G.N. Gen.

The touring G.N. has, we fear, without exception, gone from amongst us, although MacLagen of the “Scuderia Chemvamo” is hoping to revive an example bought recently from T.P. Breen. Peter O’Reilly was one of the last persons to appear with such a car, but its remains are now useful only as spares. Nevertheless, the G.N. in sprint form is almost certainly going to be with us in post-war sprint events, and those who are working on such cars will read with interest this chronological description of the standard G.N. models, written by John Bolster himself, who pays the marque the great compliment of saying that it shares a place in his memory with the “30/98” Vauxhall. – Ed.

It is now so long since the G.N. car went off the market that some of my younger readers may never have seen one in its original form. The G.N. chassis lent itself so well to “Special” building that there were a number, more or less drastically modified, racing in sprint events right up to the start of this war, which is rather astonishing, considering that they were produced as an ultra-cheap utility car.

The earliest type of G.N., built just before the last war, had a side-valve air-cooled twin-cylinder engine set with its crank across the frame, driving the rear wheels through two enormously long belts. It was a sporty-looking little machine, with a pointed cylindrical petrol tank mounted over the engine, and the steering was by a cable passing, over pulleys and round a bobbin on the steering column, which, surprisingly enough, gave very light and accurate control. H.R. Godfrey and A.G. Frazer-Nash built the first few cars in the stables of the latter’s home, so the car was designed to be as simple to produce as possible.

Shortly after the last war a new model was designed, and was built more or less unchanged for several years. This was the type which “Special” builders still seek, and was a very popular car, selling well from 1921 to 1925.

It consisted of a rectangular channel section steel chassis frame, the two straight side members being joined together in front by a cross member and strengthened by gusset plates riveted at the corners. The frame was about 3 1/2″ deep by 1/8″ thick, with 1 1/4″ flanges. Apart from the engine bearers, there was only one other cross member, which was bolted to the rear spring brackets. The front axle was tubular, with plain bearing hubs, and quarter elliptic springs above the axle, plus strip steel radius arms below, looked after the suspension. The rear axle was solid, 1 1/2″ in diameter, and was carried on ball bearings of the cup-and-cone type, with strong radius arms and quarter elliptic springs. The wire wheels wore 700 x 80-mm. beaded-edge tyres and were of the centre-locknut type, the drive from hub to wheel being by seven dogs on the earlier cars and three dogs on the later ones. The wheelbase of the standard 2-seater was 8 ft. 6 in. and the track 3 ft. 6 in. These cars were not crab tracked.

The standard engine was designed to require as little accurate machining as possible, and bore no relation to the motor-cycle type of V-twin with inside flywheels. The aluminium crankcase had a long extension to the rear and contained an overhung crank. This was a built up affair, consisting of a shaft with a taper at each end, which lived in the rear crankcase extension in a bronze bush. The heavy flywheel was mounted on the rear taper and the crank web and balance weight on the front one, the crank pin being held in place by a large nut. The two con. rods, one of which was forked, had a bronze bush, and the overhanging front end of the crank-pin fitted loosely into a hole in an arm, which was carried by a shaft projecting from the front cover of the crankcase. This drove the timing gears and the magneto.

The two cylinders were mounted at an angle of 90˚ and had overhead inlet and side exhaust valves. The single carburetter was exhaust-heated and was fed by gravity from a dashboard petrol tank. The front engine bearers were bolted to the crankcase, but the rear engine bearer had a hole in the centre, in which the crankcase extension was free to turn, to allow for chassis whip. The single-plate clutch was carried on four pegs on the flywheel, the powerful clutch spring being on the propeller shaft. It was designed so that the clutch thrust would be taken rearwards by the transmission, and not forwards, as the crank had no provision for making end-thrust.

The transmission was one of the most famous features of the G.N., and was remarkable for its simplicity and efficiency. The propeller shaft had no universal joint. The front of it was supported on a spigot, fitting into a bush in the centre of the flywheel, and the rear by the bevel box. The bevel box consisted of three parts – the two halves and the extension. The extension contained the ball-races, radial and thrust, in which the propeller shaft ran, a straight-toothed pinion being secured to a taper on the end of the shaft. The pinion drove a bevel, which was keyed to the centre of the bevel shaft. The bevel shaft emerged from each side of the bevel box and was supported in self-aligning ball-races in aluminium housings bolted to the chassis side members.

Thus the whole outfit was supported at three points – the two bevel shaft ball-races and the spigot bush – and the torque reaction was taken by the propeller shaft. Unlike the Frazer-Nash, the bevel box was not fixed to the chassis in any way.

On each side of the bevel shaft was a key, which drove, on one side, a double dog and, on the other, a combined dog and gear. The double dog, could be slid into engagement with either of two sprockets, and the other dog either with a sprocket or a gear. The three bevel shaft sprockets were connected by 3/4″ x 7/16″ chains to three different sized sprockets on the rear axle, thus providing the three forward speeds, and the gear drove a sprocket in the opposite direction to give reverse through a fourth chain. The dogs were controlled by a pair of selectors and a right-hand gear lever. An adaptor was screwed into the offside end of the bevel shaft for a starting handle, so that one wound one’s G.N. up from the side, just in front of the back wheel.

The car was normally fitted with a very smart 2-seater body with a small dickey seat. Long, low and rakish, its dummy radiator set well back and its large steering wheel carried into the driver’s lap, it was easily the smartest small car on the market. The very high-geared steering was light and positive, and the road-holding and suspension were miles ahead of the typical light car of the period. The gear change was much better than the normal gearbox of that date and there was not that horrible noise which every cheap gearbox was expected to make on the indirects. With all these virtues, plus its low first cost and economical running, it was deservedly popular, but it had its faults. The engines were incurably noisy. and they varied a great deal in their reliability. The design was sound enough, but I have come across poor workmanship and bad material in some of them. Given a mechanically-minded owner, a lot of them gave very satisfactory results, and they were certainly delightful to drive. With the solid axle and splendid road-holding, one hardly noticed that one had only rear wheel brakes, their stopping power being remarkably good. So much for the standard model.

The sports and racing G.N.s were extremely fast, doing very well at Brooklands and being absolutely unbeatable in sprint events. The most remarkable thing about them was that the standard chassis was always used, though some of the sprint cars had a shorter wheelbase, and Capt. Frazer-Nash had a longer chassis for Brooklands. The engines were all 90˚ V-twins, of 84-mm. bore x 98-mm. stroke, giving 1,086 c.c. A certain amount of competition work was done with the “O.H.V. Conversion” engine, and quite a number were sold to private owners. It consisted of a vertical o.h.v. head fitted to the standard engine, the valves being operated by push-rods. This gave a considerable increase in urge, but the standard bottom half would not put up with too much use of the loud pedal, and the strength of the valve springs was limited by the rather skimpy timing arrangements. Nevertheless, they went very well and were good enough to win the 1,100-c.c. class in several events. Later there was another push-rod head called the “Frazer-Nash Conversion,” which had inclined valves.

The first type of genuine racing engine was the “Mowgli,” and this was also available in a super-sports G.N. called the “Vitesse.” It had an entirely special crankcase, with all parts proportioned to take the increased urge and a rollerbearing big-end. The valves were inclined and each cylinder had its own overhead camshaft, which operated the valves through rockers. The camshafts were driven by an exposed 5/8″ x 3/8″ chain of enormous length, which was tensioned by a jockey sprocket. This engine was one of the most reliable pieces of machinery ever made. My brother had one, which he hotted up considerably, and it gave him a lot of most enjoyable racing, but it was on the road that it was most delightful. The acceleration was tremendous and I have never driven a car with a better top gear performance. The fact that my brother got it up Shelsley in 49 secs. will give some idea of its urge, and it would climb a 1-in-5 gradient on top gear at a rousing speed. I was very pleased to hear recently from Cpl. Green, R.A.F., the present owner of this splendid old engine, that it is in 100 per cent. condition and sounds healthy still. H.J. Aldington used to have a most beautiful “Vitesse” 2-seater with one of these engines, and it went like a flash, the staccato crackle of the twin merging into a steady roar at round about the 80-m.p.h. mark. The car and driver used to get a liberal dose of oil from the exposed o.h.v, gear, and Castrol “R” at that, but it was worth it.

The later racing engine was called the “Akela,” and had four valves per cylinder with pent roof heads. The camshafts were driven by enclosed vertical shafts and two magnetos were fitted. This was a really beautiful-looking engine, with none of the “rough but strong” appearance of the older G.N. machinery, and it did very well in racing. As turned out originally there was a weakness in the camshaft gears and severe damage could result if they were stripped, became it usually caused a valve and piston to collide. With that trouble cured, though, the “Akela” was a thoroughly sound engine and kept its oil inside better than the “Mowgli” did. I always preferred the “Mowgli” because it was such fun seeing all that machinery rushing round and round!

Most of the racing chassis had a fourth forward speed instead of the reverse, though the o.h.c. engines were so flexible that this was hardly necessary. For sprint work it was usual to fit a single-seater body, or no body at all, and transfer the steering to the centre of the car. It was easy to lower the chassis by putting wedges under the springs, and one could fit shock absorbers if desired, though it was a common mistake to do these up too tight. My brother’s car was perfectly steady at maximum speed with the shockers slacked right off, in spite of being a foot shorter than standard. After the engine was hotted up it would do 87 m.p.h. with a 2-seater body, but we never checked its maximum in monoposto form.

The G.N. firm had business connections in France and a lot of G.N.s were made over there. The Salmson was developed from the G.N., and I believe it was the French side of the business, more than anything else, which went wrong and got the firm into difficulties. Be that as it may, the “N” of G.N.s left the firm and continued to race and sell the “Akela” under the name of Frazer-Nash, also making a few enormously powerful cars with 1 1/2-litre two-cylinder engines. (Remember Basil Davenport’s “Spider”?) G.N.s forsook the sports car and built an entirely new model, with shaft drive and disc wheels. It could be had either with a side-valve air-cooled twin, which was much quieter – and slower – than the old I.O.E. engine or a four-cylinder watercooled unit. If I remember aright, this was a push-rod o.h.v. affair of about 1,200 c.c. and was made in France. This was rather an ordinary little car and not to be compared with a “real” G.N.

Meantime, Archie Nash had redesigned the chain-driven chassis, and it now had genuine Rudge wheels and a much stronger front axle, among other things. The famous Frazer-Nash radiator appeared for the first time and the engine was a four-cylinder Powerplus o.h.v. of 1 1/2-litres capacity. These cars also had that cunning device to stop you getting into two speeds at once, and the famous bulbous-tailed 3-seater aluminium body. The Powerplus engine was rather on the delicate side, but Hugh Ebbutt was still running a “Plus Pip” Nash shortly before the war.

The G.N. concern had more or less given up manufacture and were doing ordinary garage work, but they suddenly threw away the shaft-driven chassis and reappeared with the original chain-driven car, this time with the side-valve Anzani engine. The 1 1/2-litre four-cylinder Anzani was an astonishing engine and gave more power than it had any right to do, in spite of its very light construction. Some of the chassis parts, notably the front axle, were not really up to the job, but the complete car weighed only some 10 1/2 cwt. and could leave a contemporary Frazer-Nash standing. This was the G.N.s swansong, but I expect a lot of people remember Halford, of H.R.G.s, doing very well in a quite recent relay race with one of these Anzani-engined cars. Subsequently, Aldington persuaded Nash to fit the Anzani to his cars in place of the “Plus-Pip,” and many Frazer-Nashes of great fame were so powered. (Who will ever forget ” R.G.J.” doing his stuff in “The Terror”?)

I have driven numerous Frazer-Nashes and H.R.G.s, but none of them has had the fascination of a good G.N. “Vitesse.” Their faults were many, but all was forgiven when those two big cylinders were thundering out their joyful song. To say that the G.N. shares a place in my memory with the “30/98” Vauxhall is the highest praise I can bestow on it.