A Class Act

David Piper’s new red 250LM Ferrari (chassis 8165 for the fanatics) came screaming up the hill through the drizzle, skittered round Paddock Bend, narrowly missing that very solid railway sleeper wall, and fish-tailed its way along a wet top straight past the pits, with a dark blue backmarker tucked up under his tail in the spray cloud. This is what we had come to see on 6th August 1966 at Crystal Palace, and we looked right to Paddock Bend waiting to see championship leader John Miles come into view in his potent Willment Elan. Wait a minute! This is the first lap — that couldn’t have been a backmarker! Close look next time around . . . there it is, still tucked under Piper’s tail. Looks like number 92 through the spray — programme says “Digby Martland & Chevron GT” — only a 1600cc Ford twin cam against the Ferrari’s 3300cc! Okay, so Crystal Palace is a tight little circuit, and it’s very wet, but Miles is miles behind! We had better take notice, and so it stayed for all ten laps, with Piper winning by just a few feet.

The Chevron had announced its presence at its home track Oulton Park just two weeks earlier, when Digby Martland had a runaway first time out victory and had smashed the lap record into the bargain. Two weeks after the Crystal Palace race, Digby was back at Oulton. Having missed practice, he had to start from the back of the grid. No chance, we thought; it is only a seven lap race and Charles Bridge is on pole in his lightweight E-type. But Digby went past Charles after four laps, finished ten seconds ahead and took nearly another second off the lap record he had set a month earlier.

As if this stunning arrival of a new car needed any reinforcement, designer and builder Derek Bennett took his 2-litre BMW engined version to the Oulton Park Gold Cup meeting and ran second to David Piper’s Ferrari until the engine decided to transfer all its water to the piston chambers, so Derek only finished fourth. The Chevron had arrived and Derek couldn’t make enough for 1967.

Derek Bennett ran a general motor repair business as well as building racing cars for himself and tuning engines for other racers. He started with a winning JAP-powered midget speedway racer on the Northern dirt track circuits. He then turned to road racing and constructed cars to the 750cc and 1172cc formulae. After four years with a successful Lotus Elite, a Formula Junior Gemini and an F3 Brabham, Bennett constructed the first Chevron, a two-seater clubman’s car with cycle wings, similar to the Lotus 7s, Mallocks and Terriers of the era. This Chevron B1 was a winner; it had an “unfair” advantage over all the other clubman cars and it had independent rear suspension. In 1966 several customer versions were built and designated type B2.

In July 1966, Digby Martland’s sensational GT, type B3, appeared, along with Bennett’s own BMW-powered version, designated B4. The new GT, like the clubman’s car, was based on a small gauge multi-tubular spaceframe, stiffened with pieces of steel plate welded to the sills, fore and aft bulkheads and a stressed duralumin undertray. The boxed-in sills led many to believe that the chassis was monocoque. The suspension was straight from the single-seater world. At the front was a pair of wide angled wishbones, with the anti-roll bar operating on the top wishbone and using modified Triumph uprights. The whole of the front suspension was rose-jointed and fully adjustable. The rear suspension had very wide based bottom wishbones, single top links and twin radius rods. The rear anti-roll bar operated on the bottom wishbone. The rear uprights were machined from magnesium castings and housed rear hubs of Bennett’s own design, using Hardy Spicer UJ’s and a sliding yoke, thus obviating the need for troublesome rubber doughnuts. Armstrong coil spring damper units were fitted front and rear. The magnesium wheels had 7 inch rims at the front and 9 inch rims at the rear. Girling disc brakes were fitted outboard on all four wheels. A Hewland ST five-speed gearbox was fitted, with the rear mounted engine canted over at 17 degrees.

The production cars of 1967 were designated B6, regardless of engine choice. Derek Bennett was now a racing car manufacturer and had moved out of Salford to an old cotton mill at Bolton. With so many orders, parts were put out to sub-contract, with chassis frames made by Arch Motors, the glassfibre bodywork by Specialised Mouldings, and specially tuned 180 bhp BMW engines supplied direct from Munich. At this stage there was no hope of producing 50 cars, so the B6 had to go into the Group 6 Sports Prototype category.

Type B5 was a one-off for David Bridges. It was fitted with a 1.9-litre BRM V8 engine with Lucas fuel injection, but still mated to the small Hewland HD fivespeed gearbox. It was entered for the BOAC 500 at Brands Hatch at the end of July with Brian Redman and Chris Williams driving. The car proved to be very fast and in Thursday’s practice was up amongst the Group 6 Porsche 910s, even beating Jo Siffert! They had persistent ignition trouble on Friday and so didn’t improve their position but nevertheless, they still remained ahead of every Group 4 car on the grid and that meant all the Porsche 906s and all the Ford GT40s. Sad to relate that the car stripped its differential after only half a lap, but Chevron honour was upheld with the Digby Martland/Brian Muir B6 corning home fifteenth, despite having no brakes.

The 1968 car was designated B8, yet so good was the original design that the modifications made were quite minor such as revised bodywork with wider wheel arches and a different nose intake for the larger radiators. The undertray was now bonded to the chassis frame and the front anti-roll bar was made adjustable. By the end of 1968, production of B6 and B8 cars totalled 68 and the car was homologated.

There was one more special based on the B8 chassis — the B12. John Woolfe ordered a car fitted with an ex-F1 Brabham Repco 3-litre V8. The engine bay was lengthened slightly to accommodate the engine, making the wheelbase 2 I/2 inches longer and big fat Brabham F1 15 inch wheels were fitted. The car performed well in all its British ten lap club races, and John Woolfe entered it for the 1968 Le Mans classic. Whilst good for short races, the engine suffered cylinder head gasket failure early on in the race, and the pretty blue and yellow car was forced to retire.

The Chevron B8s were doing very nicely on the club racing scene, but there was now some opposition from more than a few very talented driver designers, and other one-offs, such as Astra, Crossley, Daisy, Daren, Focus, Gropa, Jerboa, Martin, Nomad, Rawlson, Saturn, Spectre and Tadec. On the international scene, British drivers had taken the B8 abroad and found considerable success. But changes were imminent; the FIA was changing the rules for large sports cars and for 1970 was to institute a European two-litre sports car championship. Cosworth was developing the 1600 FVA up into the 1800 FVC, which should then have enough power to match the BMW, Porsche and Abarth engines. Lola were talking of developing a two-litre sports car based on the T120 hillclimb car. Derek Bennett now considered how he could improve the B8 to stay ahead of the opposition. The B8 would be categorised in the new Group 5, but its weight would still leave it behind the Abarth 2000S which had a very powerful engine, and anyway, Carlo Abarth was developing a new Group 6 car.

Derek shook down his new red B16 GT Coupe at Aintree in the last week of July 1969, and as was now traditional for Chevron, he lapped well under the outright circuit record. True to his principles, Bennett did not make change for change’s sake; “if it works, keep it” was his motto. The B16 copied the B8 in having a rigid centre section with bolt-on front and rear spaceframes to carry suspension and engine. Whereas people had thought that the B8 centre section was a monocoque (because Bennett riveted aluminium sheet over some areas of the spaceframe to give it rigidity) the B16 centre section was of monocoque style construction. It was made up simply and inexpensively from a number of separate aluminium box structures, joined together with aluminium plates. The suspension was from the B8, but the B16 was fitted with 13 inch wheels with 10 inch rims at the front and 14 inch rims at the rear. The planned engine was the new Cosworth FVC 4-cylinder 1790cc twin ohc engine which produced around 240 bhp at 9000 rpm. The engine would be mated to a Hewland FT200 gearbox and final drive. The body was by Specialised Mouldings. Those who said that the B16 body was inspired by the Ferrari P3 and P4 should look again at the bodywork created by New Zealander Jim Clark of Specialised Mouldings for the Lola T70 Mark 3B. The B16 was very sleek and surprisingly low, with the roofline at the same height as the rollover bar of the Chevron F3 car, but because of the full screen and roof, the B16 weighed in at over 600 kilograms.

Chevron were well ahead of the opposition in producing a car for 1970 in mid ’69, and intended racing the B16 throughout the remainder of the year to have a fully developed race-proven car ready for round one of the new 1970 championship. Chassis numbers one and two were entered for the Nürburgring 500 kms race on September 7th, with Brian Redman and Chevron director John Bridges as drivers. The FVC engine was not yet ready, and so Alan Smith-tuned 9 series FVAs giving only around 215 bhp had to be put into both entries. The B16 prototype was heavy, but Specialised Mouldings had produced new lightweight bodywork saving around 35 kgs, bringing the B16 down to about 570 kgs, but still very heavy in relation to the Abarth which was around 500 kgs.

The new lightweight bodywork proved to be a problem. The prototype had been set up with the earlier heavy bodywork, and now in practice at the Nürburgring the B16 was an absolute handful, wandering all over the road, making it impossible to point accurately at the corners.

For the rest of Friday practice, the car sprouted all kinds of nose and tail spoilers, plus softer suspension, but Redman was still seven seconds off the pace of the 2-litre Abarths. Reasonable perhaps with a 1600cc engine, and so thought Carlo Abarth, keeping his cars in the garage, but Redman and Bennett knew better. For Saturday practice, Bennett removed all the spoilers, kept the soft suspension, but changed the castor angles and fitted narrower tyres. Redman took 14 seconds off his Friday time, and put the B16 on pole position 6 1/2 seconds ahead of the fastest Abarth! Redman led the race from start to finish, taking fastest lap and the class record, crossing the line two minutes ahead of Toine Hezemans, three and a half minutes ahead of Gijs van Lennep and six minutes ahead of Johannes Ortner in their much more powerful Abarths. The gauntlet had been thrown down.

Two works cars, now fitted with FVC engines, went out to South Africa for further development, starting with the Kyalami 9 Hours race in November. They proved to be very fast, and one can only wonder whether this didn’t lead to complacency back in Bolton, for following his defeat at the ‘Ring, Carlo Abarth was spending the winter lightening his cars and grtting more horsepower from the engine. The all new monocoque Lola T210 meanwhile weighed in at only 470 kgs.

The first race of the new championship was on April 19th at Paul Ricard. Most of the British contingent had used the BOAC 1000 kms as a shakedown race, which had shown up some problems with the FVCs trying to run on water instead of petrol! Jo Bonnier arrived with the first of the Lola T210s painted in pale blue for its French owner. Chevron and Abarth would have been happy to have seen the car stay at the back of the grid, but Eric Broadley and Bonnier convinced the customer that if the Swedish ace was allowed to drive in this race, the car would then be perfectly set up for the rest of the season! Permission granted, Jo thereupon promptly put the car on pole, three seconds ahead of the new powerful lightweight Abarth 2000SP.

Hearts sank at Chevron. Even Brian Redman could not be expected to make up for 100 kgs against Jo Bonnier. The very long straight at Castellet helped, however, because having the same engine, the Chevron and Lola appeared equal on top speed, the extra weight of the Chevron merely holding it back on acceleration. With much opposite lock through all the twisty bits, Redman finished up only 0.3 seconds slower than Bonnier.

The Lola led for much of the race, but a misfire towards the end let Redman through to win for Chevron. Thus it remained for most of the year; the light Lola 1210 always faster than the pretty B16.

Bennett decided that the heavy windscreen and roof must go; Chevron must build a lightweight spyder. The B16 coupe would still be run, because with 25 cars built by August it was re-classified and homologated into Group 5 in which class it became the fastest car on the tracks and proceeded to clean up. The B16 spyder, still heavier than the Lola T210 at 500 kgs, was ready by the end of August 1970, and was entered for the Nürburgring 500 kms. Could Chevron do it again with a brand new car? Brian Redman said “yes”, and put the car on pole with a shattering time of 8m 12.5s, which would have put him next to Jim Clark on the front row of the 1967 GP grid! Arturo Merzario took second place on the grid in the Abarth 2000SP with 8m 23s, and Chris Craft in Alain de Cadenet’s Lola T210 was third with 8m 23.6s. Vic Elford in the works B16 coupé recorded 8m 39.6s. In the race, Redman set a new lap record of 8m 14.4s and with some two minutes in hand over the next car, caught fire when a fuel line shook loose. Craft was now leading, but his engine put a rod through the block and Elford in the Group 5 coupé squeezed past Merzario to score two in a row for the B16 at the ‘Ring.

The fastest B16 coupé on the circuits in 1970, was a white one driven by BMW development engineer Dieter Basche, who had fitted an F2 16-valve unit with a special crank to bring it up to 2 litres. The noisiest B16 was undoubtedly the yellow Belgian car of Julian Vernaeve and Yves Deprez who fitted a Mazda Wankel rotary engine. The Wankel-engined car ran in several of the 1000 kms and at Le Mans as well as the 2-litre championship, but had many mechanical problems.

Having failed to maintain their record of winning first time out, the Chevron B16 spyder made up for its failure at the Nürburgring with a spectacular finish to the 2-litre championship at Spa on September 20th. It was a cliffhanger all the way, with Redman in the B16 up against his fastest adversary, Jo Bonnier in the Lola T210. The two cars were never more than two seconds apart for the whole race, with the championship spoils ready to go to the race winner. Redman had pipped Bonnier to pole position with a lap of 3m 39.3s to Bonnier’s 3m 40.2s, and this five seconds ahead of the next car! On the last lap, the two cars were side by side, with Bonnier on the inside going into La Source. Lola had the corner, the race and the championship, but Bonnier locked up, went into the corner too fast, half spun and stalled. Redman nearly hit the Lola, but managed to scrabble around the yellow car to race down the hill to take the chequered flag and give Chevron the 1970 championship title. GJ