Two magnums
Two Magnums not of champagne, but Vauxhalls. The long-established and famous name of Vauxhall has been back in the ascendant for some time, with the excellent Chevette, Cavalier, and the up-lifted VX models. The ageing Magnum has also had a technical face-lift. As an 8 ft. 1 in. wheelbase saloon weighing around the ton at the kerb, this Vauxhall model can be regarded as a sporting saloon from the noted General Motors’ Luton factory, and therefore justifies inclusion in Motor Sport.
Derek Goatman made available to me first the Magnum 1800. Colleagues who saw it in the Office car-park and knew I had recently been driving cars of BMW calibre looked rather sideways at me, thinking I had perhaps made an unfortunate choice. I thought that myself. But I hadn’t long thrust this Magnum 1800 through the London home-going traffic before I found I was favourably surprised. It has definite poke, allied to a good top-gear performance. Indeed, after a varied and unsparing 1,250 miles of this heady motoring I asked for a 2300 version, for impressive as the compact 1800 was, a 2.3-litre should obviously be more so. Again, Derek Goatman went to some pains to let me test both Magnum models consecutively, having a 2300 brought down specially from Ellesmere Port.
The 1800 first,then. It has been uprated enginewise to the extent of now developing 88 (DIN) b.h.p. at 5,800 r.p.m., with a single Stromberg carburetter and a c.r. of 8.5 to 1, which is an improvement of 11 b.h.p. for an r.p.m. increase of only 600. That is from the single-overhead camshaft 85.73 x 76.2 mm. four-cylinder engine, inclined in the HC Viva frame and its camshaft belt-driven.
To a degree the Vauxhall Magnum has dated and thus I found it became frisky over rough going. But there was no mistaking its spirit; I had to rein it in on our 70 m.p.h. Motorways. Top pace, in fact, exceeds too m.p.h. and it will devour a ss 1/4-mile in less than 19 seconds. There is quite good rack-and-pinion steering, geared at 3 1/2 turn, lock-to-lock, with a sensibly small, leather-rimmed steering wheel. The brakes are servo disc/drum. The appearance of the Magnum is rendered distinctive by the old raised-vee along the bonnet-top and by the use of Rostyle wheels, shod on the test cars with Vauxhall’s discerning preference for Michelin tyres. In this Magnum you get a 12-gallon fuel tank, very reasonably comfortable, cloth-covered seats, four halogen headlamps (with rather too downset beams) and plenty of instrumentation. The last-named consists of speedometer, tachometer, oil-gauge (normally reading just above 40 lb./sq. in.), a big clock, battery meter, water thermometer and fuel gauge. Six warning lights are neatly grouped in a vertical .cluster to the left of the instrument panel, the top window telling the driver he is on headlamps, full-beam, but dazzling him at night. The extremities of the facia are given over to gimball air-vents that do not function if the fan is used but which otherwise give a good draught. There is an unlockable cubby before the front passenger. Also underfacia shelves and a very shallow tray on the console, presumably for visiting cards.
That individuality isn’t dead is seen in the placing of the lamps-switch and backwindow-demister-switch down on the central console (the only possible disadvantage being that tiny hands might just switch off the lights at an awkward moment) and in the figures on the tachometer being at the base of the dial, whereas those of the speedometer are arranged conventionally. A contemporary explains that this is to prevent one’s right hand on the steering wheel from blanking the reading, but elsewhere calls this “a silly nonsense”. It seems logical to me, but untidy.
Two stalks control the usual services, with a horn button on the rh one and the gear lever, controlling a notch y change, has a lift-up catch to guard reverse-gear position. The central hand brake is well placed but on both cars needed a firm pull to hold the car on a gradient. The doors the 1800 I borrowed was a two-door saloon but a four-door model is available worked rather “graunchily” and needed a slam to shut them but before one criticises this and the lack of a vanity mirror (as the ladies do) or coathooks, let me remind you that this Magnum 1800 sells for only £2,738. Although it is so pleasantly lively it is quite high-geared, the engine running at less than 4,000 r.p.m. at 70 mph., which probably explains why I got 34 m.p.g. of 4-star fuel in normal motoring. The automatic choke works impeccably and there is only the faintest indication of second-choke change-over when accelerating.
The suspension is lurchy and very lively, there are a good many body noises over rough roads, and handling is only average. The body is also better for two grown-ups and two or three children than as a full four-seater, but the self-locking boot is capacious. It is illuminated without recourse to the lamps’ switch, by the way. There is the added advantage of Vauxhall under-sealing against the demon rust and this modest Magnum comes in some nice colours. It is a useful, competitively-priced car, improved effectively by the enhanced power and the bigger (175 SRX 13) radial tyres.
The Magnum 2300 for which I exchanged the 1800 model at Luton, where the executive offices are largely unchanged since the dignified days when the 23/60 and 30/98 Vauxhalls were new cars, was a four-door saloon, again in a nice shade of metallic Amber Gold. It is almost identical to the 1800 in detail, except that the back-window-demister switch is on the facia, this console switch being blanked off, although its symbol remained. Vauxhall, by the way, use very clear symbols on controls and warning lights. The bigger-engined car also has a lockable, bayonet fuel-filler, the key of which was stubborn. The best part of this 2300 Magnum is its engine. Marked on the tachometer with a rev-limit commencing at 6,200 r.p.m., it will cruise the car all day at an indicated 100 m.p.h., running at a mere 5,200 r.p.m. Driven like that it consumes 4-star petrol at the rate of around 24 m.p.g. I obtained 28.7 m.p.g., including much Motorway driving, in this country. The gearing is higher than on the 1800, so that 70 m.p.h. equals fractionally over 3,700 r.p.m. (Vauxhall speedometers read “fast” an indicated 70 on the 1800 was nearer a true 65 m.p.h. and 5,200 r.p.m. on the 2300 represents an actual speed of just under 98 1/2 m.p.h.).
The big engine, developing 108 (DIN) b.h.p. at 5,000 r.p.m. in this comparatively light car (2,304 lb.),pays off, in acceleration and effortless running in top gear, up to some 105 m.p.h. or more. It isn’t possible to pull away smoothly from 1,000 r.p.m. in the highest gear. But the engine smooths out before it reaches a mere, 1,500 r.p.m. At speed, it has so much in hand, before that 6,200 r.p.m. limit comes up. However, it isn’t a particularly quiet power unit, being too noisy at 70 m.p.h. and the test car had a bad rattle on the over-run, presumably from the exhaust system, which became much worse as the mileage increased. (The reading showed over 9,000 miles before the test commenced, though.) The gear change has the same well-angled lever but is as notchy as that of the 1800, with, into the bargain, very bad baulking from 3rd into 2nd gear. On dry roads the handling is acceptable. But the lurch, lively, coilspring suspension didn’t give all that much confidence, although a sense of over-softness which had in on fast corners on the 1800 wasn’t present in the Magnum 2300.
Whereas the 1800 had used no oil in 1,250 miles, as the awkwardly-buried dipstick showed after the heavy bonnet had been raised (the catch-release is on the n/s, under the passenger’s oddments shelf) and propped open, the 2300 consumed lubricant at the rate of approximately 900 m.p.p. The 2300 engine feels somewhat rough but quite unburstable.
In both these cars you have the advantages of reasonable-sized engines in compact body shells, and even the four-door 2300 is priced at only £2,971.80. So it seems that, with Chevette success in rallying, the racing activities of Team Vauxhall, Blydenstein tuning, the Luton Company’s concern over rust prevention and good relations with its customers and James Hunt using a Chevette, Vauxhall now has plenty going for it.
W.B.
More fizz from a Chevette and a Cavalier coupe
Increasing demands from, and the success of the dealer team vauxhall racing and rally cars have failed to dampen or restrict Bill Blydenstein’s enthusiasm fpr improving the performance of Vauxhall road cars. While a large section of the Blydenstein/DTV workshops adjacent to Shepreth Station, Hertfordshire, is given over to the preparation of the impressive 16-valve. 2.litre rally Chevettes for Airikkala and Sclater and the Group 1 racing Magnums and VR Firenza for Gerry Marshall, there has been no let-up in development to prove Blydenstein’s theories that the tour-cylinder Vauxhalls of all descriptions; even those, with Opel engines, can he made to provide the ultimate in road-going performance arid efficiency.
Long experience with Blydenstein’s modified cars has convinced me that Blydenstein’s theories can he put very effectively into practice. There have been hiccups in the convictions, however: a Victor which had won the caravan raging ,championship without missing a beat contrived to break 10:0 differentials on the trot whilst being tested (but consequently not written about) by me for Motor Sport. A Chevette to which a DTV Sportspart outlet had attached a Blydenstein bolt-on carburetter kit proved to be a distressingly noisy, unreliable means of transport to an important meeting with Leyland executives in the Midlands. It too was sent back with its tail between Its legs.
Perhaps because of my strong feelings about that Chevette together with an inference that I didn’t know what I was talking about anyway. I was bypassed in favour of the Editor with an oiler to test a bored and stroked 1,500-c.c. Blydenstein Chevette. Unfortunately W.B. failed to take advantage of the offer, because by all accounts that little Luton tool was a real flier, with bags of torque and remarkable fuel economy into the bargain. That very engine, and an identical mate, is being used to great effect by Chris Daisy in rall ying (an outright win in one event) and in autotests, leading its class in the BTRDA Championship.
Time is a great healer, and recently not one, but two. Blydenstein cars came my way, from the top and bottom of the new-look, sportingly droop-snoop range. High standards of production performance have demolished much of the demand for “go faster” equipment on road cars, but the Chevette and the particularly stylish Cavalier Coupe don’t quite have the guts to back up the exceptionally good looks and handling. Bill Blydenstein has set about matching standard Int’ standard, with meaningful effect.
The Blydenstein Chevette
Someone as well versed as Bill Blydenstein in tuning the familiar 1,256 c.c . four-cylinder, push-roil Vauxhall Viva engine might have been expected to find the Chevette a piece of cake to modify for fast road use. Not so! The specification of the road-test hatchback which offered in extra 13 b.h.p. or so at the flywheel, had taken some 18 months to develop. Blydenstein’s major hurdle was the vastly improved efficiency of the standard engine in Chevette guise. Not so many years ago the combination of a modified cylinder head and carburetter kit gave 10 to 15 b.h.p. and instant happiness at the top-end. But in those days the standard Viva HB did only 76 to 78 m.p.h. flat-out. The efficient little standard Chevette will whirl up to 88 to 90 m.p.h. before the Blydenstein administrations.
Improvements to the standard engine in production have come from the introduction of the efficient Stromberg 150 carburetter with hinged needle, from increasing the temperature at which the engine runs and by decreasing the port sizes to get a higher gas velocity. The result is an engine which runs extremely lean yet gives good top-end power output. The effect for Blydenstein has been to make it extremely difficult to improve upon the performance versus fuel consumption parameters for this comparatively heavy little car (the hatchback version ts quoted at. 17 cwt).
Whatever the problems, he has certainly succeeded, his Chevette package being a thoroughly lively little tool which, while no “road-smoker”, has performance which complements already outstanding handling to provide surprisingly rapid and enjoyable transport, with few detractions. A genuine 95 m.p.h. is on tap (at which stage the testcar’s speedometer needle was well above the “ton”) and over three seconds has been shaved off the 0-60 time. But standing-start figures are only half the story, for the real gain is at the top-end and in trip gear performance right through the range. Nearly 4 1/2 sec. is taken off the important 50 to 70 m.p.h. top gear acceleration segment and no less than 10 sec off the 60 to 80 m.p.h. top gear time, a boon for motorway overtaking. Detailed figures are shown below, with those for the standard car in brackets.
The Shepreth tuner intended to keep down the cost of this conversion by retaining standard valve sizes. Experimentation proved such idealism to be unrealistic and the resultant Stage 3 head now offered for sale features inlet valves as large as they will go, almost touching the standard exhaust valves”. The inlet valve throat area is suitably opened out too. The compression ratio is unaltered. A Stromberg 175 carburetter replaces the standard 150 Item, a development carried out jointly with Autotechnique, the Luton-based carburetter specialists run by Brian Page and David Rolt, who do the final setting up of most Blydenstein/DTV carburation. Sparks are assisted by Lumenition electronic ignition, in which Blydenstein is a firm believer.
The modified cylinder head alone gives a 6 to 8 b.h.p. improvement at the flywheel, to which the carburetter adds another 4 b.h.p. The total improvement when installed is 10 b.h.p at the wheels, equivalent to up to 13 b.h.p. at the flywheel. Only a tiny improvement in power, at the top end, is afforded by the Lumenition, but Blydenstein feels that the improvement it gives in smoothness and warm-up is worthwhile.
The test car needed a couple of turns on the key to start on full choke from cold, but the choke could be pushed in after only a few hundred yards. By this point it would run so cleanly that the throttle could be depressed to the floor in top gear at low speed without a hiccup. I didn’t follow up this cold engine ill-treatment by letting the revs rise very far. Quick warm-up was matched by very quick cooling: the choke was needed again after short periods of parking.
Blydenstein admits to the modified car losing some flexibility at low speed. This comparison with the standard car is unjust, for the test car would pull cleanly from 14 m.p.h in top gear with less of that familiar Vauxhall transmission judder than I remember from the standard car, and I wasn’t aware of having to use the gearbox any more than usual in town. Taken across the range there is of course an improvement in flexibility. Apparently the use of the standard carburetor with the modified cylinder head will improve general flexibility still further, at the expense of top-end power.
The only real drawback I could find to the conversion was an increase in noise level, because a sports air cleaner has to be substituted for the standard item, deigned for the standard I in Stromberg. Acceleration was accompanied by a fair amount of induction boom and hiss, which settled down to an almost standard level at cruising speeds. The engine noise was far from intolerable and low wind-noise compensated for some of it.
A deterioration in fuel consumption Blydenstein quotes 10%-is another drawback with the conversion, but almost insignificant on such an inherently economical car. I confess to having upset Bill’s records with a greedy 29 m.p.g., a figure which reflects acceleration testing and some very heavy-footed motoring. My best was 30.34 m.p.g. The more usual average shown in the car’s fuel log book was 33 m.p.g.
The test car impressed with its standard features of excellent handling-albeit with plenty of understeer, partially due, I suspect, to well-scrubbed front tyres-and superb brakes. Nothing had been modified in these departments, which had a hard life of mostly 1,500-cc.-powered motoring behind them. A most attractive front spoiler had been fitted, matching that on the Cavalier Coupe below, which I am told, though could not prove, has a very beneficial effect. A tachometer would have been appreciated.
The cost of the conversion, available through Sport or Vauxhall dealers, is about £300. The Stage 3 head on outright purchase is £154.23 (Part no. DTV 33-877), the Stromberg 175 kit £87.45 (DTV 22-844) and Lumenition ignition is £34.70. Fitting would be about £48, excluding VAT. The parts listed are a very good starting point for more extensive conversions for competition; a modified camshaft added to these will bring a considerable power increase.
The Blydenstein Cavalier Coupe 2200S
The modified Rover 2200 SC badge on the boot-lid gives only part of this very fast Cavalier Coupe’s secrets away. Most people assume that the 2200S signifies a version of Vauxhall’s o.h.c. slant-four has replaced Opel’s 1,897 c.c., vertical, high-camshaft, non-crossflow engine. In fact Blydenstein’s “current pride and joy” has had its Opel engine stretched very expensively to 2,170 c.c.
This capacity has been achieved by taking out the standard 93 mm. bore to 95.25 mm., the easy part, and extending the stroke from 69.8 mm. to 76 mm., the difficult and costly part. Gordon Allen, of Slough, who supplies 1,500-c.c. Chevette crankshafts, has manufactured a special steel crankshaft, nitrided to racing specification, used in conjunction with special short Allen con-rods and 95.25 mm. pistons. The cost of these component parts alone is £750.
Add to this a Stage 2 cylinder head, an as yet experimental four-branch exhaust manifold assembly and Lumenition electronic ignition and the test car’s engine bill alone would be £1,000. In addition this car had also been fitted with a front spoiler made to DTV specifications by Barry Shepherd of Rawlson, Dover. This most attractive item is available through Sport dealers (Sportpart number 76-755) at a cost of £45.95 plus painting and fitting.
The all-in-conversion cost as tested was a massive £.1,080. If that sounds an awful lot to fork out on top of a £3,852 motor car, it should be stressed that the project was intended as an engineering rather than a marketing exercise, as with the 1500 Chevette. However, Blydenstein has already taken an order for delivery in early autumn. The conversion will be made to order only and delivery either of parts or fitting of the entire conversion at Shepreth is quoted as four months.
“We don’t intend to make many of these conversions,” says Blydenstein. “What we want to try to do is to point out to the motor industry in general that big capacity 4-cylinder engines are the “bees-knees” when it comes to superb performance/efficiency, i.e. it is perfectly possibly to achieve 4-litre performance with 2-litre economy!”
He has aimed for massive mid-range performance to create a car capable of accelerating in top gear from 30 to 90 m.p.h. in just over 22 seconds, less than five seconds slower than a V12 E-type. He believes that this Cavalier thus matches the requirements of many drivers in today’s conditions of heavy traffic density and legislation: that maximum speed is no longer of real consequence and that the important factors, so long as the car is capable of an easy 100 m.p.h., are driveability, particularly performance in that top gear 30 to 90 m.p.h. area, overall petrol consumption over a 12 month period and emergency acceleration from 0-60 m.p.h.
The performance figures speak for themselves, the times in brackets being for a standard 1.9-litre Cavalier Coupe tested by Vauxhall Motors:
Fuel consumption suffered from continuous use of the available acceleration, the worst being 23.5 m.p.g. and the best 23.75 m.p.g., neither of which is all that bad when set against the performance. Again the fuel log book (Blydenstein is very meticulous about such things) showed a more usual average of about 25 m.p.g. To be fair, the carburation at the time of the test was not fully sorted and Blydenstein hopes big improvements will come from an exercise to develop an exhaust-heated rather than water-heated inlet manifold. The carburation has had to be enriched to compensate for the latter. In addition, the automatic choke was playing up, letting this big lump of engine, which takes a long time to warm up, run very rich for far too long. There were one or two very slight fiat spots with the engine at working temperature, which should be cured by this further development.
I don’t want to write much about the car itself, because it wasn’t a prime example of a Cavalier Coupe. The steering was decidedly suspect, for one thing, perhaps dating back to an altercation the nose had with a Jaguar some time ago. It will soon be pensioned off to make way for an automatic model to undergo similar engine modifications.
While this coupe certainly “whooshed” up the scale in top gear, it could hardly be described as turbine-like for, in spite of the balanced bottom end, it retained the typical harshness of a big four. In fact this “Opel” exhibited typical Vauxhall harshness and boom, though without the transmission snatch that so many have. This meant that 10 m.p.h. in third gear could be used in town without the engine exhibiting too much discomfort, remarkable flexibility.
There is one four-cylinder saloon or coupe which Blydenstein acknowledges to be superior to this Cavalier in terms of performance, particularly in top gear, and fuel consumption. That is the Blydenstein Vauxhall 2.3-litre Magnum/Firenza! I can vouch for that, too, for my test of his 2.3 Firenza Sport SL in the March, 1973 issue of Motor Sport shows it to be fractionally superior in standing-start figures in all except the 0-90 m.p.h. region. But whereas that Firenza pulled a 3.455 to 1 axle ratio, the Cavalier Coupe had a 3.670 to 1 final drive, which made itself obvious by the buzziness at speed. In retrospect I was a little more impressed with that Firenza in most things except style than I was with this latest offering. – C.R.