Experiences with some small French sports-cars
Contributed by 2nd-Lt. R. S. G. Strachan, whose Second Senechal was more fully written-up in the issue of December, 1938
AN extremely ancient Morgan, so ancient, in fact, that its top speed was under the present legal limit, taught me a lot about internals during the pre-running period when I stripped and rebuilt the unfortunate engine several times. Since then valve and ignition timing have always seemed simple!
Of course, this was a very ancient Morgan, 1920 I think, and not to be compared with the only other machine of that marque with which I ever came in close contact. This belonged to a friend and was one of the original Super Sports models. Fitted with a 1,100 c.c. J.A.P. “twin”—the genuine article with roller-mounted rockers—it had an outstanding performance, and a bark from its twin ports like a two-pounder gun. The brakes were not up to its speed, a rather general failing, I believe.
After the “Moggie” I was presented with an Austin Swallow two-seater, which my parents thought should be safer than anything I might buy myself. I did get a lot of fun from this, even if its top speed was a mere 50 m.p.h. After efforts to purchase an Ulster engine—at a reasonable price had proved abortive, I managed to get hold of an o.h.v. conversion set. Once correctly applied it gave me a maximum of 65, but this proved too much for the old 1928 engine. Consequently a 1931 engine and gearbox were installed and I covered many pleasant miles. About this time—1933—the very pretty J.2. M.G. Midget came on the market and I decided I would build myself a similar body. I started, but having broken up the old body to provide a basis for the new, I was caught when half-way to completion by the advent of my summer vacation—and found I lacked a car in which to enjoy it. I had to get something cheap, and a visit to the local car-breaker’s revealed a £5 1923 Talbot-Darracq Eight two-seater. After the Austin this was very definitely thoroughbred and, indeed, had steering and general manners which I have never matched—except for the brakes!
Despite its ten years, it would still do 60, and a very useful 45 in second. Petrol was consumed at the rate of one gallon in 40 miles and a similar measure of oil was lapped up in 500 miles. This I afterwards found was due to the scraper rings being fitted the wrong way up!
Having fooled around for quite a while with this intriguing little car, I eventually hankered after something with brakes, so I bought a 1928 “Z3″ Senechal. The main attraction was its 14” brake drums. What a disappointment that car was; top speed 50, petrol 30 miles to a gallon, acceleration gradual, and it boiled over every time I came to a hill. My one consolation was the brakes, which did not belie their size and which acted magnificently when the car could be persuaded to run, which wasn’t often.
Such a state of affairs could not be tolerated, so I bought a slightly older Senechal of much slimmer build and of about half the weight of the first. I kept the old engine and gearbox as spares, and since the rest of the old chassis was not interchangeable, I threw it away. This new acquisition was a revelation for an old 1,100 c.c. car of modest design—a genuine 70 m.p.h., 55 m.p.h. in third, and 40 miles to a gallon, made motoring a very joyous business indeed.
The engine still ran very hot, but I traced this to a badly designed exhaust manifold and had a new one built up with a freer passage for the escaping gases which completely cured the trouble.
About the same time a very close friend of mine acquired a 1926 Amilcar. This was a very pretty machine and had extreme urge. The engine was a modest four-cylinder side-valve unit which was mounted low in a very workmanlike frame; the body had a streamline tail and was extremely light, since it was made of aluminium. This Amilcar had rather more speed and acceleration than the Senechal and was also smoother running, and I had many fine runs in it. I have found Amilcars in general very reliable if the engine speed is kept down. Mr. Vernon Balls—who achieved so many racing successes with these cars—quotes 3,500 r.p.m. as the safe useful limit. Even then they will still show the average small sports-car the way home.
Eventually the Senechal shed a wheel at speed and wrote itself off completely—and nearly me as well. [We believe the solid axle broke and, without being stodgily pessimistic, vintage-cultists might well regard this as a warning.—Ed.]
When I had recovered, my next venture was in 1930 Grand Prix Salmson and I have never been more satisfied. This particular example had three roller bearings to support its beautifully made crankshaft, tubular connecting rods, and twin overhead camshafts.
The gearbox boasted four speeds and the back axle, which lacked a differential, was extremely sturdily made and never gave any trouble. Rudge knock-on wheels were a big improvement over those of Salmson type, which are rather apt to loosen under stress. The maximum speed on the high top gear of 4 to I was only 70 (3,500 r.p.m.), but with a favouring wind or a slight down grade quite a bit more was forthcoming. Like all high-geared cars she could cruise very near to her maximum, and an effortless 60 m.p.h. could be kept up for hours. If a gradient intervened this speed could be held in third gear, using 4,200 r.p.m.
Second gear gave about 50 m.p.h. at 5,000 r.p.m., and I really believe I could have got 60 on this ratio as well, if I had gone up to the full 6,000 r.p.m. available. Since these engines are very rare, prudence counselled restraint. Road holding was very fine, and the car could be flung round corners; it always pointed its front wheels in the right direction no matter what the rest of the chassis might choose to do.
Petrol consumption was 35 m.p.g., and oil 2,000 m.p.g., and the water level never dropped. I was never let down on the road—a most satisfactory motor car, in fact. After the war, if I can get another car with so much reliability and charm as the “Sammie” I shall be well satisfied. Reverting for a moment to Amilcars, I have seen several references in recent issues to that fine little car—now out of production. In most of them the comments passed were not altogether complimentary, and while I quite realise they were the personal experiences of the persons concerned, yet I feel that they were in many cases rather unfair.
In one case the main complaint was a tendency to break crankshafts; and yet the crankshafts were quite reliable if the engines weren’t over-revved. This little unit had an unlimited capacity for high r.p.m. and the two-bearing crankshaft wouldn’t take all that the cylinders could produce. Quite where all the power came from is something of a mystery since the valves were side-by-side and the valve timing not exceptional. Perhaps by some lucky chance the designer got his inlet manifold and valve proportions just right—in an era when these little niceties were not as well known as they are now—and of course the extreme rigidity of the crankcase helps to keep the engine smooth; in fact, this is an outstanding feature of these cars. I have never known a smoother four-cylinder.
Another point that gave cause for complaint was the brakes. These were a cause of trouble when worn-out, but not otherwise. They were rather small in size for the speed of the car, but in the later cars, 1927 onwards, the drum size was increased and they were then very good indeed. In this year also the width of the front axle was increased and the chassis line lowered, which even further increased the road-ability.
On the credit side one must count 70 m.p.h., really good acceleration, and splendid hill-climbing. The whole car was very light and simple and yet it had one of the best-designed chassis frames of any small sports-car. One really weak point was the transmission, which was likely to give trouble, but providing the clutch was gently engaged and the car got moving, then the gas could be turned on in safety—and one certainly knew it. The later models had four-speed gearboxes and heavier bodies, but they still gave an extremely good performance. No one—not even a rabid Amilcar enthusiast—would claim that the marque had no failings, but on the other hand, they were fine little cars in their day, and even now retain a very fair performance if kept in condition.