The engine is slightly lighter than the M3 and it really pulls the weight – it’s a smooth as silk.
The BMW M3 is a classic. First released in 1987 as a race homologation special for the European Touring Car Championship, the 16-valve, 240bhp road-going race car was one of the most desirable and relatively affordable sports cars of its generation. It placed exceptional handling and power within the grasps of the not-so sublimely rich. It was, and remains a legendary performance car.
Which is why, as we hurtled along Bruntingthorpe’s two mile runway with the speedo needle off the scale and the outside world zapping by ever faster, I couldn’t shake one thought out of my head. Why the hell would you throw away the engine and replace it with a V8 from a Range Rover?
“It’s what I had available at the time,” explained owner Wayne Greatrix, over a quiet coffee. “I used to run a Range Rover on track days. I lowered it nine-and-a-half inches on Leda suspension and had the engine professionally modified – and had a lot of fun on it. The traction out of the corners was amazing.”
He brought the Range Rover in 1992 and in 1997 took the engine out and had it worked by Birmingham based tuner Anthony Murray. The standard cams were replaced with 324 profile cams and the cylinder and valve heads were worked to free up breathing and venting. The compression ratio was also raised to 10.5:1.
The crank was upgraded to a cross-drilled, stainless steel JE unit which was then lightened and balance – and forged pistons replaced the originals. Under the original electronic fuel injection, the V8 struggled to make 300bhp so Wayne scapped it and opted for 48mm Dellorto carbs and downdraft tubes to squeeze more juice and air in to the engine.
The work extracted 362bhp from the engine, with a massive 440lb, ft torque which Wayne used to devastating effect during track days. He ran the modified and lowered Range Rover for a couple of years before a friend spotted an early M3 at a local salvage yard. Mechanically sound, the car had extensive panel damage – lots of little dents everywhere which looked like someone had set to the car with a baseball bat.
“I’d always wanted an M3 but never really had the money. It’s a classic shape, classic car – and this one just came up at the right time for the right money. It was in a right state though.”
He took it to a friend who specialised in body repairs and had the exterior restored to its former glory. He also had the leather interior reupholstered.
“I used it for general driving for a couple of years and really enjoyed it. The handling was superb and the engine was great – but I never took it on the track. I didn’t know that history so didn’t really want to risk it.”
As the M3 clocked close to 110, 000 miles, Wayne felt it was time to either replace or rebuild the engine.
“The belts tend to go around that time and not knowing that history, I wanted to do something about it. But at around £1500 to replace them, I got to thinking that it would be better to just replace the engine with my V8.”
Wayne had tired of the Range Rover on the track: a high centre of gravity meant the body roll was horrendous, particularly at speed, but he didn’t want to sell the engine having spent so much money developing it.
“It’s a very strong engine. Very, very torquey. To get that same level of performance out of the M3 engine. I’d have had to spend a packet. It didn’t make sense.”
As it turned out, the match was relatively straight forward, though minor under bonnet modifications had to be made to mount the aluminium engine. The Rover V8 is lighter than the M3 engine it replaced – but it’s around the same length so it slipped nicely in to the bay. The gear lever even slotted through the same hole that original did.
The M3 engine was cradle mounted but this was removed so that the Rover could be chassis mounted – for rigidity. Sump and engine mounts had to be designed and fabricated by DJM Motorspot to make the work possible. The stainless steel tubular exhaust headers had to be modified to fit by Milton Keynes based company Exhaust by Design – but the toughest part of the engine conversion was positioning the left-hand drive steering column around the engine. A larger Rad-Tech radiator was also installed which meant the brake servos had to be relocated.
Mating the Rover transmission to the BMW prop-shaft was simple; Wayne used a knuckle to link the two to transmit drive to the rear diff, though a shorter prop-shaft was needed to accommodate the knuckle.
With so much power being transmitted through the engine and gearbox, a heavy duty clutch was needed. Wayne found the ideal component from AP which was designed for the Lamborghini Countach. It has helped cut down on the number of gearboxes he is wearing through, and at £680 a throw (he’s blown three over the last 1000miles) any saving there is a welcome relief.
The original discs and callipers were replaced with AP racing components. Bigger 360mm front disc are clamped by four pot AP callipers, while the rear disc were left alone.
“I’ve never had problems with them over heating; it’s the front ones which seem to get all the work, so the rears didn’t need upgrading at all aside from new pads.”
Ride height was lowered by 40mm front and rear but Wayne retained the factory spring and damper settings with new fixed rate Bilsteins. He also upgraded the track control arm and anti-roll bar bushes to Group A touring car spec ones.
Power is transferred to the ground through 17 inch BBS rims – 8inch wide at the front and nine at the back – which are clad in Falken JRB rubber.
“I’ve used Falken tyres for 10years and never had a problem.”
Wayne says the engine and suspension work has transformed the performance of the M3. Where he felt himself wanting for power out of the Range Rover, the lighter body of the M3 almost feels as though it’s picked up and hurled down the road.
“It pulls like a train in every gear, and the torque is amazing. You can start off in fourth gear – but you can also be reaching to change for fifth at 150mph. It’s really incredible,” he said.
“The engine is slightly lighter than the M3 and it really pulls the weight – it’s as smooth as silk.”
Power to weight ratios are where the improvements really begin to show. By transplanting the worked Rover V8, Wayne has dramatically increased that ratio because he’s effectively chopped the vehicle’s weight in half. Where the Range Rover gave him around 170bhp per tonne, the M3 now delivers around 285bhp per tonne – for a fraction of the cost of tuning the original engine.
It also means the engine acts much differently now. Where the weight of the Range Rover would bog the car down down, the M3 launches itself with a hefty shunt in the back and a rorty, rip-snorty roar from under the bonnet.
“The first time out a Castle Combe was brilliant. It’s so quick in the dry that people can’t believe it’s an M3. In the wet, it’s a different story. It’s so twitchy that I don’t bother. You really need to get out and give it a good go in the dry.”
With his foot firmly planted during a brief test session at Bruntinghorpe, Wayne displayed just how impressive that power is. He fired the M3 around the shortened top part of the test track while snapper Harmer panned and clicked. With more than 350bhp under the right foot and masses of torque, the Rover could be prompted to stick its tail out when needed. Careful right foot contemplation was needed to hold it there, and Wayne seemed a bit worried about holding his car in a controlled four-wheel drift. We didn’t have time to test drive the car ourselves – Wayne had to get back to Birmingham to collect his kids from school.
Outwardly, the car appears to sit nicely on the road though it tends to push on through corners if not driven hard. Right foot control is where the secret to driving this car quickly lies. Overstep the mark and it’ll let you know. Learn to tame it, and it’d make any track seem a lot shorter. But that’s how this engine responds. Just look at its derivatives; early TVRs, the TR8, Marcos, Morgans….they all need to be mastered.
Wayne says the car probably owes him £18,000 all up – £10,000 for the car, parts and labour and £8000 for the engine work. But he sees it as money well spent. That said, he’s already contemplating new projects and would like to sell his M3 to help fund them.
He’d like to drop a 440bhp 4.5 litre Cerbera engine in to a 206′ shell to drive the rear wheels. It’ll be a ground up build and it will be built specifically for track days – it won’t have a scrap of non-functional interior trimming. First off though, he needs to track down an outfit which prepares the shells for rear-drive running gear. He’s promised to keep us posted.
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February 2, 2009
2000 - 2008, Articles