| Description | Date | Identifier | |
| Steering column movement issues, wobble problems, and a comparison with a Bentley vehicle's steering system. | 28th Jun 1928 | Box 21 \ 2 Scan057 | |
| Performance evaluation of a car's key mechanical components. | 28th Jun 1928 | Box 21 \ 2 Scan058 | |
| Performance review and conclusion comparing a Bentley with a Phantom and a Chrysler. | 29th Jun 1928 | Box 21 \ 2 Scan059 | |
| Test drive and comparison of a Bentley Six-cylinder Saloon, noting steering and engine characteristics. | 29th Jun 1928 | Box 21 \ 2 Scan060 | |
| Report page comparing car steering selectivity and the prevention of steering wobbles. | 29th Jun 1928 | Box 21 \ 2 Scan061 | |
| Test report on a 4.5 Litre Bentley, detailing its performance and handling. | 12th Jul 1928 | Box 21 \ 2 Scan062 | |
| Road test report on a sports car, evaluating its suspension, braking, and transmission performance. | 12th Jul 1928 | Box 21 \ 2 Scan063 | |
| Road test and impressions of the 6 1/2 litre 6-cylinder Speed Model Bentley. | 26th Mar 1929 | Box 21 \ 2 Scan064 | |
| Secret internal memo discussing faults found in a Bentley and a proposed solution for engine roughness. | 10th Jul 1929 | Box 21 \ 2 Scan065 | |
| Letter from Mr W.E. Rootes to Mr H. Heath requesting dimensions for the 6 1/2 Litre Bentley engine. | 18th Jul 1929 | Box 21 \ 2 Scan066 | |
| And comparing engine measurements for various Bentley models. | 1st Aug 1929 | Box 21 \ 2 Scan067 | |
| Test drive report and impressions of a 6.5 litre Speed Bentley. | 22th Mar 1929 | Box 21 \ 2 Scan068 | |
| Page 2 of a typed report discussing a car's performance and body design. | 7th Aug 1929 | Box 21 \ 2 Scan069 | |
| Cover letter to Mr. Robotham enclosing copies of correspondence as requested. | 7th Aug 1929 | Box 21 \ 2 Scan070 | |
| Cover note attaching a report concerning the 8-Litre Bentley. | 17th Nov 1930 | Box 21 \ 2 Scan071 | |
| Test drive and assessment of a new 8-litre Bentley, comparing it to the Phantom II. | 14th Nov 1930 | Box 21 \ 2 Scan072 | |
| Conversation with the Maharajah of Rewa comparing the 8-litre Bentley to the Phantom II. | 12th Jan 1931 | Box 21 \ 2 Scan073 | |
| Filing instruction note for documents related to the 8 Litre Bentley. | 22th Jan 1931 | Box 21 \ 2 Scan074 | |
| Competitive threat of the 8 litre Bentley to the Phantom II, proposing to acquire one for analysis. | 22th Jan 1931 | Box 21 \ 2 Scan075 | |
| Power readings for a standard 8-litre engine Y.X.5106 with a 5.1 compression ratio. | 22th Jan 1931 | Box 21 \ 2 Scan076 | |
| Valve timing and clearances specifications for a 6-cylinder engine camshaft. | 27th Feb 1930 | Box 21 \ 2 Scan077 | |
| Technical notes on 8-litre engine valve and camshaft specifications. | 1st Dec 1949 | Box 21 \ 2 Scan078 | |
| Letter from Bentley Motors to Ernest Hives of Rolls Royce regarding an upcoming visit and car availability. | 27th Jan 1931 | Box 21 \ 2 Scan079 | |
| Letter to Col. Barrington of Bentley Motors arranging a meeting to demonstrate a new Continental Touring car. | 28th Jan 1930 | Box 21 \ 2 Scan080 | |
| Intelligence on a new competitor model from Bentley. | 3rd Feb 1931 | Box 21 \ 2 Scan081 | |
| The engine, performance, and handling characteristics of an 8 Litre Bentley. | 2nd Mar 1931 | Box 21 \ 2 Scan082 | |
| Short note describing rear hydraulic dampers and anchorage points. | 19th Mar 1931 | Box 21 \ 2 Scan083 | |
| Specifications of a new Bentley six-cylinder engine with a Ricardo patent head. | 19th Mar 1931 | Box 21 \ 2 Scan084 | |
| Blueprint diagram of a Ricardo Patent cylinder head. | 19th Mar 1931 | Box 21 \ 2 Scan085 | |
| Research into the 'booming' noise of car bodies, comparing their performance to Bentley products. | 7th Mar 1931 | Box 21 \ 2 Scan086 | |
| Arranging the use of Jack Barclay's 8-litre Bentley for tests of 26-EX at Brooklands. | 8th Apr 1931 | Box 21 \ 2 Scan087 | |
| Comparative performance tests between two Continental models and two Bentley cars. | 17th Apr 1931 | Box 21 \ 2 Scan088 | |
| Comparative test report on the performance of Bentley models, focusing on speed, acceleration, and engine characteristics. | 21th Apr 1931 | Box 21 \ 2 Scan089 | |
| Comparison of engine performance between Rolls-Royce and Bentley, with suggestions for improvements. | 21th Apr 1931 | Box 21 \ 2 Scan090 | |
| Engine performance, speed limitations, and the merits of a supercharged 12-cylinder engine. | 21th Apr 1931 | Box 21 \ 2 Scan091 | |
| Requesting to borrow a Bentley car with an enclosed body for an extended period of three to four weeks. | 25th Nov 1931 | Box 21 \ 2 Scan092 | |
| Arrangements to borrow a 4.5 Litre Supercharged and an 8 Litre Bentley car for examination. | 30th Nov 1931 | Box 21 \ 2 Scan093 | |
| The loan of an 8-litre Bentley for a week, clarifying whether a chassis or a complete car is required. | 24th Nov 1931 | Box 21 \ 2 Scan094 | |
| From 'E' arguing that the 8 Litre Bentley's running smoothness is comparable to their own cars. | 11th May 1931 | Box 21 \ 2 Scan095 | |
| Expressing relief that the new Bentley 4 Litre is not considered a severe competitor to the 20/25 model. | 29th May 1931 | Box 21 \ 2 Scan096 | |
| Expressing concerns about the design and potential issues of the Bentley 4 Litre. | 27th May 1931 | Box 21 \ 2 Scan097 | |
| Proposal for a new Bentley sports car model, detailing engine modifications and market positioning. | 5th Dec 1931 | Box 21 \ 2 Scan098 | |
| Internal discussion on future car development strategy, timelines, risks, and market positioning of new models. | 5th Dec 1931 | Box 21 \ 2 Scan099 | |
| Proposal outlining cost reductions for the production of a Bentley car. | 5th Dec 1931 | Box 21 \ 2 Scan100 | |
| Competitor sports cars 'Invicta' and 'Lagonda' in relation to the Bentley sports car market. | 7th Dec 1931 | Box 21 \ 2 Scan101 | |
| Noting the pre-existing poor condition of a Bentley 8-Litre car before testing. | 1st Jan 1932 | Box 21 \ 2 Scan102 | |
| Bentley 8-Litre car, noting its high mileage, noisy back axle, and bad piston knocks before testing. | 1st Jan 1932 | Box 21 \ 2 Scan103 | |
| Condition of a Bentley 8 Litre car after 18,000 miles and outlining future work. | 1st Jan 1932 | Box 21 \ 2 Scan104 | |
| Confirming an extension for a loaned 8-litre Bentley car from Jack Barclay Ltd. | 7th Jan 1932 | Box 21 \ 2 Scan105 | |
| Transport of a 4-Litre Bentley Engine and a spare camshaft to Derby. | 15th Jan 1932 | Box 21 \ 2 Scan106 | |
| Completion of a 4-litre engine for experimental work, including parts and costs. | 14th Jan 1932 | Box 21 \ 2 Scan107 | |
| Arrangements to transport a 4 Litre Bentley engine with its test stand and spare camshafts to Derby. | 16th Jan 1932 | Box 21 \ 2 Scan108 | |
| Experiments on crankshaft torsional vibration periods for an 8 Litre Bentley. | 12th Jan 1932 | Box 21 \ 2 Scan109 | |
| Crankshaft vibration periods and a proposed damper design, referencing the Bentley 8. | 19th Jan 1932 | Box 21 \ 2 Scan110 | |
| Requesting an update on the testing of a 4-litre engine purchased from the old Bentley company. | 26th Sep 1932 | Box 21 \ 2 Scan111 | |
| Crankshaft vibration periods, comparing their design to Bentley's and noting weaknesses in the latter's approach. | 21th Jan 1932 | Box 21 \ 2 Scan112 | |
| Status and future of a test 'Bentley' Four Litre Engine. | 27th Sep 1932 | Box 21 \ 2 Scan113 | |
| Bentley 4-Litre engine, discussing its saleability and potential return for spares. | 28th Sep 1932 | Box 21 \ 2 Scan114 | |
| The disposal of a 4 Litre Bentley test bed engine. | 13th Jan 1933 | Box 21 \ 2 Scan115 | |
| The return of a 4-Litre Bentley Engine. | 16th Jan 1933 | Box 21 \ 2 Scan116 | |
| Requesting transport arrangements for a 4-litre Bentley engine unit to be returned to the London Service Station. | 8th Feb 1933 | Box 21 \ 2 Scan117 | |
| Letter from Bentley Motors to Rolls-Royce concerning the specifications and forwarding of an 8-litre engine piston, gudgeon pin, and buttons. | 3rd Mar 1933 | Box 21 \ 2 Scan118 | |
| Service department letter detailing issues and procedures for cylinder wall wear and pin end button fitting. | 3rd Mar 1933 | Box 21 \ 2 Scan119 | |
| From EH to R detailing a test run of a Calcott car and its associated issues. | 30th Oct 1917 | Box 21 \ 3 Scan001 | |
| Calcott rim varnish and security bolts. | 8th Dec 1917 | Box 21 \ 3 Scan002 | |
| Confirming the despatch of parts to West Wittering for a Calcutt Car. | 31th Dec 1917 | Box 21 \ 3 Scan003 | |
| Receipt of a tin of paint and security bolts from The Dunlop Rubber Co. for Mr. Royce. | 31th Dec 1917 | Box 21 \ 3 Scan004 | |
| Incorrectly sized valve tubes for a Calcott car, noting the difference in diameter. | 20th Sep 1918 | Box 21 \ 3 Scan005 | |
| The return and replacement of tubes with unsuitable valves for Calcott Tyres. | 3rd Oct 1918 | Box 21 \ 3 Scan006 | |
| Failed Stewart speedometer from a Calcott car and instructions for its replacement. | 7th Oct 1918 | Box 21 \ 3 Scan007 | |
| Request for an aero engine primer and parts to be fitted to a Calthorpe car for trial purposes. | 10th Oct 1918 | Box 21 \ 3 Scan008 | |
| Confirming the dispatch of a Primer and pipe connection for the Calcott. | 9th Oct 1918 | Box 21 \ 3 Scan009 | |
| Cover letter regarding forwarding a letter anonymously on behalf of Mr. Royce to Calcott Bros., and a request for a tyre cover. | 26th Oct 1918 | Box 21 \ 3 Scan010 | |
| Letter to Calcott Bros. Ltd. regarding incorrectly sized brake straps and a request for replacements with specific dimensions. | 30th Oct 1925 | Box 21 \ 3 Scan011 | |
| Letter discussing the greasing of ball bearings, supply of castings for brake linings, and brake shoe springs. | 31th Oct 1918 | Box 21 \ 3 Scan012 | |
| The missing drive portion of a Stewart Speedometer. | 31th Oct 1918 | Box 21 \ 3 Scan013 | |
| Lost parcel containing worn out Stewart Speedometer parts for Mr. Royce's Calcott car. | 6th Nov 1918 | Box 21 \ 3 Scan014 | |
| Lost Stewart Speedometer parts for a Calcott model, including sketches for identification. | 6th Nov 1918 | Box 21 \ 3 Scan015 | |
| Letter from supplier Calcott Bros. Ltd. responding to a query about brakes, suggesting worn drums or oil leakage. | 7th Nov 1918 | Box 21 \ 3 Scan016 | |
| To Mr. Hives regarding communications with Calcott Bros Ltd. concerning the Calcott Car and a motor cover. | 8th Nov 1918 | Box 21 \ 3 Scan017 | |
| Cover note forwarding a letter from Calcott Bros. Ltd. and requesting instructions on the matter. | 11th Nov 1918 | Box 21 \ 3 Scan018 | |
| Request for spare parts for a Stewart Speedometer on a Calcott car. | 13th Nov 1918 | Box 21 \ 3 Scan019 | |
| Letter from Cooper Stewart Engineering Co. Ltd. providing a price for speedometer fittings. | 20th Nov 1918 | Box 21 \ 3 Scan020 | |
| Requesting particulars to obtain parts for a Calcott Speedometer. | 2nd Dec 1918 | Box 21 \ 3 Scan021 | |
| Particulars for speedometer parts for a 'Calcott' car. | 11th Dec 1918 | Box 21 \ 3 Scan022 | |
| Particulars to obtain speedometer parts for Mr. Royce's Calcott car. | 18th Dec 1918 | Box 21 \ 3 Scan023 | |
| Specifications for speedometer parts for a 'Calcutt' car. | 11th Dec 1918 | Box 21 \ 3 Scan024 | |
| Dispatch note confirming the sending of speedometer parts for a Calcott Car. | 27th Jan 1919 | Box 21 \ 3 Scan025 | |
| Request to obtain a spare Calcott clutch cone and two fibre wearing pieces for a clutch withdrawing fork. | 24th Mar 1919 | Box 21 \ 3 Scan026 | |
| Requesting the maker's number or build date for a 'Calcott' chassis to obtain spares. | 26th Mar 1919 | Box 21 \ 3 Scan027 | |
| The procurement of spares for a 'Calcott' car built in 1913/14. | 26th Mar 1919 | Box 21 \ 3 Scan028 | |
| Request to manufacture two brass acetylene lamp nipples for a Calcott car, to be charged to Mr. Royce's private account. | 27th Mar 1919 | Box 21 \ 3 Scan029 | |
| Inability to find an identification number on a 1914 Calcott car for clutch spares. | 29th Mar 1919 | Box 21 \ 3 Scan030 | |
| Replacement of an aluminium leather-lined clutch with a malleable cone clutch lined with Thermoid. | 2nd Apr 1919 | Box 21 \ 3 Scan031 | |
| Proposing a modification to the 'Calcett' car clutch withdrawing mechanism with a diagram for new washers. | 4th Apr 1919 | Box 21 \ 3 Scan032 | |
| Confirming the dispatch of two washers for a Calcott Car. | 7th Apr 1919 | Box 21 \ 3 Scan033 | |
| Need for radiator louvres to improve engine performance with poor quality petrol. | 9th Apr 1919 | Box 21 \ 3 Scan034 | |
| Engine performance using benzol fuel from Birchenwood Collieries, noting issues with over-richness at slow speeds. | 9th Apr 1919 | Box 21 \ 3 Scan035 | |
| Requesting a Buick car with specific instructions regarding the condition of its tyres and rims. | 20th May 1919 | Box 21 \ 3 Scan036 | |
| The delivery of a Cadillac, a Marmon car, and the logistics of temporarily sending an experimental car to the USA. | 29th Sep 1920 | Box 21 \ 3 Scan037 | |
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