| Description | Date | Identifier | |
| Experimental department report on Phantom II self-adjusting tappets. | 25th Apr 1934 | Box 17 \ 6 Scan200 | |
| Promising new hydraulic tappet design and its proposed road testing. | 25th Apr 1934 | Box 17 \ 6 Scan201 | |
| Improvements for direct-acting, self-adjusting tappets to prevent air locking in the oil feed. | 25th Apr 1934 | Box 17 \ 6 Scan202 | |
| Comparison of two plunger mechanism schemes (Hs.1206 & Hs.1210) and test results for self-adjusting tappets. | 25th Apr 1934 | Box 17 \ 6 Scan203 | |
| The design and testing of engine tappets, discussing noise, clearances, and performance. | 25th Apr 1934 | Box 17 \ 6 Scan204 | |
| The continuous running test of self-adjusting tappets and comparison of different plunger types. | 25th Apr 1934 | Box 17 \ 6 Scan205 | |
| Blueprint for a self-adjusting tappet for Bentley and 25HP models. | 24th Apr 1934 | Box 17 \ 6 Scan206 | |
| Schematic diagram showing three different designs for self-adjusting tappets. | 24th Apr 1934 | Box 17 \ 6 Scan207 | |
| Letter to Major F.B. Halford regarding valve mechanism modifications, enclosing a blueprint for a Phantom II valve rocker. | 30th Apr 1934 | Box 17 \ 6 Scan208 | |
| Letter from Frank B. Halford suggesting academic papers related to valve spring breakages at low temperatures. | 30th Apr 1934 | Box 17 \ 6 Scan209 | |
| Letter to Major F.B. Halford acknowledging his correspondence of 30th April. | 1st May 1934 | Box 17 \ 6 Scan210 | |
| Request to set up a valve gear rig for investigating valve bounce on a Phantom engine. | 4th May 1934 | Box 17 \ 6 Scan211 | |
| Investigating complaints of sticking valves by comparing the valve mechanisms of Phantom, 20/25 HP, and Bentley cars. | 16th May 1934 | Box 17 \ 6 Scan212 | |
| Limits of reducing the exhaust valve size without a loss of power, referencing curve Hs.1214. | 19th May 1934 | Box 17 \ 6 Scan213 | |
| Letter from Cadillac regarding the status of a '16' project, a LaSalle nose, and technical details on valve springs and cams. | 9th May 1934 | Box 17 \ 6 Scan214 | |
| Page 2 of a letter from Special Problems Engineer Maurice Olley regarding an enquiry about a Captain E. J. Waters. | 16th Jul 1931 | Box 17 \ 6 Scan215 | |
| Heat treatment specification document from Cadillac Motor Car Company for an unspecified part. | 16th Jul 1931 | Box 17 \ 6 Scan216 | |
| Heat treat specification from the Cadillac Motor Car Company, detailing physical properties, treatment processes, and general specifications for wire. | 16th Jul 1931 | Box 17 \ 6 Scan217 | |
| Chart of fatigue limits for valve spring wire, plotting final stress against initial stress. | 9th May 1934 | Box 17 \ 6 Scan218 | |
| Blank document page with a date stamp on the bottom left. | 9th May 1934 | Box 17 \ 6 Scan219 | |
| Material specification for Chrome Vanadium Steel Spring Wire. | 9th May 1934 | Box 17 \ 6 Scan220 | |
| Specification for soft Swedish steel valve spring wire. | 17th May 1934 | Box 17 \ 6 Scan221 | |
| Instructions for new exhaust valve components on a Phantom II chassis to prevent sticking. | 17th May 1934 | Box 17 \ 6 Scan222 | |
| Letter to George Salter & Co. Ltd. detailing the composition and heat treatment for two types of steel for valve springs. | 24th May 1934 | Box 17 \ 6 Scan223 | |
| Letter discussing the use of carbon steel versus chrome vanadium for springs of different sizes. | 24th May 1934 | Box 17 \ 6 Scan224 | |
| Letter from Geo. Salter & Co Ltd discussing two types of steel for valve springs. | 25th May 1934 | Box 17 \ 6 Scan225 | |
| Request for chromium plating of parts for a Valve Spring Rig, including a diagram. | 25th May 1934 | Box 17 \ 6 Scan226 | |
| Letter to Geo. Salter & Co. Ltd. regarding the disadvantages of No. 1 steel due to segregation. | 28th May 1934 | Box 17 \ 6 Scan227 | |
| Requesting an additional attachment, H.R. 87, for a Valve Spring Rig. | 28th May 1934 | Box 17 \ 6 Scan228 | |
| Request for a set of modified Phantom II Halford type self-adjusting tappets with specific modifications. | 29th May 1934 | Box 17 \ 6 Scan229 | |
| Modifications for a new set of Cadillac type automatic tappet mechanisms for Phantom II engines. | 29th May 1934 | Box 17 \ 6 Scan230 | |
| Request for the manufacture of a set of open-ended valve springs for Phantom II Unit No. 28. | 31th May 1934 | Box 17 \ 6 Scan231 | |
| Valve spring performance and requirements for use with Cadillac silent tappets. | 4th Jun 1934 | Box 17 \ 6 Scan232 | |
| Specifications for replacement taper valve springs for F.II Unit No. 28, cancelling a previous instruction. | 5th Jun 1934 | Box 17 \ 6 Scan233 | |
| Request to manufacture a set of modified inlet and exhaust valves with associated cotters and washers. | 9th Jun 1934 | Box 17 \ 6 Scan234 | |
| Valve springs for silent tappets on the Phantom model. | 13th Jun 1934 | Box 17 \ 6 Scan235 | |
| Experimental trial of Phantom valves, springs, and hydraulic silent tappets. | 13th Jun 1934 | Box 17 \ 6 Scan236 | |
| Details on using Cadillac-type automatic tappets and associated components for the Phantom II model. | 12th Jun 1934 | Box 17 \ 6 Scan237 | |
| Cadillac type automatic tappets for the Phantom II. | 15th Jun 1934 | Box 17 \ 6 Scan238 | |
| Tests on Cadillac type automatic tappets for the Phantom II to investigate high-speed valve float and power loss. | 15th Jun 1934 | Box 17 \ 6 Scan239 | |
| Summary of test results comparing different camshafts and the effects of various valve springs on engine performance. | 15th Jun 1934 | Box 17 \ 6 Scan240 | |
| Tests on camshafts and valve springs to resolve high-speed engine trouble. | 15th Jun 1934 | Box 17 \ 6 Scan241 | |
| Camshaft performance and the effect of stiffening the valve mechanism. | 15th Jun 1934 | Box 17 \ 6 Scan242 | |
| Graph comparing engine power curves for a Phantom II with an open exhaust and 5.25:1 compression ratio, testing two different camshaft and rocker setups. | 14th Jun 1934 | Box 17 \ 6 Scan243 | |
| Blank page with a Print Room stamp. | 18th Jun 1934 | Box 17 \ 6 Scan244 | |
| Graph showing the opening and closing contour of valve lift for Cadillac type tappets on a Phantom II camshaft. | 14th Jun 1934 | Box 17 \ 6 Scan245 | |
| Blank document stamped by the Print Room in Derby. | 18th Jun 1934 | Box 17 \ 6 Scan246 | |
| Letter from General Motors Corporation requesting design details for a ball type valve. | 11th Jun 1934 | Box 17 \ 6 Scan247 | |
| Letter to General Motors Corporation regarding a ball valve scheme for a silent tappet. | 19th Jun 1934 | Box 17 \ 6 Scan248 | |
| Requesting holes to be drilled in rockers for feeding oil to valve tips on automatic tappets for chassis 28-EX. | 20th Jun 1934 | Box 17 \ 6 Scan249 | |
| Standardisation of stepped exhaust valve stems. | 1st Jun 1934 | Box 17 \ 6 Scan250 | |
| Cost estimate and production note for extra jigs, tools, and equipment for the 'T' series chassis. | 28th May 1934 | Box 17 \ 6 Scan251 | |
| Requesting the preparation of stellited exhaust valves and seats for Phantom and Bentley engine tests. | 21th Jun 1934 | Box 17 \ 6 Scan252 | |
| Power curve showing the effects of silent tappets on the Phantom engine. | 21th Jun 1934 | Box 17 \ 6 Scan253 | |
| Graph comparing power (BHP) and Mean Effective Pressure (MEP) against engine speed (RPM) for a Phantom II engine with different tappet setups. | 21th Jun 1934 | Box 17 \ 6 Scan254 | |
| Stamped cover page from the Print Room. | 21th Jun 1934 | Box 17 \ 6 Scan255 | |
| The theoretical effects of Cadillac automatic tappets on valve bounce speed and spring load for the Ph.II unit. | 21th Jun 1934 | Box 17 \ 6 Scan256 | |
| Table and analysis of valve spring loads against critical speeds for valve bounce. | 21th Jun 1934 | Box 17 \ 6 Scan257 | |
| Effect of cam profiles on actual and theoretical valve bouncing speeds. | 21th Jun 1934 | Box 17 \ 6 Scan258 | |
| Analysis of deviations in standard camshaft profiles and their effect on exhaust valve lift and velocity. | 21th Jun 1934 | Box 17 \ 6 Scan259 | |
| Graph plotting the speed at which the No.6 exhaust valve rides against the valve spring load for PI Unit BJ55. | 21th Jun 1934 | Box 17 \ 6 Scan260 | |
| Specification sheet for Phantom II camshaft forms, detailing lift and deviations. | 21th Jun 1934 | Box 17 \ 6 Scan261 | |
| Velocity diagram for a No.6 exhaust cam, showing designed vs actual performance. | 21th Jun 1934 | Box 17 \ 6 Scan262 | |
| Letter to A.E.C. Co. Ltd. inquiring why they have abandoned the Cadillac silent tappet. | 28th Jun 1934 | Box 17 \ 6 Scan263 | |
| Letter from Associated Equipment Company regarding an investigation into the General Motors valve lash mechanism. | 30th Jun 1934 | Box 17 \ 6 Scan264 | |
| Letter from The Associated Equipment Co. Ltd. discussing the adoption of compression ignition oil engines. | 30th Jun 1934 | Box 17 \ 6 Scan265 | |
| Letter acknowledging information received on the Cadillac Silent Tappet and returning prints. | 3rd Jul 1934 | Box 17 \ 6 Scan266 | |
| Letter to C.J. Rackham of The Associated Equipment Co. Ltd. enclosing prints and a report that were previously omitted. | 5th Jul 1934 | Box 17 \ 6 Scan267 | |
| Urgent request for parts for a valve spring rig. | 5th Jul 1934 | Box 17 \ 6 Scan268 | |
| Letter from Wilcox-Rich Corporation detailing the improvements and advantages of their valve tappets. | 25th Jun 1934 | Box 17 \ 6 Scan269 | |
| From Wilcox-Rich Corporation comparing Rich Type, Cylindrical, and Hydraulic engine tappets. | 25th Jun 1934 | Box 17 \ 6 Scan270 | |
| Letter from Wilcox-Rich Corporation discussing engine components like hydraulic lifters, salt-cooled valves and valve seat inserts. | 25th Jun 1934 | Box 17 \ 6 Scan271 | |
| Micro-examination report comparing the surface finish and decarburisation of piano wire from three English manufacturers. | 5th Jul 1934 | Box 17 \ 6 Scan272 | |
| Report page detailing hardness tests (Brinell and Vickers) and slag inclusion analysis on wire samples. | 5th Jul 1934 | Box 17 \ 6 Scan273 | |
| Cover note to accompany Report M960. | 13th Apr 1934 | Box 17 \ 6 Scan274 | |
| Laboratory photomicrograph of 'Brunton's Jupiter' material at 10 diameters magnification. | 13th Apr 1934 | Box 17 \ 6 Scan275 | |
| Blank page with handwritten reference numbers at the top. | 13th Apr 1934 | Box 17 \ 6 Scan276 | |
| Photomicrograph comparing materials from 'Brunton's Jupiter' and 'Shipman's' at 150 diameters magnification. | 13th Apr 1934 | Box 17 \ 6 Scan277 | |
| Reference numbers on a blank document. | 6th Jul 1934 | Box 17 \ 6 Scan278 | |
| Letter from General Motors regarding the blueprint for a ball valve installation in a silent tappet. | 6th Jul 1934 | Box 17 \ 6 Scan279 | |
| Requesting an alteration to the rocker shaft diameter on drawing E.84407. | 11th Jul 1934 | Box 17 \ 6 Scan280 | |
| Testing instructions from the A.E.C. for G.M. Type Automatic Tappets. | 12th Jul 1934 | Box 17 \ 6 Scan281 | |
| Requesting the fitting of specific inlet and exhaust valves to a standard Phantom Cylinder Head. | 17th Jul 1934 | Box 17 \ 6 Scan282 | |
| Urgent request for the Millwrights Department to fit a pulley and belt to a Valve Spring Rig. | 13th Jul 1934 | Box 17 \ 6 Scan283 | |
| Instructions for modifications to self-adjusting tappets and rocker bushes for model 28-EX. | 18th Jul 1934 | Box 17 \ 6 Scan284 | |
| Blueprint drawing of a Moon Oil Metering Screw (Part II). | 18th Jul 1934 | Box 17 \ 6 Scan285 | |
| Drawing detailing modifications to a bush for rockers, specifically for auto tappets. | 18th Jul 1934 | Box 17 \ 6 Scan286 | |
| The unsuccessful trial of stiffer, double-taper push rods in a Phantom II valve gear. | 24th Jul 1934 | Box 17 \ 6 Scan287 | |
| Drawing for a new steel push rod for the Phantom II valve gear. | 20th Jul 1934 | Box 17 \ 6 Scan288 | |
| Mathematical analysis detailing the effect of leakage in hydraulic tappets. | 24th Jul 1934 | Box 17 \ 6 Scan289 | |
| Technical analysis and comparison of leakage effects in silent tappets for various engine models. | 24th Jul 1934 | Box 17 \ 6 Scan290 | |
| Valve spring load inconsistencies causing valve bounce speed issues in a Ph.II engine. | 24th Jul 1934 | Box 17 \ 6 Scan291 | |
| Request to machine plungers for self-adjusting tappets (28-EX), including a list of current dimensions and clearances. | 26th Jul 1934 | Box 17 \ 6 Scan292 | |
| Conclusions on car engine valve gear, including drilled valves, manufacturing improvements, and hydraulic tappet adjustments. | 27th Jul 1934 | Box 17 \ 6 Scan293 | |
| Valve gear design, comparing Cadillac and Halford schemes, and considering the number of valves per cylinder. | 27th Jul 1934 | Box 17 \ 6 Scan294 | |
| Single-cylinder unit modifications and valve mechanism deflection. | 27th Jul 1934 | Box 17 \ 6 Scan295 | |
| Technical note on the inconsistency and lack of reliable data regarding valve bounce in engines. | 18th Jul 1934 | Box 17 \ 6 Scan296 | |
| Comparison table of camshaft and valve performance data across various engine models. | 18th Jul 1934 | Box 17 \ 6 Scan297 | |
| Technical analysis of engine valve gear bounce speeds, with a table comparing theoretical speeds for various car models. | 18th Jul 1934 | Box 17 \ 6 Scan298 | |
| Tappet spring performance, valve bounce speeds, and a comparison of Halford and G.M. type automatic tappets. | 18th Jul 1934 | Box 17 \ 6 Scan299 | |
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