With its twin-supercharged 27-litre V12 Rolls Royce Merlin certified at 3000hp, Rod Hadfield's Final Objective is the world's most powerful registered, street-driven car. Even Guinness World Records has recognised Rod's effort.

This article on Rod's Chev was originally published in the April 2003 issue of Street Machine

Disregarding the car's world-record status, the '55 is without doubt the most awesome car I've ever seen. I'm not making that statement lightly. My lifelong passion for all things automotive has taken me to some of the biggest shows in America and Japan not to mention filling my wardrobe to bursting point with hundreds of magazines covering the modified car scene from all over the planet. Final Objective eclipses all before it.

Essentially the car is a 1955 Chevrolet Sports Coupe that's underpinned by a fully fabricated box-section chassis, powered by a V12 Rolls-Royce Merlin – this one from a P51 Mustang. The huge engine feeds a two-speed Lenco and Chev C30 truck diff, which drives a pair of meaty Hoosier competition tyres mounted on massive 18-inch wide American Racing wheels. As staggering as these specs are, Final Objective is one of those cars that's more than the sum of its parts. It's also the end of a 15-year journey that has been Rod's life-long obsession.

From the moment Rod took possession of the '55 in 1986, he had the intention of stuffing it with the biggest, baddest, nastiest engine ever seen in a road-going car. He found a Centurion Tank V12 Meteor engine and it wasn't long before he was hacking out the '55's firewall to make way for his massive new acquisition. However, later in the project an even more desirable powerplant presented itself – the supercharged, Rolls-Royce V12 Merlin that now resides in Final Objective's incredible engine bay.

'Colonel' Hadfield has shot down 11 enemy planes and been on nine bombing missions. He gets around...

The DOHC, all-aluminium Merlin is one of the most famous aircraft engines, winning renown in the Spitfire and Hurricane, the Lancaster bomber and P51D Mustang. An engine of this heritage tied in well with Rod's interest in all things military and goes a long way to explaining the Col. R. Hadfield stamp on the door.

Before starting the project in earnest, Rod and Castlemaine Rod Shop's (CRS) Bill Mussett, who did much of the work, researched and studied a number of other V12-powered vehicles, including famous talk-show host Jay Leno's V12-powered roadster in the US. They discovered that crankshaft speed and rotational direction were the first obstacles. Due to the supercharger set-up, the V12 is actually mounted in the '55 back-to-front, so it rotates the wrong way. Secondly, the V12 was designed to drive a propeller at around 1800rpm and peaking at around 2600rpm, which is not much chop for street duties.

Solving both of these problems is a CRS-built transfer/step-up box that not only doubles the input speed to the two-speed Lenco gearbox but also reverses rotation. It's an incredible piece of workmanship and engineering.

The carburettors were yet another headache. They originally pointed towards the ground and had to be modified by Superior Aviation to function in a conventional orientation and run happily on pump unleaded. Then, because the massive supercharger got in the way of a regular belt-drive arrangement, an accessory drive system had to be manufactured to run off the engine's various external gear drives. To make things even more complicated CRS had to incorporate a special gearbox arrangement so the various accessories (power steering, fuel pump, alternators, and water pump) could be driven at different speeds.

Massive Attack is decked out to look like an aircraft from 352nd Fighter Wing, a unit based in the UK, equipped first with P47 Thunderbolts, then P51s

Even though the engine is all aluminium, its sheer physical size made it obvious the completed '55 was going to be pretty damned heavy – and the final figure is around 3500kg. To cope, two runs of 4x2-inch box-section steel were used to lay the foundations of the extensive chassis. The box section was internally galvanised to carry engine coolant between the four massive Aussie Desert Cooler radiators – two mounted in the boot and two up front. A grille at the base of the rear windscreen directs airflow to the double boot-mounted coolant radiators, along with the dual engine-oil coolers and the oil cooler for the Lenco transmission, which is likewise mounted in the boot.

Holding up the rear is a Geelong Differentials-