The cars : Blydenstein Vauxhall Chevette 1500

The Blydenstein Vauxhall Chevette 1500 proved that, with a few carefully-chosen upgrades, huge improvements can be made to the humblest of family cars.

Keith Adams recalls the work of one of the most highly-rated tuners in the business during the 1970s – and laments the unfulfilled potential of the GM T-Car.


Making the most of the Vauxhall Chevette

Blydenstein Vauxhall Chevette

Bill Blydenstein was a brilliant tuner. The Dutch-born Aeronautical Engineer started his racing career in 1958, and was good enough to bag a works Mini drive in 1962. But he was most famous for his relationship with Vauxhall, which he began in 1963 when he started racing Victor VX4/90s (FB) with Chris Lawrence.

By 1968, he’d moved into prepping cars, and brought Gerry Marshall in to drive. From there, a succession of victories followed leading to the formation of Dealer Team Vauxhall (DTV) in 1971. A string of victories followed in legendary cars such as the ‘Old Nail’, ‘Big Bertha’, ‘Baby Bertha’ and the rallying Vauxhall Chevette HSR.

When he wasn’t working in motor sport, Bill was upgrading Vauxhall’s excellent road car range. His passion was cylinder head gas flowing, and it was here – along with modest capacity increases – that brought genuine gains to whatever cars he converted. So, when DTV closed in 1979, Blydenstein continued developing tuned Vauxhalls for discerning customers.

The Blydenstein Chevette 1500 formula

Increasing capacity is a good starting point, though. The process enables an engine to work best at its most efficient speed. In the case of Bill Blydenstein’s Chevette, many of the gains made could be traced back to the longer-stroke crankshaft fitted to the car.

In the Chevette 1500, the bore and the stroke were increased. The increase in stroke from 61 to 72mm was accomplished using a steel crankshaft built up by Gordon Allen who also produced the very short connecting rods. Uprated Hepworth Powermax pistons required the bore to be increased to 81.75mm for an engine capacity of 1511cc.

To this bottom end was attached a DTV Stage 2 cylinder head and Lumenition electronic ignition. This resulted in an 18-20bhp rise in the power (at the wheels). Maximum power was developed at 5000rpm compared with 5600rpm.

Blydenstein Vauxhall Chevette

How did it go?

Blydenstein Chevette’s maximum speed was 98mph compared with 90mph for the standard model. It would have probably been quicker had it not been seriously undergeared, pulling 6160rpm in fourth at that speed. With a higher rear axle ratio, or an overdrive, it would easily have gone on to 105mph – impressive for the time.

Being a Blydenstein-tuned car, the fuel consumption gains were just as important as the improved performance and driveability. When Autocar tested the Blydenstein Vauxhall Chevette 1500, it reported: ‘Always observing speed limits on a cross- country journey gave a figure of 36.7mpg, while using the full performance potential could drop consumption to the worst figure recorded: 24mpg. The overall consumption during the test period was 31.2mpg and the range that the average driver may expect can be realistically set at between 30-35mpg.’

In acceleration tests, Autocar managed 11.4 seconds for the 0-60mph sprint and 22.7 seconds for 0-80. However, it was the in-gear acceleration that really impressed. The magazine reported: ‘The Chevette’s ability to accelerate from 50-70mph in top gear in just 9.5 seconds leaves such notable performance cars as the BMW 320i behind.’

Conclusion

Though carried out essentially as an engineering exercise, the fitting of a larger engine to the Chevette caused plenty of interest from potential customers. Along with this upgrade, a 2.4-litre upgrade for the Cavalier was also offered.

At the time of its test in 1976, Autocar concluded: ‘As the basis for a very interesting Group 5 rally car, the 1500 engine when combined with the low weight and good handling of the Chevette could be competitive, and we await with interest the stir that is sure to be made by this very astute piece of engineering.’

Interesting, that – in reality, Vauxhall and Blydenstein had something even more interesting up their sleeves.

But more than this, the Blydenstein Chevette proved the inherent potential of the basic car. Imagine if Vauxhall had installed the Cavalier’s 1600cc cam-in-head unit into the Chevette’s spacious engine bay. What a lovely thing that would have been…

Blydenstein Vauxhall Chevette

Keith Adams

31 Comments

  1. I always felt that the Chevette could handle a bigger engine. The Magnum version of the Viva did just that and a bigger engine would have opened up a much larger market.
    Missed opportunity indeed

    • Bigger engines were added to T cars in different regions of the world. In Argentina, they fitted a 1.7L Argentinian designed version of the GM Chevrolet 110 engine, but closer to home Opel did fit the 2.0 20E/EH CIH. I think the fuel crisis’ of the 70s probably saw Vauxhall not going down this route. Shame as we know that the HS proved that it could handle the power and was a good drivers car.

      • The Opel and Vauxhall OHV was said to have essentially been a downscaled version of the Chevrolet 153 engine, which includes the 110 and is part of the Turbo-Thrift Six family that shared bore spacing with the Chevrolet Small Block V8 and other elements from other GM engines (the Pontiac OHC 6 shared the Turbo-Thrift’s internal dimensions).

        Really the small block OHV deserved to be developed much further then was the case via a 5-bearing crankshaft and larger displacement just below the big black Chevrolet 110, if only to make the Blydenstein developed 1500 a production viable proposition.

        Vauxhall could have benefited from a larger displacement version of the OHV in place of the underwhelming 1.6 Slant-Four or Cam-in-Head, since the 1256 was apparently capable of being tuned to 80 hp.

        https://web.archive.org/web/20210824062544/https://www.chevettes.com/info-tuning

      • V6? Probably OK in the US as they don’t have many bends in the roads, but I think it would have been nose heavy here in Europe

        • Seconded on the V6 in the Chevette, at the same time Vauxhall would have certainly benefited from using such a V6 (albeit non-emissions strangled) in its other cars more than a decade earlier as an answer to the Essex/Cologne V6. Especially one capable of being mounted in FWD cars unlike the CiH Six.

          Together with an Opel/Vauxhall OHV developed along the same lines as Ford’s small block 4-cylinder engine and Vauxhall would have had more in its arsenal to take on Ford UK.

          Could see the South Africans fitting the V6 into the Firenza, like they did with fitting a V8 to create the limited run Chevrolet Firenza Can Am.

  2. The Opel Kadett versions of the T-car were interesting. There was a 1.6 with that Cavalier engine, a 1.9 and eventually 2-litre. There was also the semi-convertible Opel Kadett Aero, which looked great and provided open-top experience in a T-car

  3. This is very interesting. I was a keen reader of the motoring press back then, but I can’t recall this car. I do remember CAR magazine running a front page story on a Chevette powered by a turbocharged single-cam 2.3 slant four. It’s also interesting to recall that just a few years later GM would release the fwd Astra powered by a 75 bhp 1.3 “family 1” engine with performance that at least equalled that breathed-on Chevette.

  4. Surely, also Vauxhall could have fitted the 1800 engine in the Chevette, as they did with Viva & Magnum? Perhaps that would have taken some sales away from the Magnum’s core customer base though.

    I never heard of a 2.4 litre offering on the MK1 Cavalier – that does sound appealing!

  5. Surely, also Vauxhall could have fitted the 1800 engine in the Chevette, as they did with Viva & Magnum? Perhaps that would have taken some sales away from the Magnum’s core customer base though.

    I never heard of a 2.4 litre offering on the MK1 Cavalier – that does sound appealing!

  6. As a confirmed Vauxhall enthusiast I was seriously thinking about building myself a high performance Chevette road car using the 2.3 litre single cam engine as used in the Magnum (I couldn’t afford an HS). I even started to accumulate some of the parts I’d need for the project, but just never found the time. As others have already said, the Opel Kadette was available with a number of larger engines, so larger brakes & stronger axles were available. It’s just a shame that in the UK we only had the 1256cc engined Chevette.

  7. Advances in run-of-the -mill engines were about to take off around that time, weren’t they? Sobering to recall that the 1.8 slant four was barely more powerful than the 1.3 family one, and that the 1.6 outgunned it.

  8. The 2-litre 110bhp Kadett GTE was quite a useful tool, but my favourite Tcar engine was the 1.8-litre 16-valve Isuzu engine – only available in a saloon, but crucially made in RHD form for the Ozzy market. The easiest way to make a 1256 go faster was to fit a 28/36 Weber carburettor – this gave about 70bhp – power when you want it, economy when you don’t.

  9. I had a 1256cc Viva, if only I had known about the Weber option then, however most of my spare money was spent on cosmetic improvements (and fighting tin worm).

  10. You do wonder why Vauxhall themselves didnt capitalise on the OHV’s ability to stretch to 1500. Prior to the Chevette the HC Viva would have really benefitted. It would have made a far more useful and cost effective alternative to shoehorning in the heavy, rough and unreliable slant 4.

    • Fwiw Blydenstein was interested in further developing the OHV, however with Vauxhall’s focus on the Slant-Four and Opel’s on the CIH, together with GM being officially anti-racing meant there was unfortunately little opportunity to give it the attention both BMC and Ford gave to the A-series and Kent respectively.

      Now there are people out there demonstrating how the OHV could have been tuned and been reached its potential, although from the link to the following articles below it seems the Opel Kadett version of the OHV is deemed better than the Vauxhall Viva version.

      https://pdmclark.co.za/tag/gm-little-block/

  11. The simple answer, when the Magnum was axed, would be to introduce a Chevette using the 1.6 engine from the Cavalier. This would have made the Chevette into an excellent car, particular the hatchback, which would have become the sporty coupe the early adverts promised. I could imagine the 1.6 would have endowed the lightweight Chevette with 100 mph performance for little loss in economy over the 1.3, and improved sales as the Opel cam in head was a more refined unit than the 1256 Vauxhall engine.

    • I agree fitting the Cavalier 1.6 75bhp engine in the Chevette would have attracted sales, with its better performance in the smaller lighter body (provided the other spec and interior trim were improved as well.) A pity Vauxhall didn’t themselves raise the power from 58 to circa 70 bhp as per the Weber option.

  12. I did wonder why Vauxhall didn’t fit any larger engines in the Chevette, I presumed they were worried about losing sales from the Viva, Cavalier & Astra when it arrived.

  13. A 1.6 litre Chevette would have made sense when the Magnum was cancelled and could have stayed in production until the 1.6 Astra was launched. Vauxhall could argue that there was the Chevette 2300 HS for people wanting a performance Chevette, but this was a bit wild for regular drivers and considerably more expensive than the a standard Chevette.

  14. The first 1.3 S Astra MK1 was more powerful than the Chevette too (75bhp versus 58bhp) so it was inevitable the Astra would oust it. I never drove a Chevette but did drive a works Chevanne once or twice. It did the job it was used for adequately

  15. How many owners opted for the conversion? Many? Any? The price increase over the standard car was basically 40%!

    The power increase was about 40% over standard also, but the brakes and suspension was left untouched!

    Still, at least the spoilers made it “look less like a woman’s shopping car”. You have to love 1970s motoring journalists!

  16. Bill Blydenstein certainly knew his stuff – he was to tuning European GM engines what David Vizard, Daniel & Bunty at Downton were to ‘sixties BMC, or Kas Kastner in the ‘states was to Triumph engines.

    I always viewed the generic Chevette as a nasty low-budget thing, the sort of vehicle – in Estate, or even-worse the ‘Chevanne’ – was used in their thousands by the likes of the Gas Board, or the guy from Granada/Radio-Rentals who came to take away your failed colour-telly/video recorder and replace it with a new one.

    The UK MoD had a bunch of Chevette Estates as “Not-to-be-used-for-Officer-transport” vehicles in the same timespan.

    But I liked the litle GM 4-pot engine… part of me thinks that it should have been developed into a six-pot, going up to 2-Litre for sporting applications in the same sense as the inline-six used in the Triumph GT6. The ‘downdraught’ intake-ports-on-top-of-the-head-face is a bit reminiscent of the 1950s Bristol-BMW Six…

    As a sidenote, after the IRA blew off his left leg, a friend drove a Chevette retro-fitted with a Ford Essex-type 2-litre V4 [ugh] and autobox from a crashed first-generation Granada. Somehow he managed to get it listed as his ‘disabled mobility-car’ and on this basis dodged numerous speeding-tickets !

  17. @ Mowog, the Chevette was certainly misery motoring if you opted for the base E or ES model, so meanly equipped it lacked a rear demister as late as 1981. Yet this was only bought by people desperate to have a new car that could seat a family of four, and most buyers opted for the L or GL. In its late seventies heyday, the Chevette developed a reputation for being an easy car to own, cheap to maintain and being slightly stylish as a three door hatchback. Police forces, the MOD and Radio Rentals were all repeat customers, which suggested the Chevette was doing something right.
    Regarding officer transport, the army seemed to favour the Mark 2 Cavalier, as I can recall being stuck behind two containing army officers and their wives. Prior to that, the RAF used the Chrysler Hunter, probably as it was cheap more than anything else.

  18. But even the most basic Chevettes were still great fun to drive. Not powerful, but they had a well tied down axle at the back and great handling. Not hard to see that they could be even more entertaining with some extra power.

  19. There was a top trim Chevette GLS in hatchback & saloon form too. Had sportier wheels. Not many of those about though.

  20. The theoretically most cost effetive way to get more power for the Chevette would have been to use the Opel 1.6S CIH engine with 74 hp which was added for the Kadett C range by May 1977 for all body types (including the City-Hatchback) at least for Germany and Switzerland. There was even the option of an automatic transmission. The cars had a top speed od 98 mph and accelerated from 0-60 mph in about 12.4 s. I think that this could have made sense for the Chevette Hatchback – for the other body styles I’m less sure as the Viva/Magnum HC with the 1.8 l slant four would have been very close in size (and price) to a Chevette 1.6S. Speaking about Bill Blydenstein, I was always astonished by the results of his tuned 2.3 litre engines. I just had a look at David’s excellent website Vauxpedia (chapter Viva/Magnum HC road tests) to find some road tests concerning Blydenstein powered Firenzas. The results were really surprising; 0 to 60 mph times slashed by nearly 3 s and fuel consumptions which were even better than the standard engine. I knew the slant four quite well (FD VX 4/90 with o/d and FE VX 4/90 automatic) with its strangled feeling at higher revs. I never understood that Vauxhall couldn’t learn from Blydenstein’s work to rise the slant four to an much higher level…well they did it for the Firenza Droop Snoot but this one wasn’t really a “volume” car.

  21. @ Ruscho, the Magnum had gone by the end of 1977 and a 1.6 Chevette would have been a logical replacement as it would have offered similar performance to a 1.8 Magnum, but with better economy. A warm hatch 1.6 S could have been quite popular as it was more contemporary looking than the Magnum and the lighter body could have made driving fun.
    The slant fours were quite good engines, but Vauxhall never exploited theirt true potential, except with the Chevette 2300 HS and 1977 VX 490, which sold in very small numbers and weren’t considered mainstream. I suppose the move to using Opel drivetrains in the late seventies would have made any improvements to the slant fours a waste of money.

  22. As the Magnum’s were discontinued at end of 1977, the run out Viva GLS was probably the last hurrah for the HC range (same look & features as the Magnum but with the 1256 engine).

    The Magnum 1800 was an aspirational car for me in 1977 – never achieved though.

  23. From all the comments here, it seems a 1.6 litre Chevette using the Opel (Cavalier) 75bhp engine would have fitted the bill. A useful 17 bhp above the 1256cc. Perhaps the Magnum 1800 could have been deleted in favour of the 2300 /108 bhp

    • @ Hilton D, the Magnum 2300, a real Q car that could take on 2 litre Capris and win easily. However, the car used the slant four that would be deleted with the end of the VX in 1978, so the Magnum sadly had no future. Also Vauxhall were keen to push the Belgian built Sportshatch as a family sized sporting Vauxhall, and the 2000 was a fine car, 110 mph from a sweet and refined Opel CIH engin.

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