From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
10,007.25-mile trial, detailing routes, performance, fuel consumption, and post-trial engine condition.
| Identifier | ExFiles\Box 1\2\ B001_X 53-page24 | |
| Date | 27th February 1920 | |
| hill, i.e., the clutch and gear were not disengaged. The mileage covered was 10,007.25 miles. The trial was held on the Six Standard Trial Routes of the Club, which radiate from London. One of these routes was used each day, each route thus being covered ten times in the trial. The routes are as follows:— 1. Cheltenham Road to Northleach, via Uxbridge, High Wycombe, Oxford and Witney ... 168¾ miles 2. Exeter Road to Longbarrow Cross Roads, via Hounslow, Staines, Basingstoke, Andover and Amesbury ... 165½ " 3. Peterborough (Great North Road) via Barnet, Hatfield, Baldock, Biggleswade and Buckden ... 167½ " 4. Stratford-on-Avon Road to Pillerton Priors via Edgware, Watford, Berkhamsted, Bicester and Banbury 169 " 5. Bath Road to Beckhampton via Hounslow, Maidenhead, Reading, Newbury and Marlborough ... 164½ " 6. Coventry Road to one mile past Dunchurch, via Barnet, St.{Capt. P. R. Strong} Albans, Dunstable, Towcester and Daventry ... 164¼ " The car returned to the Club depôt (Pall Mall) every night, consequently a proportion of each day's run (morning and evening) was through London traffic. The road conditions during the whole trial were approximately as follows:— 66 per cent. good, 23 per cent. fair, 11 per cent. bad. The trial occupied 61 days, and rain (at times a little snow) fell on 24 days. With the exception that adjustments were made to the carburettor on the 3rd and 8th days, and that the throttle and air-valve were cleaned before the start on six days, no adjustment or work was done on the car during the whole distance of 10,007.25 miles. Water was put into the radiator once only, on the 51st day. The lubricating oil in the engine was drawn off and replaced with fresh oil four times during the trial, the oil consumption being 935.25 miles per gallon. The total amount of benzol used during the trial was 561.5 gallons, giving a consumption for the whole distance of 17.82 miles per gallon, equivalent to an average consumption of 42.87 ton-miles per gallon. The consumption of benzol during each respective 1,000 miles run was as follows:— 1st 1000 miles ... 17.6 miles per gallon 2nd " " ... 17.9 " " 3rd " " ... 18.2 " " 4th " " ... 18.3 " " 5th " " ... 17.7 " " 6th " " ... 17.8 " " 7th " " ... 17.9 " " 8th " " ... 17.8 " " 9th " " ... 17.3 " " 10th " " ... 17.7 " " The trial was run at an average speed of 19.9 miles per hour (running time only). During the period between the carburettor adjustments on the third and eighth days, the engine missed at times, due to the fact that the supply of benzol was reduced to the slow-running jet at the first adjustment. This misfiring ceased when the original adjustment was restored on the eighth day. At no time was there any emission of smoke. The engine did not start easily from cold, but was not unduly hard to start. When warm the engine started easily at all times. Condition after the Trial.—The engine was dismantled after the trial in order that its condition might be compared with the condition prior to the start of the trial. The exterior of the engine was moderately clean, there having been only a small amount of lubricating oil leakage (not enough to affect the consideration of lubricating oil consumption). The general condition of the engine as regards deposit was what would be considered good, after running 10,000 miles, whether the fuel had been benzol or petrol. The deposit on the piston heads was uneven, being slight over the major portion of the head but somewhat heavier on the side remote from the valves. The stems of the valves all of which had been seating properly, were in good condition, were a good fit in the guides and showed no measurable wear during the trial. The valve facings and seatings were in very good condition considered in relation to the mileage. The cylinders and pistons were all in excellent condition, and measurements showed that no measurable wear had occurred during the trial. The rings were in good condition, but on two pistons the top rings were not properly free in their grooves owing to hard deposit. The plugs, which were neither cleaned nor changed during the trial, were in excellent condition. A chemical investigation of the characteristics of the lubricating oil before use and after 1,050.5 miles use showed that the oil contained no trace of benzol after use. J.{Mr Johnson W.M.} W. ORDE, Secretary. Pall Mall, London, S.W. 27th February, 1920. ARTHUR STANLEY, Chairman. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} H.{Arthur M. Hanbury - Head Complaints} BAILLIE, Vice-Chairman of Technical Committee. [Handwritten Annotations and Stamps] a.o.k 28/11/24 [Stamp]: RECEIVED 28 NOV 1924 R E A D [Handwritten]: ESX SH John Edmund under this file | ||