Millyard's MONSTER V12 Z2300

He's made five cylinder two strokes and a V8 from two Z1000 Kawasakis. How could he top that? The idea came to him at the Mechanics show last year - a V12 built from two Z1300 engines. He promised us the first ride and Roland Brown leapt at the idea.

ALLEN Millyard's first attempted burn-out doesn't work. The motor's torque can't overcome the rear tyre's grip and the big Kawasaki is pushed slowly forwards with its front tyre squeaking in protest. But he's not going to be beaten, and tries again.
This time the rear Michelin breaks traction and suddenly Millyard is sitting with a big grin on his face, revving hell out of his latest creation, which makes a glorious growl through its open pipes while smoke pours from the spinning rear tyre.
The 41 year-old nuclear research engineer from Thatcham in Berkshire has a good reason to be pleased with his unique, hand-built machine. At a glance it looks almost like a standard version of the gigantic Kawasaki Z1300 that was the final chapter in the 1970s' rush towards ever larger and more powerful superbikes. But this Zed is considerably bigger again, because it has two complete cylinder blocks, grafted together to make a 2300cc, 70-degree V12.
There's almost a sense of inevitability about the V12's creation, given Millyard's history of building bikes, especially old-style Kawasakis, with more than the original number of cylinders. After starting by creating Honda V-twins using a pair of C90 and then SS50 cylinders, he produced a string of Kawasaki two strokes with four, five, and even six-pot powerplants, based on the old aircooled triples. Then he built an even more ambitious special, a 1600cc V8 compiled from two four-cylinder Z1000 engines.
It was while he was at the Mechanics show with the V8 that the plan was hatched to go a stage further with a Z1300-based V12.
Not that Allen originally had the idea. "I was just there looking after my V8 and Dave Marsden of Z-Power had a couple of Z1300 crankcases for sale nearby. Some guys saw the cases and said, 'I suppose you're going to make a V12 next, then?' I said no, I wasn't, and they replied that it would be impossible anyway.
Of course, as soon as they said that, I had to build one. I spent the next two days thinking about how I was going to do it and by the time the show ended I'd worked it out."
Designing and building the V12 required plenty of thought even for Millyard, because this project was far more ambitious than the V8. The creation of the engine was similar, in that he once again retained the original cylinders as the front bank and grafted on a second set at the rear, using a shared crankshaft.
"The original cylinders are only five degrees from vertical but I wanted to make this engine symmetrical so I set both banks at 35 degrees from vertical to give a 70-degree V12," Millyard says.

WHEN Mike recently turned up at my workshop with his Honda 400/4 engine he had a sorry tale to relate. Although a little rattly the bike had been running fine when, while giving it a wash and check over, he noticed one of the front engine bolts was loose.
No problem thought Mike, reaching for the spanners. A moment later there was a loud crack followed by lots of loud swearing from the garage before Mike emerged covered in engine oil, clutching a piece of broken crankcase.
Oh dear. It turned out a previous owner had replaced the engine bolt with one just a little bit longer, and when Mike had given it a tweak it had cracked off a large and important chunk of the crankcase supplying the main oil feed to the filter.
Being a pragmatic sort of chap, Mike decided this was fate's way of telling him it was time to rebuild the engine, provided the casing could be repaired.

1: The 400/4 engine looks in fairly good nick, though is showing signs of several years of road muck accumulated in the cylinder and head fins. Not surprisingly it also looks a little oily too.