A tale of two Renaults
Two Renault 5's came up for test last month, the sporting TS and the newly-introduced…
Answer to a road tester’s prayer
Anyone who has ever read a reasonable selection of reports covering Alfa Romeo’s FWD Alfasud will have experienced the impression of, “a very nice small car, perhaps the best of the breed ever produced, but lacks torque”. It seems there is little else to criticise the car for in road-test use and I am supported in this by a 19,000-mile report of a Standard House Ti, which rests alongside my notes of the 1600. Paintwork does appear to have been a problem, but it is said that Alfa have improved the standard since manufacturing our early 1975 car.
Even in Ti form, when there is a claimed 68 b.h.p. to mate with that effective change offered by the five-speed gearbox, the cry is for more power. There is now a 1,300 c.c. coupe in Italy (due to appear in Britain next year) but one does wonder whether the extra 120 c.c. offered is really the answer. Gordon Allen, whose work upon specialist steel crankshafts we featured in 1974, thinks not, and backed up his thinking by inviting us down to his premises at 271 Argyll Avenue, Slough Trading Estate, Slough, Bucks. (Slough 23782), to drive the result of his experiments.
There we found his 1,582 c.c. red Alfasud with four-speed gear knob and five forward gears! From a reputation viewpoint Alfa Romeo should be grateful that it was Allen who decided to enlarge their flat four-cylinder, for there are others of far less competence who play with the baby Alfa Romeo, to the detriment of its noise levels and ease of driving. What Mr. Allen really has in mind is to find a dealer to market the Allen 1600 Sud, but he has encountered little commercial interest in the project, as yet. So customers may be lucky and have Gordon assemble and sell the complete cars, even though he wouldn’t really have the capacity to do many such conversions, for his business is really making crankshafts, not building engines.
Because the Alfasud has such a fine chassis and good four-wheel disc braking, the engine can become virtually the sole target for improvement. Work started on the basis that someone like Blydenstein would be as interested in the Alfasud project as Blydenstein was in the 1500 Vauxhall Chevette, which is now available: incidentally the two cars weigh in at very similar figures.
The Sud we tried had an 83.5 mm. bore combined with a 72.6 mm. stroke (familiar Ford figures) but the bottom end clearances are extremely tight at this figure, so the next batch of crankshafts will allow 1,590 c.c. from a bore and stroke of 85 mm. by 70 mm. Allen says of the crankshaft, “the basic Alfa design is a beauty, short, strong and with only three bearings, so our nitrided version has the stiffness to allow the shaft to resist the sort of r.p.m. that development cars are liable to encounter!”
Pistons, forged by Cosworth and machined by Allen, are notable for their low crowns, a 9.2-to-1 c.r. and a 2 1/2 oz. per piston weight saving over the standard items. It has been a headache to find a piston compact enough to operate within the Sud’s stubby block and Allen is expecting to try some German pistons as well.
While the connecting rods are production parts, each overhead camshaft is profiled along the same timing as Allen uses for modified Lotus-Ford Twin Cam engines.
Carburation on the test car was via a pair of 30 mm. choke Weber DCN twin-choke units, simply linked over the crankcase via an adaptation of the normal system. In detail the carburation is excellent with a two-piece alloy manifold on each side (including water takeoff cast integrally) and a superb plenum chamber, simply fabricated from 18-gauge steel, and stretching across the engine bay to cover both carburetter mouths. A production air cleaner is used as well, and the net result has been to retain the normal Sud’s civilised noise levels, with none of that Weber “blat” to spoil one’s cruising pace. It is expected that Allen will develop a single, twin-choke carburetter as well, offering most of the performance we enjoyed, but saving both fuel and initial costs.
At first sight the car didn’t look very promising. The gear-change has been hammered to the point where second has to be consciously engaged and the clutch has to be carefully released to avoid any slip. The provision of 110/115 shaft horsepower (at 5,500 r.p.m.) and that extra torque needs matching by a bigger, eight-inch diameter, clutch plate. How much extra torque? On a rolling road the Allen car displays 77 lb. ft. at 3,500 r.p.m. while a standard Ti, on the same bed, revealed 51 lb. ft. at 4,000. The Allen Alfa has over 70 lb. ft. torque from this point to 6,000 r.p.m. The same comparison, on a horsepower basis, shows that the Allen 1600 has 28 b.h.p. more than a normal Ti.
Figures and forebodings about reliability were forgotten as soon as one joined in the flow of normal traffic. Response to the throttle was crisp and positive, as it should be with only 161 cwt for 1.6-litres of mddified engine to pull.
As with all the best conversions, this one feels just as if the manufacturer had done the work. Idling is a quiet 500 r.p.m., there are no stumbles in the carburation, and there’s no murderous exhaust rasp to draw unwelcome attention to the car’s astonishing capabilities.
I covered a 120-mile country loop in the morning, then brought the car into London and back to check on the extra flexibility offered. Over the country going it was a great credit to Alfa Romeo, in that their basic engineering proved adequate for the demands placed on the Sud in a new role as a 1600 flier. The blessing of small exterior dimensions, and the car’s excellent handling and braking qualities, take us into a new era of small-car cross-country performance. The 1600 Alfa-sud is as significantly advanced over the Mini-Cooper S as that worthy Issigonis box was over the Ford Prefect.
From 3,000 r.p.m. onward — I used 7,000 r.p.m. in the first two gears and the usual 6,000 or so for 3rd and 4th—the car accelerates determinedly. Keeping it in top down to 1,000 r.p.m. proved feasible, and the car would pull away without disgracing itself with any belching in the carburation. Used very fiercely into downhill T-junctions, I found the engine would stall, but under all other circumstances the engine ran like our proverbial feathered friend.
I decided to write about Allen’s car on such short acquaintance because it was obviously a hard-worked development machine that may not be free for conventional performance testing, and because the performance was delivered in such an unfussy manner that anyone could enjoy the car. Those who insist on a substantial increase in top speed could find fault; for the Sud simply seems to hold the r.p.m. limit in top gear (108 m.p.h.) rather than exceed this point, but I still thought the performance between 40-95 m.p.h. more than adequate compensation. Naturally a price is extracted for such a combination of docility and speed. Utilising the twin carburetter layout with pump jets erring deliberately to the rich side will result in 19.12 m.p.g. with really forceful driving along winding lanes. As .compensation there is the more normal 23.7 m.p.g. for a brisk main and B road crosscountry trip, or an interesting 23.5 m.p.g. when cruised at an indicated 100 m.p.h. with the throttle eased as far back as possible: at 65 m.p.h. and 4,500 r.p.m. the throttle is just cracked open to maintain the pace.
How much is it all going to cost? That must depend on the quantities finally produced, but the car I enjoyed represented £225 for the new crankshaft; £100 for pistons; £175 for the carburation, linkages, and manifolding, plus £100 for labour. The top speed problem could be alleviated by production of a larger bore exhaust system, top to tailpipe, but Gordon Allen is naturally anxious to retain the quietness of the normal system used at present, so the exhaust, and the alternative single-choke carburation are the priorities Allen will follow on what is already a first-class piece of engineering. We will watch for further developments with interest.—J.W.
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