TUNING TOPICS

All-Round Improvement from a Blydenstein Viva 1600

VAUXHALL’S 1,600-c.c. s.o.h.c. engine, fitted to the Viva and Victor, seems unlikely to find a place of affection in the memories of British motorists. Both economy-minded and enthusiastic Viva drivers tend to be disappointed by heavy fuel consumption allied to average acceleration and a top speed of less than 90 m.p.h. Definitely not what one would expect from a modern overhead-camshaft 1.6-litre installed in a small and reasonably light car. In a-litre GT form the Viva weighs approximately 1 1/2 cwt. more than a Twin-Cam Escort.

However, from the conversion specialist’s viewpoint there are a number of points in the Vauxhall’s favour: in fact all the basics for a sprightly saloon are there, the all-round coil-spring suspension (a dead axle system of rods similar to an Alfa Romeo is used at the rear), disc/drum braking and accurate rack-and-pinion steering all being quite up to the addition of extra power in standard form. The 1600 version is especially attractive at £890 to an enthusiast who cannot wait for, or afford, the GT at £1,086 hut is prepared to spend some time working on the car to make it perform and handle rather better than the men of Luton had envisaged … this sort of activity could be construed as competitive, and we all know that word is worse than a four-letter Anglo-Saxon epithet to General Motors, Detroit.

In spite of the officially frosty attitude there are two firms in Britain who, with some help from well-hidden sympathisers inside Luton, actually compete and sell some of the results of their labours in the form of performance parts for road cars. The persistent Vauxhall competitors are Coburn-lson Ltd. and W. B. (“Bill”) Blydenstein. The latter concentrates on circuit racing with a Shaw & Kilburn Visa GT in Group 2 International saloon-car events for this year. while Chris Coburn participates in all sorts of loose surface events, also with a GT. Naturally this reflects in the equipment they sell, Coburn-Ison’s exclusive lines being equipment like sumpguards and reinforced suspensions, while Blydenstein looks after the speed side, both in straight line and cornering parts.

The Blydenstein car we tried was a 1966 SL which had covered over 60,000 miles acting as a test bed with both a 1,159-c.c. engine and the current 1,559-c.c. s.o.h.c. unit giving an extra 18-20 b.h.p. over the standard product. Although this improved the car immensely it was the £47-worth of suspension improvements which gave us the most pleasure, making the car almost foolproof in its behaviour even when driven in a plainly suicidal manner.

The engine work consisted of throwing out the standard Zenith carburetter and fitting a Weber twin-choke 28/36 DCD of the type fitted to the 1500 GT Cortina prior to the advent of crossflow models; it fits on the standard inlet via an alloy plate adaptor. A modified cylinder head with 9.5-to-1 c.r. is matched to both manifolds (£35). Prototype tubular steel exhaust manifolding was also used for our test in the pattern of four branches into two and then a single pipe underneath the passenger compartment; the production price for this revised plumbing seems immodest at £28. The Weber carburetter complete with all linkages and an effective air-cleaner costs £34 15s.

The suspension modifications were comprehensive with new Spax adjustable, by a screw, shock-absorbers redrilled Ventora top wishbone arms at £17 a pair to give negative camber angle of just over one degree at the front wheels, and a Viva GT anti-roll bar (£15), also fitted at the front. Wider, 5J Cosmic aluminium wheels were also supplied with Michelin XAS tyres; the wheels are £8 each, but Dunlop steel ones are available in the same rim width at nearly half the price of the attractive Cosmic design.

The only other extras fitted to the car were a comfortable bucket scat and an instrument binnacle containing an oil-pressure gauge, reading 75-80 lb. above 3,500 r.p.m. because an uprated Viva GT pump was installed, an ammeter and an 8,000-r.p.m. Smiths electronic tachometer.

Labour charges for installing all the equipment we have described at Blydenstein’s clinical Hertfordshire railway station premises would be £33.

It was fascinating to walk around this four-year-old Vauxhall and see that, in spite of obvious loving care (all the bodywork nooks and crannies had been cleaned), there were unsightly areas of rust appearing in its light blue paintwork. Driving away in the car we quickly found that this hadn’t affected the bodyshell unduly, for there was a remarkable absence of creaks and groans while driving along a bumpy country lane.

A movable red pointer on the tachometer was set for 6,600, but we were told to use 7,000 r.p.m. to get the best performance figures. In fact we tested the car with both a 4-to-1 final-drive ratio and a 3.9-10-1, after the latter differential seized during an acceleration run, breaking the propshaft close to the axle casing. So far as we know this is a freak failure, as the racing Visas with close to 200 b.h.p. have had only one similar breakage, using the same components.

More to the point in our case was that we conducted the entire public road testing and fuel consumption measurements on the 3.9-to-1. plus some acceleration figures before the propshaft broke and the 4-to-1 was substituted to record a new set of performance figures, which were in fact better in acceleration and top speed respects than the earlier times. Our fuel economy measurements were all taken using the 3.91 drive. The gear speeds in both cases were around 35 m.p.h. in 1st, 50 in 2nd and the lumbering legal limit in 3rd.

The engine needs the use of half choke, plus a couple a dabs at the throttle to start it on a COW morning; the choke can very quickly be dispensed with but the car always tended to run cold no matter how hard we “Viva’d”. Even in modified form the 1600 engine is not a unit to send the r.p.m. needle soaring round the dial. Normally one would expect the euphemism “. . . a lusty puller” applied, but since this nearly always means the writer considers the engine a rough old nail, we will refrain because the engine buzzes away giving plenty of torque from 2,000-5,000 r.p.m., getting progressively smoother between 6,000 and 7,000 r.p.m. Much more impressive is the way that the car will cruise on the Weber’s primary choke until an honest 85 m.p.h. is exceeded, or more with a favourable breeze. An honest 100 m.p.h. call be exceeded with a tailwind or downhill.

The engine is nothing like as rough as the BL Maxi unit when extended, but it does have that charming ability to cruise at 65-70 m.p.h. on a practically closed throttle, which is one reason for the Blydenstein-modified Viva managing an average 25.3 m.p.g. and a lowest of 24.2 compared to the ‘standard car’s 20-ish figure.

Standard brakes proved to be good enough for all but the hardest country lane driving, and even under these conditions it is the smell emanating from the overworked friction materials that deters the driver, not fade—though doubtless that characteristic would quickly set in if the warning was ignored.

We derived a great deal of pleasure from spirited cornering as the car has a much better contact with tarmac than even a Twin-Cam Escort. The rear wheel lifts slightly under hard acceleration from a hairpin, or on faster curves if the car is pushed to its limits—but this is probably a good thing because the consequent loss of power brings even the tightest situations back under some semblance of control!

On dry roads the rear is unlikely to swing out with the application of power and the appearance of greasy or wet roads doesn’t reduce the road-holding abilities as much as is the case with the Avenger and Escort family boxes. Anyone who has driven a Fiat 124 will find that the Vauxhall is very similar in respect of traction and handling characteristics; in Blydenstein form the car merely stays on the road for longer to exhibit less understeer than the production Fiats and Vauxhalls. Body lean is noticeable only by its absence, while the ride is quite suitable for family outings along Britain’s lesser lanes.

The noise level inside the car is not exhilarating or unduly tiring just gargling sounds from the large carburetter air filter and an occasionally pronounced hum from the camshaft drive belt.

I think it was D. S. J.’s wish that I should test “. . .something like a Viva with a noisy exhaust”, and except for the Blydenstein car being quieter than the standard 1600, which in my view ranks as one of Britain’s most insipid and greedy cars, I have now complied and can recommend the Blydenstein conversion as improving all aspects of performance, which is what all tuners should aim for with their milder road kits . . . fewer than 12 of them actually manage it! Worse still, is that there are two firms to my knowledge actually producing cars that are slower than standard on a regular basis. The trouble is how does one prove that every single car that firm has modified is no good ? And until we can prove that, MOTOR SPORT readers will have to go without sensational name disclosures!

Performance*

0-30 m.p.h. .. 3.7 sec.
0-40 m.p.h. .. 5.4 sec
0-50 m.p.h. .. 8.6 sec
0-60 m.p.h. .. 12.1 sec
0-70 m.p.h. .. 17.5 sec
0-80 m.p.h. .. 25.1 sec

Gear speeds :

1st. 35 m.p.h.
2nd 50 m.p.h.
3rd 68 m.p.h.
4th 99.3 m.p.h. (4-to-1 final drive)
4th 98.3 m.p.h. (3.9-to-1 final drive)
Overall m.p.g. : 25.3

Converters : W. B. Blydenstein, Station Works, Nr. Shepreth. Herts.

* Two runs in each direction using a fifth wheel.