| Description | Date | Identifier | |
| Letter to The Light Production Co. Ltd. concerning the design and production of compression rings. | 20th Oct 1937 | Box 148 \ 3 scan0275 | |
| Letter to The Light Production Co. Ltd. regarding an order for 144 piston rings and the testing of tin-plated pistons. | 25th Oct 1937 | Box 148 \ 3 scan0276 | |
| Order be placed with the Light Production Co. Ltd. for 144 compression rings. | 25th Oct 1937 | Box 148 \ 3 scan0277 | |
| Seven-step process for the tin plating of aluminium pistons. | 27th Oct 1937 | Box 148 \ 3 scan0278 | |
| Request to place an official order for various types of rings with Hepworth & Grandage Ltd. | 29th Nov 1937 | Box 148 \ 3 scan0279 | |
| Letter to Hepworth & Grandage Ltd. requesting the supply of piston rings based on attached drawings for a test car. | 29th Nov 1937 | Box 148 \ 3 scan0280 | |
| Letter discussing material specifications for special poundage piston rings for a 3.5' bore engine. | 2nd Dec 1937 | Box 148 \ 3 scan0281 | |
| Letter to Hepworth & Grandage Ltd. clarifying the ground finish requirement for rings and requesting a price for 6,000 units. | 3rd Dec 1937 | Box 148 \ 3 scan0282 | |
| Quotation from Hepworth & Grandage Ltd for piston and scraper rings. | 7th Dec 1937 | Box 148 \ 3 scan0283 | |
| Telegram confirming the despatch of rings. | 18th Dec 1937 | Box 148 \ 3 scan0284 | |
| Typed request to Rings, Bradford for a delivery date for rings. | 10th Dec 1937 | Box 148 \ 3 scan0285 | |
| Letter from Hepworth & Grandage Ltd. confirming a telegram about despatching rings. | 10th Dec 1937 | Box 148 \ 3 scan0286 | |
| Telegram confirming the dispatch of rings for order 53839. | 14th Dec 1937 | Box 148 \ 3 scan0287 | |
| Query regarding the non-receipt of rings dispatched to Kings, Bradford. | 14th Dec 1937 | Box 148 \ 3 scan0288 | |
| Letter from R. M. Papelian Ltd. proposing a trial of new 'Perfect Circle' piston rings on a Bentley engine. | 23th Dec 1937 | Box 148 \ 3 scan0289 | |
| Inquiry about the 'Ferrox Surface' treatment for piston rings mentioned in a Perfect Circle Piston Co. brochure. | 29th Dec 1937 | Box 148 \ 3 scan0290 | |
| Letter to Mr. Papelian discussing piston rings, oil consumption in the 4¼-litre Bentley, and a visit to the Perfect Circle Piston Co. in America. | 29th Dec 1937 | Box 148 \ 3 scan0291 | |
| Letter to a supplier regarding test results, manufacturing issues with 'L' section rings, and a request for more rings. | 31th Dec 1937 | Box 148 \ 3 scan0292 | |
| Page 2 of a letter regarding the supply and ordering of 'L' section rings made from various materials. | 31th Dec 1937 | Box 148 \ 3 scan0293 | |
| Letter from The Light Production Co. Ltd. regarding piston ring scuffing and surface treatments. | 3rd Jan 1938 | Box 148 \ 3 scan0294 | |
| Letter from a supplier discussing the manufacturing process and replacement of special rings. | 4th Jan 1938 | Box 148 \ 3 scan0295 | |
| Requesting an official order be placed with Hepworth & Grandage for various rings. | 7th Jan 1938 | Box 148 \ 3 scan0296 | |
| Letter placing an order for various types of rings for a standardisation test with Messrs. Hepworth & Grandage Ltd. | 7th Jan 1938 | Box 148 \ 3 scan0297 | |
| Letter to The Light Production Co. Ltd. regarding the tin plating and grinding of pistons. | 19th Jan 1938 | Box 148 \ 3 scan0298 | |
| Internal request to place an official order for tin plating three pistons for a Wraith chassis. | 20th Jan 1938 | Box 148 \ 3 scan0299 | |
| Requesting the despatch of three E.60632 pistons to the Light Production Co. Ltd. | 20th Jan 1938 | Box 148 \ 3 scan0300 | |
| Letter from Hepworth & Grandage Ltd. proposing the supply of 48 high-point compression rings for testing. | 21th Jan 1938 | Box 148 \ 3 scan0301 | |
| Letter to Hepworth & Grandage Ltd. discussing specifications for 48 compression rings, preferring a radial depth of .120 and enclosing drawing E.60820. | 24th Jan 1938 | Box 148 \ 3 scan0302 | |
| Letter from Hepworth & Grandage Ltd confirming specifications for compression rings. | 25th Jan 1938 | Box 148 \ 3 scan0303 | |
| Letter from The Light Production Co. Ltd. regarding the behaviour and supply of new heat-formed high poundage compression rings for an experimental engine. | 25th Jan 1938 | Box 148 \ 3 scan0304 | |
| Letter from The Light Production Co. Ltd. regarding the testing and properties of piston rings. | 25th Jan 1938 | Box 148 \ 3 scan0305 | |
| Letter to Messrs. Hepworth & Grandage Ltd. confirming an order for 48 high point rings. | 28th Jan 1938 | Box 148 \ 3 scan0306 | |
| Letter to The Light Production Co. Ltd. regarding 3 1/2' bore compression rings and T.slot pistons. | 28th Jan 1938 | Box 148 \ 3 scan0307 | |
| Letter regarding the dispatch of 8 Merlin engine pistons to The Light Production Co. Ltd. for tin plating experiments. | 4th Mar 1938 | Box 148 \ 3 scan0308 | |
| Letter requesting the tin plating of some R.R. pistons. | 4th Mar 1938 | Box 148 \ 3 scan0309 | |
| Letter from The Light Production Co. Ltd. regarding the tin-coating of 8 Merlin Pistons and the satisfactory results. | 7th Mar 1938 | Box 148 \ 3 scan0310 | |
| Letter concerning the 'Granoseal' process for treating Merlin piston rings and the tin-coating of pistons. | 7th Mar 1938 | Box 148 \ 3 scan0311 | |
| Page 2 of a letter to W.A. Robotham regarding an efficient crack detector for pistons. | 7th Mar 1938 | Box 148 \ 3 scan0312 | |
| Letter discussing the promising results of tin plating on car pistons to prevent scuffing. | 9th Mar 1938 | Box 148 \ 3 scan0313 | |
| Letter concerning the despatch and testing of tin-plated Merlin and car pistons. | 19th Mar 1938 | Box 148 \ 3 scan0314 | |
| Letter from The Light Production Co. Ltd. discussing the tin-coating process for Merlin and car pistons. | 22th Mar 1938 | Box 148 \ 3 scan0315 | |
| Letter from the General Manager of The Light Production Co. Ltd. regarding visits concerning Merlin rings. | 22th Mar 1938 | Box 148 \ 3 scan0316 | |
| Piston scuffing issues related to the use of different oil grades (S.A.E.20 vs. S.A.E.30). | 8th Apr 1938 | Box 148 \ 3 scan0317 | |
| The causes, findings, and recommendations related to piston scuffing in Wraith engines. | 5th Apr 1938 | Box 148 \ 3 scan0318 | |
| Method of testing for scuffed pistons and the performance of various oils. | 5th Apr 1938 | Box 148 \ 3 scan0319 | |
| Photograph showing the results of a piston scuffing test. | 5th Apr 1938 | Box 148 \ 3 scan0320 | |
| Photograph showing a scuffed piston after a piston scuffing test. | 5th Apr 1938 | Box 148 \ 3 scan0321 | |
| Photograph of a piston after undergoing scuffing tests. | 5th Apr 1938 | Box 148 \ 3 scan0322 | |
| Photograph and report of a piston scuffing test on a standard E.60632 piston. | 5th Apr 1938 | Box 148 \ 3 scan0323 | |
| Photograph showing a piston after a scuffing test with a report on the results. | 20th Apr 1938 | Box 148 \ 3 scan0324 | |
| Letter from Wellworthy Piston Rings Ltd. seeking advice on supplying RR.AC.6 bearings for an Ariel four-square engine. | 20th Apr 1938 | Box 148 \ 3 scan0325 | |
| Letter from Wellworthy Piston Rings Ltd. concerning the manufacture of crank-shaft bushes from blueprint No. 8033. | 20th Apr 1938 | Box 148 \ 3 scan0326 | |
| Letter from Wellworthy Piston Rings Ltd. to High Duty Alloys Ltd. regarding the casting of a Bristol Aero Co's bearing. | 20th Apr 1938 | Box 148 \ 3 scan0327 | |
| Letter from Wellworthy Piston Rings Ltd. to High Duty Alloys Ltd. clarifying the alloy specification for a bearing. | 11th Apr 1938 | Box 148 \ 3 scan0328 | |
| Letter from Wellworthy Piston Rings Ltd. to Ariel Motors Ltd. regarding a blueprint for a connecting rod and the use of RR.AC.6 material for bearings. | 13th Apr 1938 | Box 148 \ 3 scan0329 | |
| Letter from Wellworthy Piston Rings Ltd. regarding a superseded drawing and the omission of future etching. | 28th Apr 1938 | Box 148 \ 3 scan0330 | |
| Requesting the dispatch of six pistons to The Light Production Co. Ltd. for specific operations. | 2nd May 1938 | Box 148 \ 3 scan0331 | |
| Official order for grinding, tin-plating, and supply of T slot and aerolite Bentley pistons. | 2nd May 1938 | Box 148 \ 3 scan0332 | |
| Letter to The Light Production Co. Ltd. regarding the grinding and tin-plating of pistons, and an enquiry about a new ring treatment. | 2nd May 1938 | Box 148 \ 3 scan0333 | |
| Letter from The Light Production Co. Ltd. regarding piston regrinding, tin-coating, and ring scuffing. | 4th May 1938 | Box 148 \ 3 scan0334 | |
| Letter from a supplier discussing experiments with tin-coated pistons and rings to address high surface temperatures. | 6th May 1938 | Box 148 \ 3 scan0335 | |
| Letter to The Light Production Co., Ltd. regarding Ferrox treatment, tin-coated rings, and machining a spare T-slot piston for a 4 1/4 litre Bentley. | 6th May 1938 | Box 148 \ 3 scan0336 | |
| Request for a set of modified pistons for experimental purposes, seeking details on alterations and cost. | 6th May 1938 | Box 148 \ 3 scan0337 | |
| Letter to Briggs Bodies Ltd. discussing petrol tank specifications, material gauge, dimensions, and requesting a quote. | 5th Apr 1938 | Box 148 \ 3 scan0338 | |
| The examination and collection of returned pumps from Kingsbury and Cricklewood. | 6th May 1938 | Box 148 \ 3 scan0339 | |
| Requesting the dispatch of one piston to The Light Production Ltd. to be returned. | 10th May 1938 | Box 148 \ 3 scan0340 | |
| Brief typed communication, likely a telegram, arranging a visit to Wellworthy in Lymington. | 11th May 1938 | Box 148 \ 3 scan0341 | |
| Letter to a supplier regarding a manufacturing defect in 'L' section rings. | 11th May 1938 | Box 148 \ 3 scan0342 | |
| Letter from The Light Production Co. Ltd. regarding experimental pistons and associated costs. | 11th May 1938 | Box 148 \ 3 scan0343 | |
| Letter from The Light Production Co. Ltd. seeking approval on charges for work to be completed. | 12th May 1938 | Box 148 \ 3 scan0344 | |
| Letter from a supplier regarding the manufacturing method of 'L' section rings and a planned representative visit. | 12th May 1938 | Box 148 \ 3 scan0345 | |
| Letter to The Light Production Co. Ltd. regarding an order for raised crown pistons and arranging a meeting. | 14th May 1938 | Box 148 \ 3 scan0346 | |
| Official order for 14 modified pistons from Light Production Co. Ltd. | 16th May 1938 | Box 148 \ 3 scan0347 | |
| Letter to S.U. Carburetter Co. Ltd. inquiring about the supply and price of experimental Flower pistons. | 30th May 1938 | Box 148 \ 3 scan0348 | |
| Letter from S.U. Carburetter Co. Ltd. forwarding a query about pistons to Morris Motors Ltd. | 31th May 1938 | Box 148 \ 3 scan0349 | |
| Internal request to place an official order for 14 modified aerolite pistons from Light Production Co. Ltd. | 8th Jun 1938 | Box 148 \ 3 scan0350 | |
| Letter to Light Production Co. Ltd. requesting a delivery date and providing specifications for raised crown pistons. | 8th Jun 1938 | Box 148 \ 3 scan0351 | |
| Letter from The Light Production Co. Ltd. regarding a delay in the production of raised crown pistons. | 10th Jun 1938 | Box 148 \ 3 scan0352 | |
| Letter from The Light Production Co. Ltd. regarding the supply of pistons without flutes and a production timeline. | 14th Jun 1938 | Box 148 \ 3 scan0353 | |
| Confirming a conversation and requesting information on all available spare pistons and cylinders. | 9th Jul 1938 | Box 148 \ 3 scan0354 | |
| Letter to The Light Production Co. Ltd. to arrange a meeting about piston seizure issues. | 11th Jul 1938 | Box 148 \ 3 scan0355 | |
| Shortfall in an order for 14 Aerolite Pistons from a supplier. | 2nd Jul 1938 | Box 148 \ 3 scan0356 | |
| Confirming the acceptance of a piston order with one spare instead of two. | 5th Jul 1938 | Box 148 \ 3 scan0357 | |
| Approving the in-house tin-coating of pistons following successful tests. | 5th Jul 1938 | Box 148 \ 3 scan0358 | |
| Request to produce two sets of L section piston rings by modifying existing parts for despatch to Paris. | 6th Jul 1938 | Box 148 \ 3 scan0359 | |
| Modification drawing for an Aerolite Piston, referencing original drawing EB.3151. | 6th May 1938 | Box 148 \ 3 scan0360 | |
| Letter to The Light Production Co. Ltd. regarding the rescheduling of a visit due to a works holiday closure. | 15th Jul 1938 | Box 148 \ 3 scan0361 | |
| Letter from The Light Production Co. Ltd. acknowledging receipt of a communication and advising it will be passed to Mr. Brooks. | 18th Jul 1938 | Box 148 \ 3 scan0362 | |
| Letter from The British Piston Ring Co Ltd discussing patent specifications for Silcrome Steel and L-shaped rings. | 25th Jul 1938 | Box 148 \ 3 scan0363 | |
| Short letter from The British Piston Ring Co. Ltd. to Mr. Rowbotham. | 25th Jul 1938 | Box 148 \ 3 scan0364 | |
| Letter to The British Piston Ring Co. Ltd. proposing a meeting in Derby to discuss piston rings. | 29th Jul 1938 | Box 148 \ 3 scan0365 | |
| Letter to The Light Production Co. Ltd. requesting a further 14 modified experimental pistons with a raised crown. | 3rd Aug 1938 | Box 148 \ 3 scan0366 | |
| Letter from The Light Production Co. Ltd. acknowledging an order for fourteen pistons with a variation in dimension and advising of a delay. | 5th Aug 1938 | Box 148 \ 3 scan0367 | |
| The production of 12 pistons to be sent to an external company for final grinding. | 8th Aug 1938 | Box 148 \ 3 scan0368 | |
| Letter from the Experimental Department to Mr. C.H. Brooks arranging a visit. | 9th Aug 1938 | Box 148 \ 3 scan0369 | |
| Requesting an official order for 14 Aerolite pistons with a special raised crown. | 16th Aug 1938 | Box 148 \ 3 scan0370 | |
| Letter from The British Piston Ring Co Ltd proposing potential meeting dates. | 17th Aug 1938 | Box 148 \ 3 scan0371 | |
| Request for a new design of a raised crown piston to be compared against a similar Aerolite piston. | 17th Aug 1938 | Box 148 \ 3 scan0372 | |
| Letter to The Piston Ring Co., Ltd. arranging a visit for August 25th. | 18th Aug 1938 | Box 148 \ 3 scan0373 | |
| Piston seizures on Wraith & 25/30 models and recommended actions. | 19th Aug 1938 | Box 148 \ 3 scan0374 | |
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