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One for the record books


IN UTAH JCB's Dieselmax vehicle, powered by 750 hp versions of its 444 engines, recorded an average speed of 350.09 mph at Bonneville Salt Flats in Utah last Wednesday, topping its own speed record for dieselpowered vehicles set the day before.

JCB believes its recordbreaking project will repay its multi-million investment by giving it a lead over rivals in the development of more powerful, cleaner-burning construction equipment engines.

The firm is now confident the work it has done on combustion, cooling and fuel injection will enable it to make four-cylinder engines that do the same job as a bigger six-cylinder.

Chairman Sir Anthony Bamford said the 20-month project to create the world's fastest diesel vehicle had given the firm invaluable 'fast track' research into the engine and fuel systems.

He said: 'Only I know how much it cost but I can tell you that it has been fantastic value for money. We have been able to prove that we have a whole range of engines with the 444 design.

'This shows the benefit of starting with a clean sheet of paper. We are not redesigning end-of-life engines, like our competitors.'

He added: 'This shows the capability of our engines and it shows that British engineers are fantastic. In Britain we don't laud our engineers enough, but this has been achieved with an all-British team.'

The work required to create such a fast vehicle as the Dieselmax has given valuable insight into the power systems, according to those involved in the project.

The key benefit has been the ability to increase the engine's power density, which will enable it to produce physically smaller engines, and to widen the range of equipment JCB can put its own engines into.

One senior source said: 'This work will blur the distinction between four-cylinder and six-cylinder machines.'

According to project director Dr Tim Leverton, the man steering the Dieselmax development, the benefits for plant will extend to both power and emissions.

He said: 'People will ask: 'What has this got to do with construction equipment?'

But we have learned a lot. We have pushed the performance very hard with the Dieselmax, but it should result in a more compact unit for 150 hp to 200 hp applications, which will be crucial, given all the additional kit required to meet emissions requirements. And there will be an advantage in the marketplace for those who can substitute six cylinders for four.'

More powerful engines will enable JCB to put the 444 range into more of its equipment, as well as allowing it to build marine engines for the first time.

Ian Penny, director of diesel engines for JCB's engine partner Ricardo, said that the 'cool combustion technology', using cooling systems together with a low compression ratio, would help cut emissions.

He said: 'The benefit is that if you can get the combustion temperature low enough, you don't have the Nox emissions or soot. It is already in passenger cars, but the challenge is bringing down the temperature of construction equipment engines, which traditionally burn quite hot. It works well at a high load but you need to do the same for a machine at idling speeds as well.'

Other Dieselmax elements that could be applied to plant included use of two-stage turbocharging, common rail fuel injection and filters.

'That the car has gone so fast without smoke shows what can be done. In 10 years, a lot of engines will look like this, ' said Mr Pennny.

To achieve its 350 mph pace, the Dieselmax has to have its twin engines running at a hot enough temperature to bring in the turbochargers. To bring the engines swiftly up to the correct heat driver Wing Commander Andy Green runs the Dieselmax against the brake.

It is only when both front and rear turbochargers kick in that the vehicle is able to reach its top speeds, accelerating from 150 mph to over 300 mph in seconds. After hitting top speed half-way through the nine-mile run, the vehicle is brought gradually to a stop using a combination of exhaust brake and two parachutes.

On the Dieselmax's fastest run last Wednesday, Andy Green actually reached 365.779 mph across a measured mile. But under International Automobile Federation rules, the official speed is taken from the average of two runs in opposite direct ions within an hou r. On the retu rn run, the engines took longer to br ing up to tu rbocharge speed, so Mr Green was only able to achieve 335.695 mph, for an official average speed of 350.092 mph.