The Quantel Cosworth

 

"For Paul Morgan who laterwent on to co-found the Ilmor raceing engine concern , it was no reward for all the work put in on test bed running and development. 
The raceing engine was finally refined to produce at least 110 bhp at 10.500 rpm .

And so , for several years the Norton / JA engine dissapeared into limbo.
Then in July 1984 , an ex - road racer , and newly appointed Cosworth Director Bob Graves ,
whose Quantel company had joined Cosworths controlling company , UEI , was shown round the Northampton factory by Kieth Duckworth .
Bob spied a few dusty engines on a shelf and asked what they were, and leaned the sorry saga from the Chairman , who ended up by saying 
" You're looking at the only engine we have ever built which has never won a race " .

Kieth was happy to get rid of a couple of engines , but wanted no more to do with this failed project. The story is that Graves then spent four years - and 100.000 pounds - to prove him wrong. In 1988 he made his point - not only did Roger Marshall win the Daytona ' Battle of the Twins ' on his Cosworth engined bike , The Cosworth - Norton engined bike , The Cosworth - Quantel , but the machine went on to win major events at Spa ( Belgium ) and Assen ( Holland ) later in the year . Then , as Kieth told me :

' After the Daytona win we had the chance of takeing more orders for this engine , but by that time Cosworth was far to big to be playing around with things like that ' .


Bob Graves, a director of Cosworth, found the engines when searching through a store room. He purchased what was left and sent it to his home in Surrey where he had a private workshop and a considerable collection of automobilia exotica.

Bob Graves engaged three people to work on the project, Guy Pearson, John Baldwin and Gary Flood. The former two were skilled fabricators of stainless sheet alloys and aluminium, while Gary was a would be MX rider cum road racer. Guy and John had at one time worked for Surtees F1, and all three had combined to produce the Exactweld 250 two stroke racer on which Gary Noel would eventually win the European Championship.
The following is what Gary Flood told me regarding the detail that went into making the Quantel Cosworth a top performer.

Guy and John devised a fabricated chassis that attached to the front and top of the engine, with a fabricated swing arm and a mono shock mounted above the engine.
The engine was re worked in considerable detail. Without detailing the work done in any sort of chronological order, the following were things that had to be addressed.

The gear on the end of the crankshaft would slip. Kieth Duckworth suggested chrome plating the inside of the gear to give a certain interference fit, and once this was done no more slipping occurred. There was also a problem with a quill shaft fracturing at certain low engine speeds. Duckworth again came up with a fix which involved a change in both material and shaft diameter. Flood eventually re balanced the engine to a different balance factor.

Initial attempts to run a fuel injection system were disastrous, best described by Gary Flood as impossible to map to be suitable for track use, and likened it to an on/off system - with no in between ! 
Amal 40mm Concentric Mk 2 carburettors were fitted to get some power output figures, and worked reasonably well, but the original design provided a poor down draft angle for the intake duct owing to the original requirement being that the engine should be also suitable for road useage.
The team modified the intake to create a greatly increased down draft, thus making fuel injection a necessity. Kieth Duckworth had a system built up by Cosworth technicians that proved to be totally satisfactory in terms of power delivery and throttle control.

Cam profiles were originally lifted straight from the Cosworth DVA engine, with valve lifts and durations being equal, exhaust and intake, and set at 102 degrees maximum lift both. Maximum valve lifts were 10.4 mm, and at 1mm lift, durations were 274 degrees. Later Gary Flood changed these settings to give intake full lift at 98 degrees ATDC, but despite this early opening, no problem was ever found with valve to piston clearance. Later the intake cam was changed to one developed by John Judd when working with the Williams F1 team, which gave 1.5mm more peak lift.

Squish was set cold to 0,024 thou. but was found to shrink dynamically to 0.006 thou.

Exhaust header pipes were in 18 swg, of 1 7/8 inch outside diameter running into a collector with a parallel outlet pipe.

Dyno testing was done on a Heenan and Froude water brake, and just over 120 bhp was measured at the gearbox output shaft.

Testing showed the gear spacings to be less than ideal, the original design was for a 20% drop between each gear. It was found that the gap between fourth and top was too great and so the gears were re designed to give a drop of 12% which eventually proved ideal.
The clutch was of the diaphragm spring type which Gary Flood described as 'borderline'.

The Quantel Cosworth was raced very sucessfully by both Roger Marshall and Paul Lewis.
Following a period in retirement it was eventually sold to a German collector."

Date de dernière mise à jour : 29/01/2019

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