Eisenberg V8: 480bhp twin 'Busa-engined beast
Speed record breaking superstar and general madman Zef Eisenberg has taken all of his high-speed learnings and poured them into a limited run production bike – the Eisenberg V8.
Built from two Suzuki Hayabusa engines and housed in a custom steel trellis frame, the machine is unlike anything that’s come before. We met up with Zef recently and he gave us the inside line on the project.
"I can’t quite remember when but I had this idea once of having a V8 engine in a motorbike," says Zef. "We know it’s not the first one done but I like things that look correct – that look like a motorcycle should. I also wanted it to be quite light, so I ended up working with RPE engines.
"They’d already done work with mating two Hayabusa heads to a sandcast bottom end but I wanted something more compact. We ended up creating this naturally aspirated V8, which produces 480hp at 10,500 rpm. Running a flat plane crank, the same configuration that Ferarri use, because we wanted it to sing and howl just like an F1 car."
Unlike most of the other companies that produce bikes like this, Zef’s main concern was that it looks and handles just like a regular motorcycle. Key to this was keeping the weight down, so they worked hard on producing an engine that doesn’t require a balance shaft, which means the whole engine, in ready to run trim, weighs just 80kg.
Bolted to the back of it is a Quaife gearbox, that operates just like a regular bike. Such a big engine has other clear issues.
"We wanted the engine inline but we had obviously concerns about torque reaction," adds Zef. "To combat that the gearbox has been created with a counter-rotating centrifugal clutch. The result is that the clutch rotating in the opposite direction to the crank reduces torque steer to nil. There’s virtually no vibration – you could put a coin on the block and it wouldn’t fall off.
"The real work and challenge, from when we started this project four years ago, was that we didn’t realise the amount of work required for heat reduction. It’s a major problem. So to sort it, we put a radiator underneath, which is designed for low speed riding, as well as one on the front for high-speed riding.
"The radiator has almost no effect on aerodynamics at all – most of it bypasses the frontal area off the mudguard - it’s only the air in the deadzone that goes in the radiator. We’ve teamed up with ProDrive to do full Computational Fluid Dynamics (CFD) and flow analysis of water and air flow around the engine."
The team’s work hasn’t just been mechanical – they’ve been doing a lot of work on the electronics too, including Pulse Width Modulation (PWM) controlled fans that slowly ramp up their speed as the temperature increases, so it doesn’t just sound like a hoover as soon as it gets hot.
They’ve also wound their own alternator to supply all the electricity it needs to run, while the really fun stuff is run through a Motec ECU, with a ride by wire Jenvey fuel injection system that operates eight independent throttle bodies.
This allows them to create an electronic safety net that can shut down cylinders to calm the throttle response down – rain mode chops it to 240bhp for instance. Even the small stuff has had real attention.
"For this sort of power you should really use a 630 chain but 630 chains are heavy, suck more power and are generally more cumbersome," says Zef. "I wanted to use a 530 chain but the problem with a bike such as this would be the stresses on the chain as the tension changes through the suspension movement.
"To prevent this we’ve used a concentric swingarm, which pivots on the sprocket, but we’ve done a lot of work to prevent the chain pull affecting the suspension movement."
As you’d imagine with a bike like this the spec-sheet is dripping with top spec parts including BST carbon wheels, custom Nitron shock, ISR brakes and a bespoke ceramic coated exhaust by Akrapovic.
Nothing like this comes cheap however, and while the price hasn’t been set just yet, when it goes on sale earlier next year it’s expected to sell for £150,000.