IT is curious, but true, that rumour, persistently repeated and accepted, comes to mean as much as a watertight statement of fact. The A.I.A.C.R. has, one believes, so far, said nothing definite about the 1940 International Grand Prix Formula. Yet nearly everyone in motor-racing is convinced that the Formula will be a simple one of a capacity limit of Ii-litres, with no other restrictions whatsoever—in this country the wish is, perhaps, father to the thought 1

This being the case, quite apart from the great battles we should witness between Mercedes-Benz, Auto-Union, Alfa-Romeo, Maserati, E.R.A., Alta and, I trust but doubt, other grande marques, as well, there are two private-owner ventures which merit widespread attention and appreciation. The gentlemen behind these ventures are none other than Reginald Parnell and Lord Howe.

Parnell is building, not secretly but quite openly, a special 1i-litre roadracing car and Earl Howe is having a supercharged Jameson two-stroke motor installed in his familiar E.R.A. Parnell calls his car the Challenger and it appeared for the first time at the Prescott International Meeting, though they do say it then had a Roots-blown B.R.A. engine installed. Anyway, although it wasn’t rapid it looks as if it is going to be very, very quick indeed. The external lines are definitely imposing ; all very Mercedes-Benz, of quite the latest type. It is surprising how quickly racing car appearances change, for not long ago we all went about saying how very Continent al-i n-t he-Formula-sense were Appleton’s Appleton-Special and Abecassis’s Alta, and now the new E.R.A. and Pamell’s new car, have these worthy cars completely dated, in at all events this one respect. But it is not only in looks that this Challenger is sensational. Its chassis is tubular and. embodies independent front suspension. At the back torsion bars nestle within the tubular frame side-members and a solid axle beam, a /a De Dian, has light radius members and a locating guide in the

centre of the crown-wheel casing. Naturally, the crown-wheel casing, which is in light alloy, is mounted on the frame and drives to the hubs via jointed shafts— as Mercs. and Auto-Union have found right and proper for racing. Luvax friction dampers are used, and they have cockpit control. At the front the hubs are held by very carefully planned transverse wish-bones, supported by vertical coil

springs and frictionally damped. The brakes are Lockheed hydraulic, with the new two-leading-shoe arrangement. The gearbox, now a Wilson help-yourself, may later be replaced by a close-ratio, ordinary box. An open shaft conveys the drive rearwards, and is carried so low that although the driver’s seat is directly above it, nevertheless his head comes only 3 ft. 4 in. nom the ground. The steering is central, to keep the body narrow. There is talk of a rapidly detachable fuel tank, which can be changed during races—one imagines in case of leakage and not as a new means of speeding up the refuelling process 1 In short, an eminently suitable chassis. The detail work and beauty of construction is something of which any country could be deservedly proud. Now Parnell intends to install an entirely special engine in this chassis and that is, very interesting indeed. Even courageous. The designer trusted with the task is Allen. It is a six-cylinder unit of 66.75 x71 mm. (1,492 c.c.) and it can be brought within the 1,100 c.c. class should there be 1,100 c.c. honours to hunt. It is a six-cylinder to avoid undue complication and experimentation, Parnell having had not a little experience of the old six-cylinder M.G. racing unit, for which he devised his own twin-cam head. The block is in alloy with wet steel liners and the head, in alloy with plug-boss and valve-seat inserts, is detach able. The crankshaft runs in seven huge plain bearings and the big ends are plain. The valves, of which the inlets axe larger than the exhausts, are inclined and actuated by twin o.h. cam shafts via piston-tappets. Sodium valve cooling will probably be used. The drive for the camshafts is by gear train, which is sound practice in a racing engine in which noise and cost are of no moment. The pistons are light alloy and the rods of I section. Lubrication is dry sump, from chassis tanks, feed being via a ribbed filter. This simple, yet efficient engine, is supercharged by a special two-stage Roots blower—two-stage supercharge is well known in the aero-engine world and Auto-Union now use it on their Grand Prix cars. The system used on the Challenger has triple rotors and triple carburetters and pressure is variable, up to a peak of something like 40 lb. per square inch—which is blow indeed. The intake system comprises twin threebranch manifolds, the exhaust being on the opposite side of the head. The blower lives ahead of the engine. Pump cooling is naturally made use of. The engine is rubber mounted, though not as in some touring automobiles wherein the gear lever waves like a lily-of-the-field with the engine idling. The design of this new car is certainly inspiring and we shall watch its career in future if litre racing with great keenness, wishing it much more success than has been want to attend lone-ventures in the past. Most of the machining and assembly was done by the Melbourne Engineering Co., hard by the Donington Circuit, which is Michael McEvoy’s concern, and which is a very sound guarantee of the sort of work which has gone into the Challenger’s construction. Not even ” ParnellSpecial “the general addition of “Special” to a car’s name arouse 11’0111 the time when manufacturers got worried as to how modified cars bearing trade names in races would effect their precious reputations, so much so that the J .C.C. stipulated that all entries for the ” 200 ” of that period should be called—Specials, regardless of the fact that losts of privately-owned entries went far better than the makers could ever have made them go. However, whatever Parnell calls his new 11-litre, it deserves striking

success. Those who saw its not very sensational debut at Prescott, and Parnell’s other Misfortunes at that meeting, need not sneer. Since Parnell’s return to racing he has handled that difficult car, the 5litre B.H.W., very well indeed, and its Bugatti engine has served better than any ” 4.9 ” Bugatti with the possible exception of the late Count Czaykowski’s. Earl Howe’s venture is that of having a two-stroke, special Jameson engine installed in his E.R.A. The Jameson two-stroke appeared something like six years ago, and was written up in X.I0ToR SpoRT in August 1933. The Jameson Engine Company, under J. L. J ameson, built a 500 c.c. single which had a speed range of 300-5,000 r.p.m. and gave off 52 b.h.p., or 1.04 b.h.p. per litre, unblown. This engine had the Jameson pistonpattern inlet valve in the head and two 14 nun. plugs. Encouraged by the showing of this single, four-cylinder 996 c.c. racing engines were put in hand. The capacity was kept below a litre in case the A.I.A.C.R. claimed that the 100 c.c. displacement of the piston-valve ranked as cylinder capacity, it being desired to race in Class G. These engines retained the piston inlet valve but were supercharged by twin blowers embodied in the cylinder block, the blowers being specially developed J ameson-Gillett Roots. A solid crankshaft ran in five split rollers bearings and roller big-ends were used. Dry sump lubrication and ignition by twin magnetos was arranged and it was schemed to reduce the weight of the engine from 830 lb. to 220 lb. by using a linered alloy block, the experimental units having iron blocks. A power output of 110 b.h.p, at 4,800 r.p.m. was talked of, or 150 b.h.p. per litre, on petrol! beniole. One of these engines went into a racing chassis built by W. Fenson, using a Delage front axle and big E.N.V. gearbox and another went into a special chassis built up as a competition car for the late Sebag-Montefiore. The former car was to have been driven by Dudley Proy in the ” 500″ and other races and was once entered, I believe, by Sir Malcolm Campbell. It was. a Consistent non-starter and faded right out. The P.M. eventually had a show-finished 2-litre Lagonda engine installed and now Peter Clark is trying to sell it, with V8 motor. The engine for Howe’s car has been designed by Thomas, his head engineer. It is a four

cylinder of 72 x 90 mm. Apparently Jameson eventually realised 139 b.h.p. per litre at only 4,500 r.p.m. from one of his engines, but in a car the power fell to about 70 b.h.p. per litre owing to overheating pistons and ignition maladies. Consequently the new engine has slide valves for inlet and exhaust, the piston inlet valve and conventional outlet ports being scrapped. It is blown by a single blower at 30 lb. per square inch. The crankshaft runs in five bearings, ignition is still by twin magnetos, and there is dry sump lubrication with three oil pumps. There is provision for varying the relative timing of inlet and exhaust valves while the engine is functioning. Certainly Thomas should have a lot of fun with this new machinery, but its potency cannot be overlooked, for it is equivalent to an eight-cylinder fourstroke and if all goes according to plan the output should be in excess of that of Howe’s present, Zoller E.R.A.