| Description | Date | Identifier | |
| Testing of malleable iron exhaust manifolds for a Phantom II to prevent fractures caused by thermal expansion. | 17th Apr 1931 | Box 14 \ 6 Scan193 | |
| Delay of improved exhaust manifolds for P. 1. & G. 1. models due to illness. | 23th Apr 1931 | Box 14 \ 6 Scan194 | |
| Comparison of engine capacity, downtake, and swanneck dimensions for the 40/50 and 20/25 models. | 6th May 1931 | Box 14 \ 6 Scan195 | |
| Standardization of extended exhaust tail pipes for P.2 & 25 HP models. | 2nd Jun 1931 | Box 14 \ 6 Scan196 | |
| Increased cost of a hinged support for exhaust tail pipes on Phantom II and 25 HP models. | 5th Jun 1931 | Box 14 \ 6 Scan197 | |
| Power loss in the Phantom II exhaust system and the need to reduce back pressure. | 13th Jun 1931 | Box 14 \ 6 Scan198 | |
| Graph of power tests on a PI Unit, comparing performance with an open exhaust against a standard silencer system. | 15th Jun 1931 | Box 14 \ 6 Scan199 | |
| Page marked with a receiving stamp from the H.T. Room in Derby. | 15th Jun 1931 | Box 14 \ 6 Scan200 | |
| From Sg. to Hs. regarding Hancock's report on valve clearance issues under hard usage. | 14th Jul 1931 | Box 14 \ 6 Scan201 | |
| Modifications to the P. 2. long duration camshaft to improve engine performance. | 21th Jul 1931 | Box 14 \ 6 Scan202 | |
| Experiments in France to fix exhaust valves losing clearances, suggesting salt-cooled valves from the 'R' engines as a solution. | 22th Jul 1931 | Box 14 \ 6 Scan203 | |
| Inquiring about the progress of an investigation into frequent complaints about the short life of exhaust silencers. | 6th Aug 1931 | Box 14 \ 6 Scan204 | |
| Design and material of exhaust valves for the P.2 model following a 10,000-mile test. | 13th Aug 1931 | Box 14 \ 6 Scan205 | |
| Suggestion to address power limitation on the Phantom II by trying cooler, possibly salt-cooled, valves. | 17th Aug 1931 | Box 14 \ 6 Scan206 | |
| Improved exhaust and inlet valves and the potential need for a longer duration cam due to their increased weight. | 1st Aug 1931 | Box 14 \ 6 Scan207 | |
| Standardisation of chassis parts, specifically for a lengthened rear exhaust pipe. | 27th Jun 1931 | Box 14 \ 6 Scan208 | |
| Replacement of Staybrite exhaust downtake pipes with fescolised steel pipes for Phantom II and 20/25 HP chassis. | 8th Oct 1931 | Box 14 \ 6 Scan209 | |
| The failure of experimental 'fescalised' mild steel exhaust pipes during testing. | 9th Oct 1931 | Box 14 \ 6 Scan210 | |
| The failure of a mild steel exhaust chamber and the need for further experimental work. | 9th Oct 1931 | Box 14 \ 6 Scan211 | |
| Note about testing a new mild steel front suspension member and pipe for a 15,000-mile run. | 9th Oct 1931 | Box 14 \ 6 Scan212 | |
| Power loss in the P.2 exhaust system and the effect on continental type cars with existing silencers. | 9th Oct 1931 | Box 14 \ 6 Scan213 | |
| Graph showing the results of power tests on a PII unit, comparing performance with an open exhaust versus a standard silencer. | 9th Oct 1931 | Box 14 \ 6 Scan214 | |
| Blank document page with a purple date stamp from Derby. | 9th Oct 1931 | Box 14 \ 6 Scan215 | |
| Request to issue marked up prints for testing Phantom II exhaust system fittings without lagging. | 12th Oct 1931 | Box 14 \ 6 Scan216 | |
| Providing marked-up blueprints for Phantom II exhaust fittings and experiment instructions. | 13th Oct 1931 | Box 14 \ 6 Scan217 | |
| Suggesting a testing method for the P.2 exhaust system to identify the source of significant horsepower loss. | 1st Oct 1931 | Box 14 \ 6 Scan218 | |
| Requirement for larger exhaust silencers on the P. 2 and 25HP cars. | 20th Oct 1931 | Box 14 \ 6 Scan219 | |
| Distortion issues and the need for stiffening the Phantom II exhaust system flange. | 22th Oct 1931 | Box 14 \ 6 Scan220 | |
| Request to manufacture a modified exhaust fish-tail with a 50% larger outlet area for testing on a Continental P.II. | 2nd Nov 1931 | Box 14 \ 6 Scan221 | |
| Tests on the Phantom II exhaust system to investigate power losses and potential improvements. | 2nd Nov 1931 | Box 14 \ 6 Scan222 | |
| Graph plotting Brake Horse Power and Brake Mean Effective Pressure against RPM to show power losses from different exhaust system configurations. | 2nd Nov 1931 | Box 14 \ 6 Scan223 | |
| Blank document page with a purple ink stamp from the Print Room in Derby. | 2nd Nov 1931 | Box 14 \ 6 Scan224 | |
| Performance graph analyzing losses in a Phantom II short type silencer exhaust system. | 2nd Nov 1931 | Box 14 \ 6 Scan225 | |
| Performance graph analysing power losses in a Phantom II short type silencer exhaust system. | 2nd Nov 1931 | Box 14 \ 6 Scan226 | |
| Cover sheet with a 'Print Room' stamp. | 2nd Nov 1931 | Box 14 \ 6 Scan227 | |
| Exhaust silencers for P. 2. & 'U' Series 25HP, suggesting spot welding instead of riveting. | 20th Nov 1931 | Box 14 \ 6 Scan228 | |
| Request to make an experimental silencer for a Phantom II car with a 2.50' downtake pipe. | 27th Nov 1931 | Box 14 \ 6 Scan229 | |
| Blueprint for an experimental silencer designed to suit a 2.50 inch diameter intermediate pipe. | 25th Nov 1931 | Box 14 \ 6 Scan230 | |
| Proposed modification to the Phantom II exhaust system to reduce noise. | 27th Nov 1931 | Box 14 \ 6 Scan231 | |
| Blueprint of a PTT exhaust system with small diameter pipes. | 27th Nov 1931 | Box 14 \ 6 Scan232 | |
| The results of tests on exhaust system losses using a 114° camshaft. | 2nd Dec 1931 | Box 14 \ 6 Scan233 | |
| Performance graph comparing a full exhaust system against a manifold-only system with the cut-out open. | 30th Nov 1931 | Box 14 \ 6 Scan234 | |
| Stamped by the print room. | 1st Dec 1931 | Box 14 \ 6 Scan235 | |
| Performance graph analyzing a short type exhaust system under various configurations. | 30th Nov 1931 | Box 14 \ 6 Scan236 | |
| Almost entirely faded document with a 'Print Room' stamp in the bottom right corner. | 1st Dec 1931 | Box 14 \ 6 Scan237 | |
| Quarterly complaints report regarding noise issues with the Phantom II exhaust cut-out system. | 1st Feb 1932 | Box 14 \ 6 Scan238 | |
| The discontinuation of exhaust cutouts on 40/50's (Phantom II) from the N.2 series onwards. | 2nd Feb 1932 | Box 14 \ 6 Scan239 | |
| Customer complaints about the Phantom II exhaust cut-out and proposing a modification. | 2nd Feb 1932 | Box 14 \ 6 Scan240 | |
| Work on intake & exhaust silencers and steering systems for cars. | 14th Apr 1932 | Box 14 \ 6 Scan241 | |
| Work and modifications for a P.2 resonance-type exhaust silencer. | 20th Apr 1932 | Box 14 \ 6 Scan242 | |
| Blueprint for a fishtail exhaust adaptor for 40/50 or 25 HP models. | 22th Apr 1932 | Box 14 \ 6 Scan243 | |
| Largely blank or faded document with a date stamp from the Print Room. | 22th Apr 1932 | Box 14 \ 6 Scan244 | |
| Blueprint of a double resonance unit designed to be fitted onto a pipe. | 22th Apr 1932 | Box 14 \ 6 Scan245 | |
| Blueprint showing two pipe assemblies, one standard and one for a 25 HP application with a fishtail exhaust. | 22th Apr 1932 | Box 14 \ 6 Scan246 | |
| Largely illegible or blank document with a 'Print Room' date stamp. | 22th Apr 1932 | Box 14 \ 6 Scan247 | |
| Modifications to resonance type exhaust silencers for long and short Phantom II chassis. | 25th Apr 1932 | Box 14 \ 6 Scan248 | |
| Request to modify exhaust pieces for the Phantom II Resonance Exhaust System according to specific sketches. | 1st Jun 1932 | Box 14 \ 6 Scan249 | |
| Duplicate report detailing a series of comparative tests on exhaust systems for two experimental car models. | 8th Jun 1932 | Box 14 \ 6 Scan250 | |
| Log of daily tests conducted on an exhaust system, modifying components and measuring performance improvements. | 29th Oct 1931 | Box 14 \ 6 Scan251 | |
| Series of tests on exhaust system configurations, materials, and their performance. | 1st Nov 1931 | Box 14 \ 6 Scan252 | |
| Test results for different straight-through exhaust pipe configurations and a cast iron expansion box. | 26th Nov 1931 | Box 14 \ 6 Scan253 | |
| Proposed changes to the 40/50 exhaust system, from Staybright to Mild Steel, to eliminate noise. | 9th Jun 1932 | Box 14 \ 6 Scan254 | |
| Phantom II exhaust system and silencer design for the 20/25 and 40/50 models. | 29th Jul 1932 | Box 14 \ 6 Scan255 | |
| Continued note on testing a Silver Ghost, detailing a 7 BHP performance increase by modifying a pipe. | 29th Jul 1932 | Box 14 \ 6 Scan256 | |
| Graph of resonance silencer exhaust tests comparing BHP and back pressure against RPM. | 20th Apr 1927 | Box 14 \ 6 Scan257 | |
| Stamped document from the print room in Derby. | 8th Aug 1932 | Box 14 \ 6 Scan258 | |
| Exhaust valve failure on a Phantom II during an endurance run. | 2nd Aug 1932 | Box 14 \ 6 Scan259 | |
| Chrome iron exhaust manifold that failed during testing due to contraction and shrinkage. | 6th Sep 1932 | Box 14 \ 6 Scan260 | |
| Instructions for five new features to be incorporated into the Continental type Phantom II chassis, including the exhaust system. | 20th Sep 1932 | Box 14 \ 6 Scan261 | |
| Standardisation sheet for a non-resonant type of silencer to be fitted on all continental cars. | 22th Sep 1932 | Box 14 \ 6 Scan262 | |
| Standardisation and testing of the Phantom II resonance type silencer for Continental cars. | 23th Sep 1932 | Box 14 \ 6 Scan263 | |
| Fix for stretching exhaust valves on customer cars by fitting new heavy-type valves and stronger tappet springs. | 23th Sep 1932 | Box 14 \ 6 Scan264 | |
| Agreeing to standardise the P.II. resonance type silencer for the Continental model. | 27th Sep 1932 | Box 14 \ 6 Scan265 | |
| Proposal to modify exhaust valve guides and cylinder bosses for the Phantom model following a test failure. | 1st Oct 1932 | Box 14 \ 6 Scan266 | |
| P.2 exhaust valve guides overheating and the potential benefits of trying salt cooling. | 14th Oct 1932 | Box 14 \ 6 Scan267 | |
| Experimental work carried out on Phantom model valves and guides to resolve rattling and seizure issues. | 14th Oct 1932 | Box 14 \ 6 Scan268 | |
| Fitting of new exhaust valves and a modification to the valve guides to prevent rattling. | 14th Oct 1932 | Box 14 \ 6 Scan269 | |
| Accompanying two unnumbered blueprints for a P.2. resonance type silencer and swan neck. | 20th Oct 1932 | Box 14 \ 6 Scan270 | |
| Standardisation of a new type exhaust valve and stronger tappet springs for standard cars. | 22th Sep 1932 | Box 14 \ 6 Scan271 | |
| Standardisation of chassis parts form detailing costs and fitting dates for new parts on an O.2. Series chassis. | 19th Nov 1932 | Box 14 \ 6 Scan272 | |
| Standardisation of chassis parts, specifically improved exhaust valves made in S/SLV. | 6th Sep 1932 | Box 14 \ 6 Scan273 | |
| Report form concerning the standardization of chassis parts. | 25th Jan 1933 | Box 14 \ 6 Scan274 | |
| Requirement for elongated silencers due to body designs with luggage lockers and potential exhaust issues. | 25th Jan 1933 | Box 14 \ 6 Scan275 | |
| Exhaust system fumes and booms on Phantom models with overhanging backs. | 30th Jan 1933 | Box 14 \ 6 Scan276 | |
| Testing of extended exhaust pipes on Phantom models to address exhaust booming. | 6th Feb 1933 | Box 14 \ 6 Scan277 | |
| Experiments on the Phantom exhaust system for chassis 104-MY. | 22th Feb 1933 | Box 14 \ 6 Scan278 | |
| Vibration boom period issue with Phantom II chassis 12-MY. | 4th Mar 1933 | Box 14 \ 6 Scan279 | |
| Procedure to potentially reduce 'booming' in new cars and requesting information on its effectiveness. | 23th Feb 1933 | Box 14 \ 6 Scan280 | |
| Vibration boom periods, an invitation to test a new car, and the use of rubber for insulation. | 24th Feb 1933 | Box 14 \ 6 Scan281 | |
| Arrangement to test an extended exhaust pipe on a 20 MY car. | 24th Feb 1933 | Box 14 \ 6 Scan282 | |
| To J.L.E. arranging a trial of extended exhaust pipes on a 20.MY model. | 27th Feb 1933 | Box 14 \ 6 Scan283 | |
| Arranging a visit to London to test a trials car fitted with extended exhaust pipes. | 28th Feb 1933 | Box 14 \ 6 Scan284 | |
| Follow-up memo regarding the testing of extended exhaust pipes on a 20 MY vehicle. | 3rd Mar 1933 | Box 14 \ 6 Scan285 | |
| Design and testing of extended exhaust pipes and fishtails. | 6th Mar 1933 | Box 14 \ 6 Scan286 | |
| Fitting of extended 'fish tail' exhaust pipes on the 40/50 HP chassis. | 9th Mar 1933 | Box 14 \ 6 Scan287 | |
| Standardisation of a complete exhaust system with a resonant silencer to reduce cost and exhaust boom. | 22th Sep 1932 | Box 14 \ 6 Scan288 | |
| Record detailing the introduction of a new part to a chassis series, including costs and testing date. | 19th Nov 1932 | Box 14 \ 6 Scan289 | |
| Tests and issues with extended exhaust pipes, leading to a decision to cease providing them. | 4th Apr 1933 | Box 14 \ 6 Scan290 | |
| Modifications to the exhaust swan neck on chassis GLR-56 for Miss Lucy Logan. | 5th Apr 1933 | Box 14 \ 6 Scan291 | |
| Preparation and despatch of an extended exhaust pipe for chassis GLR-56, belonging to Miss Lucy Logan. | 6th Apr 1933 | Box 14 \ 6 Scan292 | |
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