That engine

Freshly cast and machined crankcases form the basis of this 1200cc V-twin. Pistons are 90mm on a standard stroke, held by Carillo rods. “You can stroke them,” says John, “but you just get an increase in torque”. The heads are gas-flowed with larger valves and are twin-spark. “It helps power with a cleaner burn, but also it does help if someone happens to flood it while starting.” The Maughans crank and flywheel are lightened and balanced for the larger pistons, the alternator is a French Alton unit, while the starter is another French item, from Francois Grosset.

The modern Dell’Orto carbs transform the bike into feeling like a modern bike. “They help starting as they have a better pilot system than the Amal, plus we spent days on the dyno to find just the right set-up,” John says, in a relieved manner. Ignition is by Pazon: “I love Pazon, I try to use it on all my bikes – it’s just so easy to work on and gives no problems.”

But it’s not just a bolt-together job. John has to check and measure every hole in the new crankcases: “The castings are good, but they are all individual, so everything has to be checked. And the gearboxes (you can have a four-speed or a five-speed ‘Surtees’ box) can cause massive problems. I now have a jig to build the gearboxes and measure backlash. And the cases sometimes need machining to clear the selector shafts – it’s tight in there. If it all goes well, I can have one together in an hour – but I’ve had one that took two days!”

The gearbox is the only real Achilles heel, though. The exhaust, beautifully made by Competition Fabrications, is sand-filled and bent to mimic the MV factory systems. “Everybody uses Gold Star silencers, I thought the Norvin deserved better – but the customer can have what they wish,” said John, smiling.

“The heights in the box where the selector shafts vary slightly, it takes time to measure all the backlash to get them just right. Sometimes it takes a day, but the one I had took two days!”

“A customer looks at our website and likes the idea of a Norvin build, but can specify what they want. The standard build is what we consider to be the right mix of parts for price, but they can ask for different brakes, suspension, wheels, tyres, engine tune, gearbox, paintwork and even exhaust. They can have what they want.

“The only thing we can’t change is the layout of the frame and engine, fuel tank and seat – it took me eight years to get everything to fit perfectly and I’ve got the bits on the shelf – the more changes you want the longer the build can take.”

How long does it cost to build one? And how much? In a perfect world, not long. But it’s like a jigsaw, it’s okay if you have all the pieces available, but many of the parts come from highend, bespoke low-volume suppliers, whose lead-times can be long.

There’s not a huge demand for magnesium drum brakes, Vincent barrels or Norvin oil tanks! So a build normally takes around a year from initial conversations.

They cost from £40,000, but most owners want their own touches, so it ends up being more…