Mr Clarke, 63 ''going on 20'', of Cranbourne Park in Victoria, has an unusual and volatile hobby: fixing jet engines to cars.

He is in town for the Summernats, and he has brought with him a 2000 Mazda RX-7 Series 3, complete with a jet engine formerly owned by the Royal Australian Air Force.

Mr Clarke matter-of-factly said the car could only do ''about 160 miles per hour'' almost 260km/h.

Only?

But Mr Clarke said the Mazda was limited to the quarter-mile sprint.

''It's a relatively new car, and because the engine is so large you don't want to overdo it,'' he said.

By his own admission, when things go wrong in jet cars ''85 per cent of the time there's a fatality''.

''I guess it's like going down a mountain slope on a skateboard with no brakes or steering ... you can't just stop and get out,'' he said.

He lost a friend in a jet car accident two years ago, and has been in a nasty scrape himself.

''It dumped 70 litres of fuel over me, and if there had been a spark it would have been absolute chaos,'' he said.

Would he ever consider a less lethal pastime?

''No. They're like a drug,'' he said.

''You get such a high out of them, you're running into the world of the unknown.

''It's just the best feeling when you've done it and nothing has gone wrong.''

His wife thinks that he is positively certifiable, and Summernats promoter Chic Henry partly agrees, but Mr Clarke says he knows what he's doing.

''We still treat the management of jet cars as we treat fireworks from a safety point of view,'' he said.

''You've got to try everything once to know if it's safe.''

It is by no means a cheap hobby; Mr Clarke's Mazda cost him 12 months of work and about $200,000.

''Because it's so expensive to get [the jets] from the private sector, they all come from ex-military,'' he said.

''I've even got some from the Singapore air force.''

At least three jet cars will be featured during the action at the EPIC arena tomorrow night.