| Description | Date | Identifier | |
| Letter from The Light Production Co. Ltd. regarding RR.53 castings and the inclusion of a complimentary refitted piston. | 4th Jul 1934 | Box 86 \ 2 scan0230 | |
| Use, benefits, and proposed testing of anodically treated aluminium pistons. | 4th Jul 1934 | Box 86 \ 2 scan0231 | |
| The investigation into anodically treated pistons and related aluminium alloys. | 5th Jul 1934 | Box 86 \ 2 scan0232 | |
| Letter regarding the progress and difficulties of applying anodic treatment to RR.53 alloy pistons. | 7th Jul 1934 | Box 86 \ 2 scan0233 | |
| The second page of a letter urging for a quick response to move a matter forward. | 7th Jul 1934 | Box 86 \ 2 scan0234 | |
| Letter from The Light Production Co. Ltd. discussing unsatisfactory experimental work on the anodic treatment of RR.53 and RR.52 alloys. | 9th Jul 1934 | Box 86 \ 2 scan0235 | |
| Letter from The Light Production Co. Ltd. discussing the progress and expected results of material treatment. | 9th Jul 1934 | Box 86 \ 2 scan0236 | |
| Inquiry to Brookes, Aerolite Pistons Co., regarding when pistons will be ready for collection. | 9th Jul 1934 | Box 86 \ 2 scan0237 | |
| Difficulties in getting results from Alumilite Co. Ltd. for the anodical treatment of RR.53 alloy pistons. | 12th Jul 1934 | Box 86 \ 2 scan0238 | |
| Letter discussing a conversation about expected test results from a third party within a fortnight. | 12th Jul 1934 | Box 86 \ 2 scan0239 | |
| Quotation for Aerolite Pistons from The Light Production Co. Ltd. | 12th Jul 1934 | Box 86 \ 2 scan0240 | |
| Authorising the order of Aerolite Pistons for the Spectre. | 16th Jul 1934 | Box 86 \ 2 scan0241 | |
| Complexities of producing an oxidised coating on anodically treated pistons made from R.R.53 alloy. | 21th Jul 1934 | Box 86 \ 2 scan0242 | |
| Letter regarding an order for 'Aerolite' Pistons being held in an unground condition awaiting further instructions. | 24th Jul 1934 | Box 86 \ 2 scan0243 | |
| Letter to a supplier regarding pistons that have cracked during high-speed running tests. | 7th Aug 1934 | Box 86 \ 2 scan0244 | |
| Letter from The Light Production Co. Ltd. acknowledging a communication and explaining a delay due to a works holiday closure. | 8th Aug 1934 | Box 86 \ 2 scan0245 | |
| Letter from The Light Production Co. Ltd. concerning piston cracking in 122 alloy and new die modifications for RR.53 castings. | 22th Aug 1934 | Box 86 \ 2 scan0246 | |
| Letter expressing dissatisfaction with the lack of progress from the Alumilite people regarding project RR.53. | 27th Aug 1934 | Box 86 \ 2 scan0247 | |
| Letter to The Light Production Co. Ltd. concerning the replacement of failed RR.53 pistons and testing an alternative supply for alumiliting. | 27th Aug 1934 | Box 86 \ 2 scan0248 | |
| Letter regarding cracked alloy pistons after 15,000 miles of testing and a request for replacements. | 3rd Sep 1934 | Box 86 \ 2 scan0249 | |
| Letter specifying grinding dimensions and arranging a follow-up meeting. | 3rd Sep 1934 | Box 86 \ 2 scan0250 | |
| Letter from The Light Production Co. Ltd. discussing cracks in RR.53 castings for Aerolite Pistons. | 5th Sep 1934 | Box 86 \ 2 scan0251 | |
| Alloy casting issues, potential solutions, deliveries, and anodising experiments. | 5th Sep 1934 | Box 86 \ 2 scan0252 | |
| Page three of a letter from The Light Production Co. Ltd. regarding a patent specification and pistons for testing. | 6th Sep 1934 | Box 86 \ 2 scan0253 | |
| Letter to Mr. Brookes at The Light Production Co. Ltd. discussing the standardisation of Aerolite pistons for Bentley cars. | 6th Sep 1934 | Box 86 \ 2 scan0254 | |
| Request to measure Aerolite pistons removed from a 10,000-mile Bentley unit. | 17th Sep 1934 | Box 86 \ 2 scan0255 | |
| Requesting the measurement of Aerolite pistons removed from a 10,000 mile Bentley unit. | 17th Sep 1934 | Box 86 \ 2 scan0256 | |
| Table of dimensions for 'Aerolite' pistons taken before and after 10,000-mile trials. | 19th Sep 1939 | Box 86 \ 2 scan0257 | |
| Order for two Aerolite Pistons for Bentley from the Light Production Co. Ltd. | 18th Sep 1934 | Box 86 \ 2 scan0258 | |
| Request to measure and chalk test Aerolite pistons from Y4BB and B-4 units. | 20th Sep 1934 | Box 86 \ 2 scan0259 | |
| Request to manufacture two sets of Bentley pistons using existing castings based on specific drawings. | 24th Sep 1934 | Box 86 \ 2 scan0260 | |
| Letter from The Light Production Co. Ltd. concerning the delivery and specifications of Aerolite pistons. | 25th Sep 1934 | Box 86 \ 2 scan0261 | |
| Request to manufacture two sets of pistons for Bentley & 20/25 models. | 26th Sep 1934 | Box 86 \ 2 scan0262 | |
| Arrival and fitting of Aerolite Pistons for the Spectre. | 27th Sep 1934 | Box 86 \ 2 scan0263 | |
| Requesting orders be placed with the Light Production Co. for two sets of 6 Bentley pistons. | 3rd Oct 1934 | Box 86 \ 2 scan0264 | |
| Invoice for Aerolite Pistons from the Light Production Co. Ltd. | 2nd Oct 1934 | Box 86 \ 2 scan0265 | |
| Despatch of two Aerolite Pistons to the Light Production Co. Ltd. for examination. | 10th Oct 1934 | Box 86 \ 2 scan0266 | |
| To cease work on semi-split type pistons in favour of the successful Aerolite pistons for Bentley and 20/25 models. | 12th Oct 1934 | Box 86 \ 2 scan0267 | |
| Letter concerning a disputed invoice for anodising pistons supplied for experimental work. | 12th Oct 1934 | Box 86 \ 2 scan0268 | |
| Invoice from The London Piston Ring Co., Ltd. for anodising 6 pistons. | 11th Oct 1934 | Box 86 \ 2 scan0269 | |
| The ordering, credit, and supply of Bentley pistons in RR.53 alloy. | 15th Oct 1934 | Box 86 \ 2 scan0270 | |
| Dimensional chart for 'Aerolite' pistons from a Bentley 4 Unit engine. | 1st Oct 1934 | Box 86 \ 2 scan0271 | |
| Measurement log for 'Aerolite' pistons, detailing dimensions at various points on the ring lands and skirt. | 1st Oct 1934 | Box 86 \ 2 scan0272 | |
| Letter from The Light Production Co. Ltd. discussing the invoicing procedure for six anodised pistons supplied for research purposes. | 15th Oct 1934 | Box 86 \ 2 scan0273 | |
| Page 2 of a letter from The Light Production Co. Ltd. requesting a response. | 23th Oct 1934 | Box 86 \ 2 scan0274 | |
| Requesting the fitting of anodically treated pistons to a scrap engine unit for testing. | 23th Oct 1934 | Box 86 \ 2 scan0275 | |
| Letter to The Light Production Co. Ltd. clarifying the procedure for invoicing experimental parts supplied for research. | 24th Oct 1934 | Box 86 \ 2 scan0276 | |
| Standardisation of parts for Aerolite Pistons. | 9th Aug 1934 | Box 86 \ 2 scan0277 | |
| Proposal for introducing a bought-out unit for the 'D' series chassis without incurring tool costs. | 25th Sep 1934 | Box 86 \ 2 scan0278 | |
| Letter from The Light Production Co. Ltd. regarding a credit for six Anodised Pistons supplied for experimental purposes. | 26th Oct 1934 | Box 86 \ 2 scan0279 | |
| Urgent request to order 12 Gas rings for Aerolite Pistons from the Light Production Co. | 31th Oct 1934 | Box 86 \ 2 scan0280 | |
| Letter to The Light Production Co. Ltd. regarding the return of faulty pistons and requesting replacements. | 1st Nov 1934 | Box 86 \ 2 scan0281 | |
| Anodic oxidation of RR.53 pistons. | 1st Nov 1934 | Box 86 \ 2 scan0282 | |
| Laboratory report on low-voltage anodic oxidation experiments conducted on R.R.53 pistons. | 22th Oct 1934 | Box 86 \ 2 scan0283 | |
| Letter to The Light Production Co. Ltd. requesting two spare pistons due to unsatisfactory bedding on a supplied set. | 2nd Nov 1934 | Box 86 \ 2 scan0284 | |
| Letter from The Light Production Co. Ltd. concerning piston weight discrepancies and machining. | 5th Nov 1934 | Box 86 \ 2 scan0285 | |
| Letter from The Light Production Co. Ltd. discussing production specifications and weight tolerances for an order of pistons. | 5th Nov 1934 | Box 86 \ 2 scan0286 | |
| Letter from The Light Production Co. Ltd. regarding the supply and bedding of pistons machined to drawing E.84546. | 5th Nov 1934 | Box 86 \ 2 scan0287 | |
| Letter to The Light Production Co. Ltd. regarding the despatch of two replacement pistons. | 7th Nov 1934 | Box 86 \ 2 scan0288 | |
| Letter concerning overweight pistons, specifying a weight limit, and requesting a first production set for an experimental engine test. | 7th Nov 1934 | Box 86 \ 2 scan0289 | |
| Return of six Aerolite Pistons to the Light Production Co. for investigation and replacement. | 7th Nov 1934 | Box 86 \ 2 scan0290 | |
| Two Spectre Pistons sent to The Light Production Co. Ltd. for examination. | 8th Nov 1934 | Box 86 \ 2 scan0291 | |
| Use of semi-split and solid skirt pistons for the Spectre engine. | 8th Nov 1934 | Box 86 \ 2 scan0292 | |
| Letter to The Light Production Co. Ltd. regarding the weight of Aerolite pistons in different alloys. | 9th Nov 1934 | Box 86 \ 2 scan0293 | |
| Seized anodised pistons in a B-6 unit and a proposal to modify the cylinder block to continue testing. | 12th Nov 1934 | Box 86 \ 2 scan0294 | |
| Letter from The Light Production Co. Ltd. regarding the appearance of two run pistons, E.84546. | 12th Nov 1934 | Box 86 \ 2 scan0295 | |
| Letter from The Light Production Co. Ltd. regarding overweight pistons and the creation of a new metal corebox. | 12th Nov 1934 | Box 86 \ 2 scan0296 | |
| Letter to The Light Production Co. Ltd. concerning cylinder dimensions and experimental pistons. | 13th Nov 1934 | Box 86 \ 2 scan0297 | |
| Data sheet listing the diameters of new Aerolite pistons and cylinder bores. | 12th Nov 1934 | Box 86 \ 2 scan0298 | |
| Comparison of piston weights for 'Spectre' and 'Bentley' models. | 12th Nov 1934 | Box 86 \ 2 scan0299 | |
| Potential improvements to piston design, referencing American practice and the experience of the Aerolite Piston Co. | 22th Nov 1934 | Box 86 \ 2 scan0300 | |
| Piston design issues, cooling, and ring configurations for two-stroke and four-stroke engines. | 22th Nov 1934 | Box 86 \ 2 scan0301 | |
| Telegram requesting a spare piston from Aerolite Piston Co. to be sent by passenger train. | 24th Nov 1934 | Box 86 \ 2 scan0302 | |
| Letter confirming the dispatch of two spare pistons and requesting the return of a cracked piston for examination. | 26th Nov 1934 | Box 86 \ 2 scan0303 | |
| Advice note for the dispatch of two complete Aerolite Pistons with rings and pins. | 26th Nov 1934 | Box 86 \ 2 scan0304 | |
| Communication to Aerolite Piston Co. regarding the awaited arrival of RR-53 pistons. | 7th Dec 1934 | Box 86 \ 2 scan0305 | |
| Letter from The Light Production Co. Ltd. explaining delays in supplying Aerolite Pistons for the Bentley car due to new foundry equipment issues. | 7th Dec 1934 | Box 86 \ 2 scan0306 | |
| Letter from The Light Production Co. Ltd. regarding the dispatch and weight specifications of Bentley Aerolite Pistons. | 13th Dec 1934 | Box 86 \ 2 scan0307 | |
| Unsatisfactory thinness of anodic coating on pistons after testing. | 14th Dec 1934 | Box 86 \ 2 scan0308 | |
| Standardisation and testing of Aerolite Pistons for a B-6 engine. | 14th Dec 1934 | Box 86 \ 2 scan0309 | |
| Letter to The Light Production Co. Ltd. regarding the testing and agreed maximum weight of pistons. | 18th Dec 1934 | Box 86 \ 2 scan0310 | |
| On the weight of the first test set of Aerolite pistons for the R.R.53. | 18th Dec 1934 | Box 86 \ 2 scan0311 | |
| Dimensions and performance of a 25 HP exhaust system, particularly regarding silence and efficiency. | 1st Dec 1932 | Box 86 \ 3 scan0001 | |
| Drawing LeC.3379 for the Bensport Engine, detailing crankcase features for use on 20/25 HP production models. | 16th Feb 1933 | Box 86 \ 3 scan0002 | |
| Alternative design for a rear silencer exhaust tail pipe for the Bensport Series 1. | 20th Mar 1933 | Box 86 \ 3 scan0003 | |
| Drawings for an exhaust cutout, operating mechanism, and floorboards for the Bensport Series 1. | 6th Apr 1933 | Box 86 \ 3 scan0004 | |
| The trial of a Bensport Exhaust System on car No.3. | 13th Apr 1933 | Box 86 \ 3 scan0005 | |
| Work on a rubber suspension for two Bensport silencers, listing part numbers. | 29th Apr 1933 | Box 86 \ 3 scan0006 | |
| Bensport Exhaust System, detailing the rubber suspension for the tail pipe and axle rebound limitations. | 4th May 1933 | Box 86 \ 3 scan0007 | |
| Instruction to trial a rubber suspension for the Bensport exhaust system on all experimental Bentley cars. | 11th May 1933 | Box 86 \ 3 scan0008 | |
| Modifications to the Bensport Exhaust Cutout. | 17th May 1933 | Box 86 \ 3 scan0009 | |
| Specifications for the Bensport exhaust system for the first fifteen Bentley cars. | 23th May 1933 | Box 86 \ 3 scan0010 | |
| Modifications to the Bentley exhaust system, including drawing numbers and a change from oval to circular pipes. | 13th Jun 1933 | Box 86 \ 3 scan0011 | |
| Design of the Bentley exhaust system, specifically the tail pipe routing over the rear axle. | 15th Jun 1933 | Box 86 \ 3 scan0012 | |
| With a sketch detailing the modification of a Bentley exhaust cutout. | 16th Jun 1933 | Box 86 \ 3 scan0013 | |
| Efforts to reduce exhaust noise on a Bentley by rerouting the pipes. | 22th Jun 1933 | Box 86 \ 3 scan0014 | |
| Potential changes to the Bentley exhaust pipe design, advising against a 'swan neck' pipe. | 22th Jun 1933 | Box 86 \ 3 scan0015 | |
| Using a Silver Ghost cutout box and valve for the Bentley exhaust system to improve the sound. | 23th Jun 1933 | Box 86 \ 3 scan0016 | |
| Difficulty of routing a Bentley exhaust pipe over the rear axle and proposing an alternative. | 27th Jun 1933 | Box 86 \ 3 scan0017 | |
| Experimental scheme for a new exhaust system due to failure and corrosion on a previous version. | 24th Jul 1933 | Box 86 \ 3 scan0018 | |
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