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).
Page from 'The Autocar' magazine featuring reader correspondence on sports cars, two-stroke engine design, and vintage vehicles.
| Identifier | ExFiles\Box 160\5\ scan0174 | |
| Date | 15th November 1940 | |
| November 15th, 1940. The Autocar 505 Correspondence some idea of the delicacy of the operation. Upon reaching the opposite shore the same procedure has to be adopted in reverse. My party was the first to make the trip to Cape Wrath that season, and extremely interesting it was. The road, though rough and narrow, is quite passable for cars up to 12 h.p. and, in fact, is used for taking supplies to the Cape Wrath lighthouse. Actually it compares quite favourably with many other roads in that part of Scotland, being no worse than the Pass of the Wild Cattle, for instance, as far as surface is concerned, and naturally not possessing such bends and gradients as that climb. When sanity returns to the world I look forward to resuming my explorations of this most interesting part of the country, and to perhaps meeting Mr. Lobel upon one of those lonely stretches of road that so appeal to us. E.{Mr Elliott - Chief Engineer} H.{Arthur M. Hanbury - Head Complaints} GREGORY. Brighton. "TALKING OF SPORTS CARS" A Reader's Ideal [49853.]—I read with great interest the article under this heading in your issue of November 1st. To my mind, this hack described is the perfect car, in spite of its mileage, and I would give my right arm to possess such a model. The article in question gave a wealth of information that even an amateur could not afford to miss. I assume that only a privileged few could obtain such a car which, in this case an A.M., means the hall-mark of perfection. I look forward to more interesting articles in your journal, and hope one day to be the proud possessor of such a hack. With every wish of success to you in spite of the times. A CONTINUOUS READER. West Dulwich, S.E.21. [As was explained in the article in question, the car referred to was purely a works experimental machine, and there would, of course, be no possibility of such a car being sold in the ordinary way.—ED.{J. L. Edwards}] THE EVERYMAN CAR Two-stroke Engine Design [49854.]—The subject of future car design is always a fascinating one, and I was much interested in Mr. Slade Kennedy's proposals (The Autocar, September 27th), especially in the somewhat unusual design of two-stroke engine. I agree that a two-stroke is very attractive where cost of production is a primary consideration, and, considering its other inherent advantages, I think that the development work necessary to put it "on the map" would be well worth while. As a result, however, of my own work in this connection I should like to offer a few comments on the particular design suggested by Mr. Kennedy. The power output per litre of a two-stroke is usually somewhat less than that of a four-stroke, and it would therefore be desirable to use an engine of the largest possible capacity consistent with the lowest tax rating of 6 h.p. This gives a bore of 49 mm., but a long stroke is both permissible and desirable. Taking the same stroke-bore ratio as the Trojan had, we should have a stroke of 94 mm., giving a capacity of 708 c.c. This should give a more satisfactory performance than the 570 c.c. proposed. The "A" cylinder layout is apparently preferred to the "U" (Trojan) type because it avoids the differential piston movement at t.d.c. associated with the latter. Just why this is considered undesirable is not quite clear, as it appears to me to have no real drawbacks and some definite advantages, one of the more obvious being the better timing obtainable for the inlet port from carburettor to crankcase. There are, however, other and much more serious objections to the in-line "A" design. The cylinder block would not, I fancy, be welcomed in the machine shop, for whereas four parallel cylinders can be bored simultaneously, or at least with the same set-up, separate operations would be needed for the two pairs of cylinders of the "A" system; the same applies to grinding and honing (if any). This would increase the cost. The four-cylinder-in-line arrangement calls for a crankshaft having the two crankpins of each pair in line with each other instead of at 180 deg. as in the usual four-throw shaft, forming in effect a two-throw shaft with elongated crankpins each carrying two con-rods. A two-throw crankshaft cannot be properly balanced dynamically, even as regards the primary inertia forces, and this elongation would increase the unbalanced couple. I do not know how far the illustrations are intended to be accurate—probably they are merely diagrammatic—but there seem to be other details which might well be improved. In fact, the two pictures of the engine do not agree about the port arrangement. I would suggest that the two inlet ports to the crankcase should be in the middle cylinders, so as to make the inlet manifold short and symmetrical—two very important features. I think, too, that the heating arrangements could be improved. By making the outer cylinders the "exhaust" ones and placing the transfer ports on the opposite side of the engine a neat layout could be obtained. The combustion chambers should be offset over the exhaust cylinders, and the plugs over the inlet. On the whole, I prefer the original layout of the Trojan, which, I am convinced, could be developed, in the light of modern knowledge, to a much greater extent than it has been. I should be very glad some day to see it form the power unit of "Everyman's" car, for which purpose it should be eminently suitable. A.{Mr Adams} F.{Mr Friese} SCROGGS. R.A.F. Hospital. VINTAGE SPORTS CARS "History" of a 2-litre Lagonda Would be Welcomed [49855.]—Inspired by the most interesting correspondence on old-type Bentleys and by Mr. T. P. Breen's [49801] kind offer of information concerning "vintage" sports cars—which has probably resulted in his being snowed under by letters from enthusiasts—it occurred to me that someone might be able to give details of a 2-litre Lagonda that I own. It is one of a team of three that was specially built for racing in 1929, and was sent to Le Mans as the sole entry from the works. I have an idea that it subsequently ran in several events at Brooklands and elsewhere, but I have never been able to find out who drove it or what measure of success was attained (if any!) Now if Mr. Breen or any other reader had any experiences with that team or, better still, with the actual car, I should be pleased to hear of them. I am now considering rebuilding and to a certain extent modifying the "barrow," and am anxious to collect data re axle ratios used in racing and of any other modifications employed to boost performance, the figures of which I should very much like to get hold of. The chassis number of the car is 9414. D.{John DeLooze - Company Secretary} R.{Sir Henry Royce} HAGEN. Hempstead, Holt, Norfolk. [This car is illustrated under "Talking of Sports Cars" on page 509, and referred to by "V.{VIENNA}"—ED.{J. L. Edwards}] BOOKS for MOTORISTS Issued in conjunction with "THE AUTOCAR" Net Price. By Post. The Autocar Guide for the "L" Driver ... 1/- 1/2 Look After Your Car... ... 2/6 2/9 The Motor Vehicle ... ... 10/6 11/1 Know Your Car ... ... 1/6 1/8 The Autocar Handbook ... ... 2/6 2/11 Motor Driving Made Easy ... ... 2/6 2/10 More Sketches by Casque ... ... 2/- 2/3 Automobile Electrical Equipmen' ... 10/6 11/1 The Modern Diesel ... ... 3/6 3/11 The Autocar Register ... ... 3/- 3/5 By P. M.{Mr Moon / Mr Moore} Heldt, U.S.A.: High Speed Combustion Engines ... 42/- 42/7 Motor Vehicles and Tractors ... 42/- 42/7 Fuels and Carburettors ... ... 18/- 18/7 High Speed Diesel Engines ... ... 27/- 27/7 Full particulars of any of the above books will be sent on application. Obtainable from Leading Booksellers and Railway Bookstalls or direct (remittance with order) from ILIFFE & SONS LTD., Dorset House, Stamford Street, London, S.E.1. A25 | ||