That Fastest Ever 30/98
In The Motor dated January 13th, “King-Pin,” a regular contributor to that journal, published two paragraphs on the 30/98 Vauxhall car which, raced at Brooklands by R. J. Munday, lapped at 114.23 m.p.h. in the course of winning the Gold Star race at the 1932 B.A.R.C. Whitsun Meeting, thereby, and rightly, establishing a claim to be the fastest 30/98 in the world.
“King-Pin” describes how this excellent speed was attained, claiming that be gives the facts “for the first time in print.” R. J. Munday’s claim to have possessed the fastest-ever 30/98 we do not dispute, but for the sake of fair play it should be put on record that whereas The Motor of January 13th contained a sprinkling of facts about this interesting Vauxhall, the story, in more technical and, we think, more accurate detail, appeared fire years earlier, on pages 479/480 of the second volume of “The Story of Brooklands,” by W. Boddy.*
Boddy tells us that he wrote to The Motor to point this out, in fairness to his publisher; to date his letter has not appeared in print.
The account, as it appears in “The Story of Brooklands,” was obtained after a personal interview with Mr. Munday. Whereas “King-Pin” states that the engine on the occasion of the Gold Star race was developing 162 b.h.p. at 3,800 r.p.m., we believe that this output (actually 162.8 b.h.p. according to a Laystall test-house graph shown to Bodily during his interview with Munday) was not realised until 1935, when the Vauxhall engine had been installed in the Sunbeam chassis of the Bainton Special. This latter car had similar, probably greater, frontal area than Munday’s 30/98, yet it reached a lap speed of 117.19 m.p.h., which confirms our opinion that it was not until 1935 that this remarkable Vauxhall engine was developing that astonishing output of nearly 163b.h.p.
“King-Pin” omits to state that the engine had a stroke 10mm. larger than standard in its Gold Star form, giving a capacity increase of 292 c.c., which, together with the modifications referred to in “The Story of Brooklands,” no doubt contributed to the fine performance this stripped four-seater achieved. In its ultimate, Bainton Special, form the engine was over-bored by 2 mm., to 100 mm., but reverted to the standard length of stroke, making its swept volume 4,398 c.c., against 4,234 c.c. of a normal-size OE 30/98, such as that with which T. H. Plowman set up his great 107-miles-in-the-hour at Montlhèry last year.
An interesting feature of the Gold Star race which Munday won so convincingly, finishing 21.8 sec. ahead of E. L. Bout’s supercharged 2-litre Sunbeam, and one which “King-Pin” missed, is that the Vauxhall lapped not once, but twice, at 114.23 m.p.h. The actual lap speeds of the car throughout the race were: 91.72, 112.68, 114.23, 113.45, 114.23. and 111.67 m.p.h. So there is no quibble about Munday’s magnificent run, only over who first released the “inside” story!
*“The Story of Brooklands, 1906-1940,” by W. Boddy. (Grenville Publishing Co., Ltd., 15, City Road, E.C.1. In three volumes, 12s. 6d. per volume.)
The New Alta G.P. Engine
The new four-cylinder 93.5 mm. by 90 mm., 2,470 c.c. Alta Grand Prix engines will be used by Connaught this season. The engine has an aluminium-alloy top-half crankcase carrying an inserted one-piece cast-iron cylinder block to greatly increase the beam stiffness of the whole engine. Magnesium-alloy bottom-half crankcase made in one with the main bearing caps and sump, so that when the bottom half is removed the crankshaft can be withdrawn and the whole of the interior of the engine cleaned and easily examined. The integral sump materially increases the beam stiffness in all directions.
The cylinder head is secured by 28 head studs to hold it onto the top-half crankcase, and it consists of an aluminium-alloy casting with separate cam bearings bolted to it, and carries the two valves at 72 deg. operated by twin overhead camshafts. The inlet valve is 2 in. diameter, and the exhaust valve 1 3/4 in. diameter. Interposed between the camshafts and the valves are high-tensile steel valve rockers to remove the damaging effects of side thrusts on the valve stems. The valves have chromium-plated stems to enable them to run with small clearance in the cast-iron valve guides, and thereby enhance the flow of heat from one to the other.
The cylinder head has a one-piece Elektron valve cover, and provision has been made for preventing the small stones that get on these valve covers from falling down the sparking-plug holes.
A great deal of design work has been done regarding the flow of water in the cylinder head on the basis that water has to be made to flow most definitely in the direction that one wants it to, and nothing may be left to chance. The water is conducted by a pipe to the off-side front face of the cylinder block, and travels down a cast gallery in part in the head, and in part in the cylinder block, so that the water scours at high velocity and is conducted round the exhaust valve seatings and ports cooling this very vital area with the coldest water direct from the bottom of the radiator.
Having passed from front to back of the cylinder head, the water takes a 180-deg. turn and returns along the cylinder head from the back to the front. In this way one ensures that the whole cross-section of the cylinder head is adequately cooled by a fast-flowing stream of water, and that the head is free from stagnant pockets.
Conversely, the inlet ports are projected outside the cylinder head proper, to be as far from the water as possible, in order that the heat from the water may not be transmitted to them, thereby expanding the inlet charge and lowering the volumetric efficiency.
The one-piece Nitralloy crankshaft is fully counterbalanced and runs in three Vandervell copper-lead bearings of adequate size in the aluminium crankcase. The oil from the forward-mounted pressure gear pump is delivered by cast-in ducks to the front and rear main bearings only. It then flows through the crankshaft to the big-ends by means of internal drillings provided with adequate sludge traps, and additional drillings which take the oil to the centre main bearing. In this way this heavily loaded bearing is always lubricated due to the rotation of the crankshaft at the point of minimum pressure. and this has a great bearing on its long life and freedom from heating.
The connecting-rods have had a great deal of design experience expended upon them, and are made from nickel-chrome molybdenum steel drop forgings, machined all over and balanced. They are of a very adequate section to withstand the heavy stresses to which they are subjected.
At the big-end they are provided with Vandervell copper-lead hearings, and at the small-end have a bronze bush in which the internally-tapered section gudgeon-pin floats. The gudgeon-pin is secured in the piston by round wire-type circlips to prevent it rubbing the cylinder walls.
The pistons are of “Hepolite” manufacture and incorporate a specially designed shaped crown. This special shape of crown has been found necessary with alcohol fuel in order that one may get as uniform and thin a gas layer as possible, to transmit sufficient heat into the alcohol-saturated charge in order that speedy burning may be attained, and flame damping due to excessive cooling of the charge eradicated.
This feature is designed not to cause bad filling by overheating the charge, because by the time it becomes operative the inlet valve has closed. The pistons are of larger diameter than the cylinder head, thereby providing a “squish” action to further break up the charge and promote efficient burning at high revolutions.
A great deal of work has been done on disposition and direction of the airflow in the cylinder head to promote efficient burning, and in this connection the fuel/air mixture is taken through short stub pipes which incorporate the seatings for the nozzles for the S.U. fuel injection pump, which delivers the fuel to the engine.
At the front of the crankcase there is a cast-Elektron drive case incorporating two vertical drives by Nitralloy skew gears running in oil, and driven from the crankshaft. This provides a drive for the water pump on one side, and for the pressure and scavenge oil pump on the other, the Scintilla fixed-ignition magneto being driven from the same source.
This engine follows the arrangement developed on the previous 2-litre engines by incorporating the two-point mountings on the centre of the crankcase on the centre of gravity of the engine. There is an additional mounting at the rear of the crankcase, or on the gearbox to stop the engine rocking about its centre mounting. This type of engine mounting has been developed after a great deal of thought, to reduce the torsional stresses on the crankcase, and thereby prevent the crankshaft from being subjected to excessive bending loads, consequently lowering the mechanical efficiency.
It has been found that this mounting, peculiar to these engines, contributes materially to the reduction of the stresses in the crankshaft, and in the crankcase, and has been proved by practical experience to be a very desirable feature.
The manufacturers state that the first two engines have already been delivered, and a further twelve are well on the way to completion; they anticipate delivering the whole of this batch by about the end of May.
The engine weighs complete 340 lb., dry.