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[mab01uk]

Motorsport magazine Page 9, August 1963
On test with a Nerus modified Austin Mini

As far as sporting enthusiasts are concerned the ordinary Mini has far less attraction than the Mini-Cooper and its latest S-type derivation. However, the standard Mini costs only £448 while the Mini-Cooper costs £568 and the S-type is £695. Of course, there are several advantages to be had in the Cooper models such as the improved engine and gearbox and remote control gear-lever but the front disc brakes have rather dubious merit and really need the servo assistance supplied in the S-type. As the rest of the car is virtually the same, anyone wishing for the outstanding handling of the Mini would be well advised to save over £100 and buy an ordinary Mini and be prepared to put up with the lower performance. An intensive course in double de-clutching would also be of great assistance.

Having saved the £120 over the Cooper-Mini the enthusiast will find that the performance needs ameliorating and of course it is quite possible to spend much more than £120 in the fitting of tuning equipment. This is where the Nerus Engineering Company comes into the picture for they are specialists in providing modest increases in performance at a modest price and with only a slight increase in fuel consumption.

Nerus is an offshoot of the long established Rother Ironworks which has been producing high quality castings for over a century. The man in charge of the Nerus works at Rye is Frank Webb whose experience includes several years in the experimental department of Lagonda, a spell in charge of the H.W.M. Formula Two racing team and more important as far as Mini tuning is concerned a number of years spent as chief assistant to Harry Weslake who is one of the World's leading authorities on cylinder head design.

Naturally with such a background the emphasis of Nerus tuning is placed on cylinder head modifications and the Rye workshops are equipped with modem gas flow plant and Heenan and Froude dynamometers. Three different stages of cylinder head modifications arc offered by Nerus for all cars and these are sold on an exchange basis, the prices ranging from £17 15s. 0d. to £34 5s. 0d. Normally Nerus supply only cylinder heads and make recommendations for other equipment to improve performance still further, although for the Mini they do supply modified camshafts.

Stage I for the Mini has the inlet and exhaust ports modified and polished, the combustion chambers modified and polished to improve turbulence and burning characteristics and the combustion chamber volumes are balanced to improve smoothness and torque. The valve spring assembly is strengthened to allow the engine to reach 6,200 r.p.m. in the gears. This head gives a modest increase in performance but Nerus claim that if the car is driven normally the fuel consumption will improve. This stage costs £17 15s. 0d. on exchange.

Stage II follows a similar pattern to Stage I but the compression ratio is raised from 8.3 : 1 to 8.8 : 1, larger inlet valves are fitted and stronger valve springs supplied so that 7,000 r.p.m. can be reached. This head is particularly suitable for the fitting of twin carburetters, high-lift camshafts and modified exhaust systems and costs £21 15s. on exchange.

Stage Ill is the most advanced head and is intended for use where high speeds are envisaged or where competition work is planned. This head is the same as the Stage II version with the larger inlet valves. Larger exhaust valves are fitted in conjunction with double valve springs and considerably more work is carried out on the ports and combustion chambers while the compression ratio is raised to 9.0 : 1. This head, which costs £30, is mainly intended to be fitted in conjunction with twin carburetters, modified camshaft and tuned exhaust systems as this is the only way to realise the full potential of the gas flowing operations. With the modifications recommended by Nerus 72 b.h.p. can be obtained or on the Mini-Cooper engine 83 b.h.p. at 7,200 r.p.m. can be achieved. Nerus offer three different camshaft grinds for the Mini; one is for normal road use, the intermediate one is for a car which is to be driven on road and track, and the racing shaft can only be fitted in conjunction with the steel racing crankshaft. As this allows the engine to develop peak torque at between 5,500 and 6,000 r.p.m. it is not suitable for road use. These camshafts cost £8, £9 10s, and £11 10s. respectively on exchange.

Recently, Nerus loaned us for road-test a standard Mini with the Stage III cylinder head which retained the single S.U. carburetter with a richer needle, slightly cleaned up inlet and exhaust manifolds and a straight-through silencer. Together with a special cylinder head gasket the whole conversion costs £35 3s. 3d. In all other respects the Mini was standard except for the Nerus badge on the boot lid, and in fact the car had covered 27,000 miles at the start of our test as the car is used as normal day-to-day transport by Nerus.

When driving the car the most noticeable difference is the way the engine goes on revving way past the point where the standard Mini has run into valve bounce and although no rev. counter was fitted it would seem from the performance figures that 6,500 r.p.m. is reached quite comfortably, and no doubt when the twin carburetter conversion and sports camshaft are fitted the engine will comfortably exceed 7,000 r.p.m. Some vibration is felt at peak revs and is transmitted through the gear-lever. The only other sign that the engine is tuned is indicated by the exhaust system which has a normal note at speeds up to about 2,000 r.p.m. and takes on a delightful crackle from then on. It is also noticeable on the over-run but does not become objectionable.

As the data table shows the performance is considerably better than the standard Mini, especially up to 60 m.p.h., but above this speed it tends to run out of breath and this is where an extra carburetter would show to advantage. However, it will almost touch 70 m.p.h. in 3rd and goes on to a maximum of 80 m.p.h., which is 8 m.p.h. better than the normal Mini. A cruising speed of 70 m.p.h. is quite comfortable although the usual high noise level of the Mini is present. The tractability of the Nerus Mini is only fractionally worse than the normal Mini and does not become apparent unless the driver lets the car lug down to very low speeds. The gearbox of the test car still had good synchromesh after 27,000 miles but the change is still extremely poor by modern standards. A feature of the car which was showing signs of old age were the shock-absorbers, which allowed a great deal of fore and aft pitching on bumpy roads as well as lateral pitching on corners. Obviously the Mini rubber cones cannot do all the work without the aid of shock-absorbers. The brakes were quite up to the performance and showed no signs of fade when stopping the car from high speeds. Nerus recommend fitting a hard lining with their conversion and will fit a complete set for just over £8.

This £35 conversion seems to be good value as even in the form tested it provides much improved acceleration and top speed without worsening the fuel consumption to any great extent. It has the advantage that the conversion can be added to at any date and the addition of a second carburetter and a modified inlet and exhaust system should take the performance well over that a Mini-Cooper for the expenditure of around £50. —M. L. T.

Acceleration figures

Standard Mini-Minor - Standard Mini-Cooper - Stage III Nerus Mini-Minor
0-30 m.p.h.: 7.0 sec. - 5.2 sec. - 5.4 sec.
0-40 m.p.h.: 10.6 sec. - 7.4 sec. - 8.4 sec.
0-50 m.p.h.: 17.5 sec. - 11.0 sec. - 13.0 sec.
0-60 m.p.h.: 27.6 sec. - 17.1 sec. - 20.0 sec.
0-70 m.p.h.: — - 28.0 sec. - —
Standing-start 1/4-mile: 23.5 sec. - 20.5 sec. - 21.3 sec.

Speeds in gears
1st: 25 m.p.h. - 30 m.p.h. - 28 m.p.h.
2nd: 40 m.p.h. - 50 m.p.h. - 43 m.p.h.
3rd: 60 m.p.h. - 70 m.p.h. - 69 m.p.h.
4th: 72 m.p.h. - 85 m.p.h. - 80 m.p.h.
Overall fuel consumption: 44.0 m.p.g. - 36.1 m.p.g. - 36.6 m.p.g.

Nerus Stage III cylinder head: £30 0s. 0d.
Modified induction & exhaust manifold: £1 10s. 0d.
Carburetter needle: 3s. 9d.
Silencer: £1 7s. 6d.
Cylinder head gasket: £2 2s. 0d.
Total: £35 3s. 3d.

Fitting extra: £7 0s. 0d.
https://www.motorspo...ied-austin-mini

 

[mab01uk]

Motorsport magazine, Page 56, July 1964
A Speedwell Modified Mini

Speedwell are better known for their extensive conversions to B.M.C. cars, such as the 110-m.p.h. Riley Elf we tried a few months ago, but the bulk of their business is in milder conversions, giving that little bit extra steam to the slower cars in the B.M.C. range. A popular conversion for the normal 850 Mini is one which brings the performance up to Cooper Mini standards, and we have recently been trying a de luxe Mini, perfectly standard except for the addition of the Speedwell Grand Touring engine kit. This kit consists of the Speedwell alloy cylinder head plus a twin carburetter layout and a Speedwell twin-pipe silencer. The alloy head, the patterns for which had to be made in Italy, is sold in two forms, the GT for the less powerful B.M.C. engines and the Clubman for the more powerful units. The GT head which was fitted to our test car uses standard-sized valves and single springs, and has a 10.5-to-1 compression-ratio, whereas the Clubman has larger valves, a different combustion chamber shape and a compression ratio of 11 to 1, which can be raised to 13 to 1 for racing purposes.

The three carburetter kits which are available with the alloy head are twin S.U. HS2, twin Amal, or single downdraught Weber with double chokes. The test car was fitted with the Amals, which give more performance than either the S.U.s or the Weber but have some idiosyncrasies which might deter some people from using them for road driving. The complete kit of cylinder head, carburetters, silencer, chromed rocker cover, spark plugs and all the necessary gaskets and so on costs a total of £70. The S.U. kit is cheaper at £65, and the Weber kit costs £72. The cylinder head can be purchased separately for £39 10s., and the carburetter and silencer kits can also be bought separately: £27 for the S.U., £33 for the Amal, and £35 for the Weber kit.

The test car was a normal de luxe Mini with about 6,000 miles on the speedometer and was standard except for the addition of the Speedwell kit, a Kenlowe fan, costing £12 15s., and stiffer shock-absorbers. The only unusual control for the driver to worry about was a motorcycle-type choke lever which was attached to the parcels shelf. The starting procedure with the Amals can be tricky but once the technique is learned, first-time starts can be made without trouble. With the engine cold it is necessary to have the mixture control at fully rich and then depress the accelerator when the starter is operated. The engine usually fires first time and then the mixture control must be closed fairly quickly to prevent stalling. In extreme cold weather it may be necessary to flood the carburetters by "tickling" the button on the float chambers, but the engine always started well with us without resorting to this technique. To start the engine when warm it is necessary to "catch" the engine by depressing the throttle just after the starter begins to turn.

According to Speedwell the advantages of the Amal carburetters, which are more normally used on motorcycles, is in their ability to hold their tune over long periods, although they can be difficult to tune initially. S.U. carburetters are easier to tune but tend to lose their tune quicker.

On the road the increased performance was immediately evident and the Mini charged along in an impressive way. Later on, the stop-watch confirmed that this car's performance was well up to Mini-Cooper standards despite its less advantageous gear ratios, which leave it with a bigger gap between 2nd and 3rd gears, thus affecting the 50-m.p.h. time especially. As the attached table shows, the Speedwell car is slower to 50 m.p.h. than a Mini-Cooper because of the extra gear-change involved, but by the time 60 m.p.h. is reached it has more than picked up the lost time. It is also quicker to 70 m.p.h. than the Cooper, and on the standing-start 1/4-mile it is half a second quicker.

There is some loss of flexibility with the Amal layout and it is necessary to use the gears to get the best results, which is, of course, no hardship to the keen driver. If the throttle is opened wide at low r.p.m. in the higher gears there is a bad flat spot, but the person who lugs around in top gear will hardly be in the market for a Speedwell conversion, and in any case for the driver who wants a little more flexibility the S.U. and Weber layouts are available.

Due to the better thermal efficiency of the alloy head the Mini would run quite happily on 90-octane fuel but we used 97 or 100-octane during our test and obtained a fuel consumption of 32 m.p.g., despite a leak from one of the carburetters. Speedwell claim 34 m.p.g. and this does not seem at all unreasonable. The Supertone silencer does not raise the noise level appreciably, and in fact the exhaust note is most pleasant. Fitted to a Mini-Super de luxe which costs £493 the Speedwell conversion brings the price up almost to that of a Cooper Mini; fitted to the normal Mini at £448 there is quite a considerable saving. Many people prefer the drum brakes of the ordinary Mini over the discs of the Cooper range, and the standard Mini gearbox is a vast improvement over the wretched device inflicted on early Mini drivers. Another advantage of the Speedwell conversion is that the alloy head and attendant carburetters, etc„ can be transferred to a new car and the standard cylinder head and carburetter replaced when selling the car.
https://www.motorspo...l-modified-mini

[mab01uk]

Motorsport magazine, Page 54, December 1963
Road test—driving a 107 m.p.h. Riley Elf

Every so often we test a modified car which offers fantastic performance for its capacity. Such a car is the Speedwell-modified Riley Elf which we have been testing recently. Although on the face of it the Elf is one of the least likely of the Mini range to benefit from tuning treatment, Speedwell decided to market the car as the "Executive Riley," aimed at the man who wants outstanding performance but also prefers the better appointments and slightly larger boot of the Elf. This particular car is only offered as a complete package and costs £825, although of course anyone who already owns an Elf could have much of the work done by Speedwell, but it would probably be more expensive.

Most of the cost of the conversion goes on the engine, for this is modified from its standard power output of 38 b.h.p. at 5,250 r.p.m. to give no less than 93 b.h.p. at 7,400 r.p.m. This necessitates stripping the engine, balancing the rotating parts, increasing the engine capacity from 998 c.c. to 1,150 c.c., fitting the Speedwell aluminium cylinder head with 11-to-1 compression ratio, twin S.U. carburetters, high-lift camshaft and so on. This is only about 5 b.h.p. less than Speedwell's Formula Junior engine specification, the absolute maximum top-end power being sacrificed for better torque lower down the rev. range. It actually produces 78 lb. ft. of torque at 5,500 r.p.m., against 52 lb. ft. at 2,700 r.p.m. of the standard Elf.

This power results in the most fantastic performance on the road for the Speedwell Elf will accelerate cleanly up to 7,500 r.p.m. in the lower gears, but for performance testing we contented ourselves with using 7,000 r.p.m. as a gear-change point. An extra on the test car, costing £17 10s., was an electronic rev.-counter made for Speedwell by Weston's which has a single slim red line marked at 7,500 r.p.m. So easily did the engine rev. to this figure in 1st and 2nd that we would recommend the rev.-counter as a safety factor to avoid over-revving. Due to the large amount of wood in the Elf facia panel the rev.-counter had to be fitted in the lid of the glove locker in front of the driver, which might upset the lovers of wooden facias, but otherwise a special bracket would have to be made up. At 7,000 r.p.m. in the gears the Elf gives speeds of 29, 49, 75 and 104 m.p.h. In fact when testing for maximum speed we found that the Elf would achieve 7,200 r.p.m. on the flat in top gear, a speed of 107 m.p.h., but this took a long while to come up, and only on a long downgrade could 7,500 r.p.m. or 112 m.p.h. be seen. However, its maximum speed is not so important as its ability to cruise along at 6,000 r.p.m. in top (90 m.p.h) for hour after hour if need be and still have some acceleration in hand to pass the odd Bentley or Jaguar. Perhaps the most pleasant aspect of driving the .Speedwell Elf is to study the expressions on drivers' faces as the Elf goes past. These range from downright anger to incredulity, and from those with a sense of humour, amusement. A few drivers speed up to try and stay with the Elf but few keep up the pace for very long. The test car was fitted with a headlamp flasher, costing 18s. 6d., which is a worthwhile investment as the Elf passes a lot of cars and the lights need to be flashed quite a lot. The hooter is the standard one, which is not very effective.

Having had experience of other highly-tuned B.M.C. engines we expected the Speedwell unit to be temperamental, and the sight of a spare set of plugs in the door pocket did nothing to reassure us. However, this engine proved to be very tractable and gave no trouble at all. In heavy traffic it would fluff occasionally but a blip on the throttle always cleared the plug immediately. The oil pressure stayed between 50 and 75 p.s.i. according to road speed, and the needle of the water-temperature gauge seldom moved more than halfway across the dial, always staying in the " normal" position. The engine had a "lumpy" idle but never stalled and was certainly no noisier than most standard Mini engines. If the throttle was depressed too rapidly a smell of petrol invaded the car but this could be avoided quite easily. The carburetters of the test car had no air cleaners, which no doubt aggravated the problem.

It could not be expected that the Speedwell Elf would be as tractable as the standard version but it will trickle along at 30 m.p.h. in top gear and accelerate away quite cleanly, although with the performance available in 2nd gear there is little point in doing this. The Elf is of course a superb car for traffic driving as it can be flicked in and out of the traffic and has the acceleration available to get the driver out of trouble in many situations. The performance figures in the data table show just how quick the Speedwell Elf is, compared with some other fast cars, but even these figures could be bettered by a considerable amount as we had to take the figures on a soaking-wet track. The car was fitted with the standard C41 Dunlop tyres and violent wheelspin occurred all the time in 1st gear. By letting in the clutch at 3,000 r.p.m. in 1st the car just stood still while the rev.-counter whistled round the dial, and it was only by dropping to 2,000 r.p.m. that we were able to get the car moving at all. In dry conditions with Dunlop SP tyres it should be possible to knock 2 sec. off most of the figures above 50 m.p.h. In any case a figure of 12.4 sec. for 0-60 m.p.h. will still manage to dispose of most other vehicles.

With this sort of performance the brakes of the Elf obviously needed modification and the Executive Riley is fitted with hard competition linings and a vacuum brake servo as standard equipment. The pedal pressure required is quite high for power-assisted brakes but the Elf pulls up well with no sign of fade from high speeds and there is none of the snatch or squeal sometimes associated with hard linings.

The handling of the Mini range is too well known to require detailed discussion but the Speedwell Elf differed from standard in having a rear anti-roll bar costing £7. It is difficult to evaluate the results imparted by the roll bar as the whole of our test was conducted on wet roads and the C41 tyres proved inadequate for high-speed cornering in the wet, so that we were unable to explore the limits of the Elf's road-holding. In addition the shock-absorbers gradually weakened during our test until at the end they were almost totally out of action, having covered only 3,000 miles from new. In conditions like these one begins to appreciate the hard work done by shock-absorbers for without them the Elf floated about like an American car and was almost uncontrollable on bumpy roads.

The test car also had a couple of other interesting extras which added to our enjoyment of the test car. These were a Golde sunshine roof costing £60 and a pair of RestaII de luxe reclining front seats costing £25 each. The sunshine roof, fitted by the Allard Motor Co., is released by a roof handle and then slid backwards. A transparent plastic wind break can then be swung upwards to deflect air over the top of the car. The P.V.C. covering of the sunshine roof was finished in white to match the white roof. We regret that the weather during the test precluded its use for more than a few minutes but at least we were able to discover that it was completely waterproof.

The Restall seats are not of the bucket type, but with deep foam cushions and reclining backrests they proved to be much more comfortable than the standard Mini seats, which are decidedly uncomfortable. The backrest is lowered by means of a large knurled wheel which is rather difficult to turn and the fully reclining position cannot be reached owing to the proximity of the rear bench seat.

This Speedwell Elf shows that a highly-modified car need not be intractable, noisy or uncomfortable, and we can see this car appealing to many other people as well as "Executives." As well as its 100-m.p.h. plus performance the Elf has a remarkably good fuel consumption, our overall average working out at 32.8 m.p.h., although the small 5 1/2-gallon tank means that the range is not much over 170 miles. £825 is a lot of money for a car which costs £575 in standard form but we can see many people placing orders for the "Executive Riley."—M. L. T.
https://www.motorspo...63/54/road-test
 

Edited by mab01uk, 08 June 2019 - 10:00 AM.