. | 10th Mar 1937 | Box 148 \ 3 scan0213 | |
| Letter from The Birmingham Aluminium Casting Co. Ltd. regarding the production and costing of piston dies. | 12th Mar 1937 | Box 148 \ 3 scan0214 | |
| Letter from Birmingham Aluminium Casting Co. Ltd. regarding the dispatch of a 'Cylinder Bore Wear' book and a Technical Data Book. | 12th Mar 1937 | Box 148 \ 3 scan0215 | |
| Official order for experimental pistons from the Birmingham Aluminium Casting Co Ltd. | 15th Mar 1937 | Box 148 \ 3 scan0216 | |
| Letter to The Birmingham Aluminium Casting Co. Ltd. confirming an order for experimental pistons. | 16th Mar 1937 | Box 148 \ 3 scan0217 | |
| Letter from The Birmingham Aluminium Casting Co. Ltd. confirming the production of experimental pistons. | 17th Mar 1937 | Box 148 \ 3 scan0218 | |
| Supply, pricing, and alloy specifications for experimental Autothermic pistons. | 19th Mar 1937 | Box 148 \ 3 scan0219 | |
| Letter to Messrs. Hepworth & Grandage Ltd. to arrange a meeting to discuss piston rings and cylinder liners. | 16th Apr 1937 | Box 148 \ 3 scan0220 | |
| Letter confirming an appointment at Hepworth & Grandage Ltd's works. | 20th Apr 1937 | Box 148 \ 3 scan0221 | |
| Letter to a supplier enclosing piston ring drawings and requesting cost and material specifications. | 26th Apr 1937 | Box 148 \ 3 scan0222 | |
| Letter to the Birmingham Aluminium Casting Co., Ltd. regarding the delivery and design of Autothermic Pistons. | 15th May 1937 | Box 148 \ 3 scan0223 | |
| Telegram received by telephone regarding the availability of test pistons. | 24th May 1937 | Box 148 \ 3 scan0224 | |
| Telegram to Birmal in Smethwick chasing up the development of pistons. | 24th May 1937 | Box 148 \ 3 scan0225 | |
| Letter from Birmingham Aluminium Casting Co. Ltd. regarding a delay in the development and supply of pistons. | 24th May 1937 | Box 148 \ 3 scan0226 | |
| Letter to C.H. Brooks of The Light Production Co., Ltd. regarding serious piston failures on a customer's car and a Bentley. | 28th May 1937 | Box 148 \ 3 scan0227 | |
| Letter from The Light Production Co. Ltd. arranging a meeting to discuss a piston failure on a customer's car. | 29th May 1937 | Box 148 \ 3 scan0228 | |
| Letter to The Light Production Co. Ltd. discussing piston clearances and temperature calculations for a new set of pistons. | 5th Jun 1937 | Box 148 \ 3 scan0229 | |
| Official order for a set of 4 1/2 litre Bentley pistons from Light Production Co. Ltd. | 5th Jun 1937 | Box 148 \ 3 scan0230 | |
| Letter from The Light Production Co. Ltd. discussing piston and gudgeon pin clearances. | 8th Jun 1937 | Box 148 \ 3 scan0231 | |
| Letter from The Light Production Co. Ltd. regarding connecting-rod pressure markings and potential piston failures. | 8th Jun 1937 | Box 148 \ 3 scan0232 | |
| The dispatch of engine components for a Bentley 4¼ litre engine, including a cylinder block, pistons, and various rings. | 7th Jun 1937 | Box 148 \ 3 scan0233 | |
| Letter from a supplier regarding delays in producing experimental Autothermic Pistons due to a defective casting. | 7th Jun 1937 | Box 148 \ 3 scan0234 | |
| 1937 summer meeting visit to German engineering factories, detailing observations and restrictions encountered. | 21th Jun 1937 | Box 148 \ 3 scan0235 | |
| Observations on Opel's manufacturing processes, integral body construction, and 2-litre 6-cylinder engine design. | 21th Jun 1937 | Box 148 \ 3 scan0236 | |
| Technical report on Opel cylinder heads and a visit to Elektronmetall to observe piston technology. | 21th Jun 1937 | Box 148 \ 3 scan0237 | |
| Report page detailing piston manufacturing, testing, and laboratory equipment at Elektronmetall, and a brief note on a visit to Robert Bosch A.G. | 21th Jun 1937 | Box 148 \ 3 scan0238 | |
| Daimler-Benz vehicle technology, including frame construction, engine design, and a review of a V-12 supercharged engine. | 21th Jun 1937 | Box 148 \ 3 scan0239 | |
| Technical note on Daimler-Benz and Gasmotorenfabrik Deutz engines. | 21th Jun 1937 | Box 148 \ 3 scan0240 | |
| Blueprint showing a cross-section and inverted plan of a cylinder head for a new 2-litre Opel engine. | 21th Jun 1937 | Box 148 \ 3 scan0241 | |
| Diagram showing oil drillings in an aero piston from Elektronmetall G.M.B.H., Canstatt. | 21th Jun 1937 | Box 148 \ 3 scan0242 | |
| Sketch of an Opel rear main bearing cap, showing plan and section views. | 24th Jun 1937 | Box 148 \ 3 scan0243 | |
| Letter from a supplier regarding the manufacture and delivery of experimental autothermatic pistons. | 24th Jun 1937 | Box 148 \ 3 scan0244 | |
| Copy document from Hepworth & Grandage detailing the chemical composition of suggested ring materials for testing. | 30th Apr 1937 | Box 148 \ 3 scan0245 | |
| Request to despatch 14 pistons to The Light Production Co. Ltd. for machining. | 6th Jul 1937 | Box 148 \ 3 scan0246 | |
| Requesting an official order for machining 14 pistons for Bentley. | 6th Jul 1937 | Box 148 \ 3 scan0247 | |
| Letter to The Light Production Co. Ltd. regarding the despatch and modification of pistons. | 6th Jul 1937 | Box 148 \ 3 scan0248 | |
| Returning compression and scraper rings to the supplier, Hepworth & Grandage Ltd., for sorting due to missing identification marks. | 8th Jul 1937 | Box 148 \ 3 scan0249 | |
| Letter to a supplier returning unidentified rings for sorting and discussing a new gauge for measuring ring periphery. | 8th Jul 1937 | Box 148 \ 3 scan0250 | |
| Request to Penn Birmal Smethwick for six spare scraper rings for Autothermic pistons. | 3rd Aug 1937 | Box 148 \ 3 scan0251 | |
| Requesting an official order be placed for 6 scraper rings for Autothermic pistons for the Wraith Chassis. | 5th Aug 1937 | Box 148 \ 3 scan0252 | |
| Letter to Hepworth & Grandage Ltd. regarding a mix-up with engine rings and a request for analysis and identification markings. | 9th Aug 1937 | Box 148 \ 3 scan0253 | |
| Letter requesting the urgent supply of 50 compression rings for a 3½ litre Bentley engine. | 23th Aug 1937 | Box 148 \ 3 scan0254 | |
| Instruction to place an official order for 50 Bentley compression rings with specifications. | 23th Aug 1937 | Box 148 \ 3 scan0255 | |
| Letter from The Light Production Co. Ltd. regarding the manufacture of fifty Compression Rings. | 25th Aug 1937 | Box 148 \ 3 scan0256 | |
| Letter from The Light Production Co. Ltd. confirming a delivery schedule. | 25th Aug 1937 | Box 148 \ 3 scan0257 | |
| Letter to Hepworth & Grandage Ltd. regarding an analysis of rings and placing a new order for compression rings. | 30th Aug 1937 | Box 148 \ 3 scan0258 | |
| Request to place an order for Bentley piston rings with Hepworth and Grandage Ltd. | 30th Aug 1937 | Box 148 \ 3 scan0259 | |
| Letter to Birmingham Aluminium Casting Co. Ltd. regarding preliminary tests on Autothermic Pistons and arranging a follow-up meeting. | 1st Sep 1937 | Box 148 \ 3 scan0260 | |
| Urgent request for high pressure Bentley compression rings from Light Production Co. Ltd. | 3rd Sep 1937 | Box 148 \ 3 scan0261 | |
| Telegram received by telephone confirming the dispatch of high pressure rings. | 6th Sep 1937 | Box 148 \ 3 scan0262 | |
| Letter to Messrs. Hepworth & Grandage Ltd. regarding a discrepancy in wall pressure calculations for a valve ring. | 8th Sep 1937 | Box 148 \ 3 scan0263 | |
| Letter to The Birmingham Aluminium Casting Co. Ltd. to arrange a meeting to discuss pistons. | 10th Sep 1937 | Box 148 \ 3 scan0264 | |
| Letter from The Birmingham Aluminium Casting Co Ltd to arrange a meeting on the upcoming Thursday. | 11th Sep 1937 | Box 148 \ 3 scan0265 | |
| Letter to The Birmingham Aluminium Casting Co. Ltd. confirming a meeting. | 14th Sep 1937 | Box 148 \ 3 scan0266 | |
| Telegram confirming the dispatch of high pressure rings to the Experimental Department. | 6th Sep 1937 | Box 148 \ 3 scan0267 | |
| Requesting an official order for 144 rings from Light Production Co. Ltd for six Wraith cars in production. | 6th Oct 1937 | Box 148 \ 3 scan0268 | |
| Letter to Light Production Co. Ltd. requesting the supply of 144 rings with specific modifications for a Bentley engine. | 6th Oct 1937 | Box 148 \ 3 scan0269 | |
| Letter from The Light Production Co. Ltd. regarding the manufacture of 144 piston rings to Drawing No.E.W.1425. | 8th Oct 1937 | Box 148 \ 3 scan0270 | |
| Letter accepting an invitation to lunch and to visit a stand at a show. | 11th Oct 1937 | Box 148 \ 3 scan0271 | |
| Request to despatch six aerolite pistons to Light Production Co. Ltd. for attention. | 15th Oct 1937 | Box 148 \ 3 scan0272 | |
| Request for an official order to be sent to Light Production Co. Ltd. for the tin plating of six Aerolite Pistons for use on a Bentley chassis. | 15th Oct 1937 | Box 148 \ 3 scan0273 | |
| Letter to Light Production Co. Ltd. regarding the despatch of six pistons for tin plating. | 15th Oct 1937 | Box 148 \ 3 scan0274 | |
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