| Description | Date | Identifier | |
| Potential causes and solutions for magneto drive slip and camshaft drive failure. | 16th Oct 1926 | Box 65 \ 4 scan0246 | |
| The results of a test on Chassis No. 7-LF to address a 'galloping knock'. | 13th Jan 1928 | Box 65 \ 4 scan0247 | |
| Page two of a memo discussing the results of a new material for slipper drives and the need for further testing. | 16th Jan 1933 | Box 65 \ 4 scan0248 | |
| Experimental slipper flywheel settings for the 7-LF car, comparing them to Springfield and Phantom standards. | 16th Jan 1933 | Box 65 \ 4 scan0249 | |
| Investigating an engine knock in a 7-LP car by adjusting the slipper wheel. | 5th Jan 1928 | Box 65 \ 4 scan0250 | |
| Request to put in hand one set of heavier-than-standard slipper flywheels for a Phantom model. | 19th Jan 1928 | Box 65 \ 4 scan0251 | |
| Modification to the Phantom Spring Drive, referencing manufacturing orders. | 23th Jan 1928 | Box 65 \ 4 scan0252 | |
| Requesting an urgent order of flywheel springs for a Phantom spring drive to test a fix for 'galloping knocks'. | 20th Jan 1928 | Box 65 \ 4 scan0253 | |
| Investigation into the cause of a 'galloping knock' engine noise reported by customers. | 23th Jan 1928 | Box 65 \ 4 scan0254 | |
| Investigation into engine knock, involving tests with a slipper wheel and analysis of crankshaft torsional stress. | 23th Jan 1928 | Box 65 \ 4 scan0255 | |
| Analysis of crankshaft torsional strain and engine knock caused by slipper wheel friction. | 5th Jun 1928 | Box 65 \ 4 scan0256 | |
| Design and testing of a stronger driving spring (E.77646) for a Phantom model. | 5th Jun 1928 | Box 65 \ 4 scan0257 | |
| The replacement of a damper spring for the crankshaft spring drive on a Phantom car. | 13th Aug 1928 | Box 65 \ 4 scan0258 | |
| Suitability and modification of a crankshaft spring drive for a Phantom car's camshaft. | 14th Aug 1928 | Box 65 \ 4 scan0259 | |
| Order for 8 springs with specific dimensions and material. | 1st Oct 1928 | Box 65 \ 4 scan0260 | |
| Engine alterations involving longer connecting rods and shorter pistons. | 3rd Jun 1924 | Box 65 \ 4 scan0261 | |
| Performance of longer connecting rods and lighter pistons in the 46-PK engine. | 12th Jul 1924 | Box 65 \ 4 scan0262 | |
| Secret memo discussing modifications to pistons, connecting rods, exhaust pipes, and the Scintilla magneto. | 17th Jul 1924 | Box 65 \ 4 scan0263 | |
| Cable regarding the use of copper tubes in the cylinder and head for the E.A.C. engine. | 16th Mar 1925 | Box 65 \ 4 scan0264 | |
| Connecting rod bearing failure on a car during tests in France. | 16th Apr 1925 | Box 65 \ 4 scan0265 | |
| The condition of connecting rod bearings after a 10,000-mile test in France. | 18th Apr 1925 | Box 65 \ 4 scan0266 | |
| Test to reproduce connecting rod bearing failure on an EAC engine. | 25th Sep 1924 | Box 65 \ 4 scan0267 | |
| Telegram reporting the failure of conrod big ends and requesting two new high-speed rods to continue testing. | 9th May 1925 | Box 65 \ 4 scan0268 | |
| Form for a telegram received by telephone with handwritten notes. | 23th May 1923 | Box 65 \ 4 scan0269 | |
| The failure of connecting rod bearings on a 93-NK car. | 12th May 1925 | Box 65 \ 4 scan0270 | |
| Despatch of 6 connecting rods to Mr. Royce. | 1st Jun 1925 | Box 65 \ 4 scan0271 | |
| The failure of connecting rods from a 93-NK car, noting issues with whitemetal adhesion. | 1st Jun 1925 | Box 65 \ 4 scan0272 | |
| Confirmation of a wire message regarding an investigation into different alloy steels for connecting rods. | 6th Jun 1925 | Box 65 \ 4 scan0273 | |
| Modifications and trials for connecting rods. | 12th Jun 1925 | Box 65 \ 4 scan0274 | |
| Three proposed experiments for modifying EAC connecting rods. | 12th Jun 1925 | Box 65 \ 4 scan0275 | |
| Proposing the use of duralumin connecting rods in the EAC engine to reduce weight and vibrations. | 1st Jul 1925 | Box 65 \ 4 scan0276 | |
| Modifications to New Phantom connecting rods and camshaft bearings. | 25th Aug 1925 | Box 65 \ 4 scan0277 | |
| Endurance test of various connecting rod bearings. | 16th Sep 1925 | Box 65 \ 4 scan0278 | |
| Tests of connecting rod big end bearings, comparing standard and mild steel rods. | 28th Sep 1925 | Box 65 \ 4 scan0279 | |
| 22.5 hour test of new E.A.C. connecting rod bearings with loose white metal lined bushes. | 28th Sep 1925 | Box 65 \ 4 scan0280 | |
| Crankcase expansion, bearing thrust, and comparing the reliability of bronze versus mild steel loose bushes. | 28th Sep 1925 | Box 65 \ 4 scan0281 | |
| Table detailing design changes and specifications for New Phantom model connecting rods. | 24th Jun 1925 | Box 65 \ 4 scan0282 | |
| Cablegram from Springfield to Derby requesting details for a Phantom connecting rod with separate big end bushing. | 2nd Dec 1925 | Box 65 \ 4 scan0283 | |
| Standardisation document for modified connecting rod bearings. | 10th Dec 1925 | Box 65 \ 4 scan0284 | |
| Design change for the 20 HP chassis connecting rods to use separate bushes, similar to the Phantom model. | 7th Jan 1926 | Box 65 \ 4 scan0285 | |
| Test on a lighter Phantom engine using old short rods to save weight and reduce crankcase height. | 23th Feb 1926 | Box 65 \ 4 scan0286 | |
| Modifications to the Lighter Phantom Engine's connecting rod length. | 15th Apr 1926 | Box 65 \ 4 scan0287 | |
| Choice between long or short connecting rods for the Lighter Phantom Engine. | 19th Apr 1926 | Box 65 \ 4 scan0288 | |
| Modifications and testing for a lighter Phantom engine, focusing on weight reduction. | 4th May 1926 | Box 65 \ 4 scan0289 | |
| Defect in Phantom cylinder block castings and proposed remedies to eliminate piston knocks. | 25th Jun 1927 | Box 65 \ 4 scan0290 | |
| Modifications and casting improvements for Phantom cylinder blocks. | 27th Jun 1927 | Box 65 \ 4 scan0291 | |
| Disagreeing with the suggestion to ask customers to tighten the cylinder head and adjust tappets post-repair. | 4th Jul 1927 | Box 65 \ 4 scan0292 | |
| Proposal to experiment with fitting Hispano connecting rods to the Phantom engine to improve smoothness. | 9th Sep 1927 | Box 65 \ 4 scan0293 | |
| Confirming the sending of drawing LeC. 2466 for the Phantom Sports Connecting Rod. | 1st Oct 1927 | Box 65 \ 4 scan0294 | |
| Proposed tubular type connecting rod for the Sports Phantom. | 4th Oct 1927 | Box 65 \ 4 scan0295 | |
| Phone message confirmation regarding alterations to a sports car due to a broken crankchamber. | 8th Oct 1927 | Box 65 \ 4 scan0296 | |
| Comparing the weights of tubular section connecting rods between various cars. | 18th Oct 1927 | Box 65 \ 4 scan0297 | |
| Comparison table of engine component specifications for 20HP, 40/50HP, Lorraine, and Hispano engines. | 25th Nov 1927 | Box 65 \ 4 scan0298 | |
| Revisions to the crankshaft and connecting rods for EAC.10 and 14 models. | 25th Nov 1927 | Box 65 \ 4 scan0299 | |
| Comparison of Pierce Arrow and Phantom connecting rod piston assembly weights, with a request to source Pierce Arrow parts for inspection. | 2nd Jan 1928 | Box 65 \ 4 scan0300 | |
| Proposed alterations to the 'V' series exhaust pipes, main switch, and thermometer position. | 8th Dec 1924 | Box 65 \ 4 scan0301 | |
| Material change for valve stem guides in the E.A.C.II cylinder head from Cast Iron to Phosphor Bronze. | 2nd Dec 1924 | Box 65 \ 4 scan0302 | |
| Material choice between Stainless Steel and Monel Metal for E.A.C. cylinder tubes. | 23th Jan 1925 | Box 65 \ 4 scan0303 | |
| Difficulties in swaging stainless steel and Monel metal cylinder water tubes, with a comparison to copper and thermal expansion data. | 26th Jan 1925 | Box 65 \ 4 scan0304 | |
| The causes of 'EAC' over-oiling, focusing on oil passing valve stems and the optimal orientation of scraper rings. | 2nd Feb 1925 | Box 65 \ 4 scan0305 | |
| Cylinder over-oiling, offering a theory on the performance of chamfered piston rings. | 25th Sep 1924 | Box 65 \ 4 scan0306 | |
| Choice of material for cylinder water tubes, comparing copper, monel metal, and stainless steel. | 9th Mar 1925 | Box 65 \ 4 scan0307 | |
| Tubes in cylinder heads, comparing monel, copper, and stainless steel, and recommending copper for future use. | 11th Mar 1925 | Box 65 \ 4 scan0308 | |
| Reliability and expansion of copper tubes in cylinder heads. | 23th Mar 1925 | Box 65 \ 4 scan0309 | |
| Calculated versus tested cylinder capacity, and the instructed acceptable range. | 27th Mar 1925 | Box 65 \ 4 scan0310 | |
| Cylinder temperature, expansion, and oiling for the EAC engine. | 16th May 1925 | Box 65 \ 4 scan0311 | |
| Tests with a new cylinder head and new sparking plug positions. | 18th Sep 1925 | Box 65 \ 4 scan0312 | |
| EAC engine with opposed sparking plugs and an induction pipe in the cylinder head. | 18th Sep 1925 | Box 65 \ 4 scan0313 | |
| Engine power loss, distribution, and detonation under different induction and ignition configurations. | 18th Sep 1925 | Box 65 \ 4 scan0314 | |
| Investigating the influence of spark plug position and ignition timing on engine detonation and power. | 18th Sep 1925 | Box 65 \ 4 scan0315 | |
| The effect of single and dual ignition systems on ignition advance and detonation. | 18th Sep 1925 | Box 65 \ 4 scan0316 | |
| Performance graph showing engine Brake Horsepower against RPM to illustrate power loss caused by a water-heated induction pipe. | 20th Jul 1925 | Box 65 \ 4 scan0317 | |
| Performance graph comparing induction systems by plotting Brake Horsepower against Revolutions Per Minute. | 23th Jul 1925 | Box 65 \ 4 scan0318 | |
| Graph plotting ignition firing position against engine RPM to determine the optimal advance for maximum torque and to avoid detonation. | 18th Aug 1925 | Box 65 \ 4 scan0319 | |
| Graph plotting firing position against RPM for a single cylinder engine with a 5.2 to 1 compression ratio. | 10th Nov 1925 | Box 65 \ 4 scan0320 | |
| Weights of the EAC cylinder block and cylinder head. | 10th Nov 1925 | Box 65 \ 4 scan0321 | |
| Error in a design report and the design of an aluminium head and cylinders for the Phantom. | 1st Dec 1925 | Box 65 \ 4 scan0322 | |
| Outlining the benefits of using an aluminium head and cylinders for the Phantom engine. | 8th Feb 1926 | Box 65 \ 4 scan0323 | |
| Further testing on a Phantom cylinder head with opposed sparking plugs to investigate detonation and silencer popping. | 2nd Feb 1926 | Box 65 \ 4 scan0324 | |
| Revised proposals for a lighter Phantom engine with an aluminum cylinder head and block. | 27th Feb 1926 | Box 65 \ 4 scan0325 | |
| Technical memo discussing design suggestions for the Phantom cylinder head to improve combustion and spark plug placement. | 6th Mar 1926 | Box 65 \ 4 scan0326 | |
| Analysis of turbulence in combustion, referencing various engine designs including those by Ricardo, Duesenberg, and Hispano. | 6th Mar 1926 | Box 65 \ 4 scan0327 | |
| Engine cam and cylinder head design, comparing different methods for achieving turbulence and efficiency. | 10th Mar 1926 | Box 65 \ 4 scan0328 | |
| Drawing LeC.2212 for the Phantom Aluminium Head and discussing modifications requested by Mr. Royce. | 10th Mar 1926 | Box 65 \ 4 scan0329 | |
| Simplification of the induction pipe bolting for a Phantom Aluminium Head. | 10th Mar 1926 | Box 65 \ 4 scan0330 | |
| Recommendation to modify Phantom cylinders with extra thickness to reduce knocking sounds. | 1st Mar 1926 | Box 65 \ 4 scan0331 | |
| Issue of 'No.5. Cylinder Knock' and the proposed solution of standardizing cylinders with extra thickness on the trunks. | 19th Mar 1926 | Box 65 \ 4 scan0332 | |
| Design schemes and weight-saving suggestions for the Lighter Phantom Engine. | 31th Mar 1926 | Box 65 \ 4 scan0333 | |
| Use of a larger diameter duralumin valve push rod for the lighter Phantom engine. | 23th Apr 1926 | Box 65 \ 4 scan0334 | |
| Modifications and tests for a lighter Phantom engine, focusing on weight reduction and a new anti-detonating head. | 4th May 1926 | Box 65 \ 4 scan0335 | |
| Investigation into 'engine thuds' on the Phantom engine compared to the Silver Ghost. | 1st May 1926 | Box 65 \ 4 scan0336 | |
| The occurrence of engine thuds, requesting an example be set aside for experimental study. | 17th May 1926 | Box 65 \ 4 scan0337 | |
| Definition and cause of 'engine thuds' in various car models, particularly the Phantom and Silver Ghost. | 19th May 1926 | Box 65 \ 4 scan0338 | |
| Characteristics and naming of an engine thud, suggesting it be called a throb or 'the Gilpin' trouble. | 21th May 1926 | Box 65 \ 4 scan0339 | |
| Engine thuds and a throbbing sensation in vehicle 87-LC, while also arranging a visit to Derby. | 22th May 1926 | Box 65 \ 4 scan0340 | |
| Design changes to the Phantom Aluminium Cylinder Block, including increasing its height. | 7th Jun 1926 | Box 65 \ 4 scan0341 | |
| Instruction memo detailing the testing process for new copper asbestos cylinder gaskets for the New Phantom engine. | 28th Jun 1926 | Box 65 \ 4 scan0342 | |
| Procedure for fitting and testing new Phantom cylinder gaskets. | 29th Jun 1926 | Box 65 \ 4 scan0343 | |
| Modifications to the cylinder head water outlet for the Lighter Phantom Engine. | 6th Jul 1926 | Box 65 \ 4 scan0344 | |
| Design alternatives for a lighter valve rocker cover for the Phantom engine, comparing a two-piece pressed and riveted design against a magnesium alloy casting. | 6th Jul 1926 | Box 65 \ 4 scan0345 | |
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