The Irving-Vincent - Anachronistic Trackday Missile

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The Irving-Vincent

Let’s say you are the head of a successful engineering firm in Australia. You have a full compliment of advanced casting, prototyping and milling machinery at your disposal and years of R&D experience in various avenues. And you happen to be passionate about motorcycles.

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If you were like most people, you’d probably use the facilities at your disposal to build some trick bits, maybe even build a complete bike.

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If you were Ken Horner, you’d resurrect The Vincent and turn it into a category-smashing racing historic superbike that can, and does, blow the fairings off all comers.

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That’s the story of the Irving-Vincent in a nutshell. Ken and his brother Barry of KH Equipment began the Irving-Vincent as an after-hours exercise to demonstrate their engineering talents in a high profile, spectacular fashion. Few would have believed back in 1999 that Ken and his crew would bring back Vincent in a way that would stun everyone in the motorcycle racing scene who was unfortunate enough to get blown away by one of Ken’s creations. Here was a true-to-the-original recreation of one of the single most legendary motorcycles of the 20^th century – updated with enough tech to make it staggering powerful and ridiculously quick round a track, to the point of competing against modern machinery. Despite using engine and frame architecture that dated back the 1930s.

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The Irving-Vincent story begins, naturally, with the original HRD Vincent Rapide and Black Shadow. The Vincent story is well documented, and I won’t repeat it here, but to summarize Phil Vincent bought the rights and tooling to defunct Howard Raymond Davies Motors in 1928 and set about developing his own brand of motorcycle. He hired Australian engineer Phil Irving to help develop an in-house engine design; originally an air-cooled 500cc canted-forward single (housed in models dubbed the Meteor and Comet), it was later developed into a 998cc V-twin that was released in 1936 as the Rapide, which would prove to be one of the most powerful motorcycles of the era. After the Second World War interrupted production, the Rapide was refined and developed and a new sportier variant introduced – the legendary Black Shadow. Production would cease in 1955 but the legend of the menacing, powerful, fast, and sure-footed Vincents terrorizing unsuspecting riders on backroads would only grow as the decades passed.

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Ken Horner was familiar with Vincents, having raced a sidecar outfit powered by a Vincent V-twin in the 1970s. He was also a fan of Phil Irving, and had the opportunity to chat with Irving about his V-twin design and its capacity for further development. Ken claims that the Irving-Vincent project began as a high-profile engineering exercise that would demonstrate the capabilities of his firm, as well as continue the ideas proposed by Irving. At the time he was producing air starters sold under the Austart name – functional and necessary, but hardly sexy and far from glamorous. So he set about developing a racing motorcycle that would showcase his talents and promote his company. Despite all its potential shortcomings (or maybe because of them?) he would use the antiquated Vincent V-twin as a basis for development. As the name “Vincent” was already trademarked, he called his bike the Irving-Vincent in Phil’s honour.

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A painting by Harry Whitver of the legendary Phil Irving.

The project began in 1999, when Ken began searching for suppliers of remanufactured Vincent engine components. Finding that parts were exorbitantly prices and insufficient for the goals he had in mind, he decided to build the engine from scratch with some help via Terry Prince Vincent in New South Wales. Ken designed and manufactured the bottom end components and crankcases at KHE, while TPV provided updated reproduction heads. Eventually KHE would take over the construction of the top end components as well. The new subsidiary would be (cheekily) named HRD - for Horner Race Development.

The basic elements of the classic Vincent motor were retained – unit construction cases and internal oil passages of the B and C series bikes, as well as the 50 degree cylinder angle of those later models (Series A bikes had separate gearboxes and a narrower 47.5 degree vee). Like all Vincents the engine was air cooled and operated 2 overhead valves per cylinder via rocker arms driven by external pushrods. The trademark Vincent chassis design would be retained as well - Ken would continue to use the engine as a stressed member with a cantilever rear shock and minimalist box-section spine.

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The Period 5 category 1300cc racer.

Everything was updated aside from the basic elements of the design. Modern metallurgy, casting and milling allowed far stronger construction than was possible in the mid 20^th century. Modern engine tuning techniques, with technology borrowed from Australian V8 Supercars and American NASCAR, would also allow for some competitive increases in power, while the stronger components would keep things in one piece on the track. Not worrying about dedication to the original nuts and bolts of the design (it’s a high performance replica, not a concours restoration) meant that KHE could push the performance envelope. Hard.

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Goodwood 2012

The Vincent’s original 998cc Rapide engine had produced 45 hp. The Black Shadow upped the ante to 55 hp. The racing-spec Black Lightning supposedly had around 70 hp.

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The first complete Irving-Vincent, displacing 1299cc via a 92x97.7mm undersquare design with a sky-high 14:1 compression ratio to run on a methanol mix, debuted in 2003 at the Geelong Speed Trials with around 135 hp. It also stumped out an impressive 110 lb/ft of torque. And that was only the beginning. KHE was just getting warmed up.

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Subsequent developments punched out the motor to 1571cc with a 100x100mm square ratio. Now the Irving-Vincent was knocking out 165 hp (at a leisurely 6500rpm) and 130 lb/ft. The latest version, featuring a four-valve, fuel-injected 1600cc engine (still with traditional pushrods but now operating a double-armed rocker on each side) made a staggering 186 hp, with a slightly higher rev ceiling than the 2-valve. As remarkable as these numbers are, Ken and the gang find them disappointing - they claim the outputs are almost 10% below their targets!

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The Irving-Vincent four-valve head.

The resulting bike is as beautiful as it is incongruous. There are several versions, ranging from semi-vintage to compete in Historic categories (with wire wheels, drums or old fashioned discs, and right-side-up forks) to full on Superbike spec to compete against modern machinery. Here you have that instantly recognizable Vincent lump hanging out in the wind (the external appearance is maintained, even if the the internals are thoroughly modern), surrounded by state-of-the-art chassis components and simple cafe-style bodywork. Semi-dry weight is around 385 pounds, ready to race they are right around 400.  It's reminiscent of an Egli-Vincent, but much more modern - on the Daytona bike each end is suspended by top-shelf Ohlins hardware, with magnesium wheels and massive radial mount AP brakes. And of course the Egli has no chance of keeping up with the staggering performance of the Irving. 

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The most recent evolution of the 1600cc Irving-Vincent, which is supposed to be entered into the upcoming 2013 Daytona BOTT.

A small nose fairing keeps wind off the rider, but the engine is left out in the open with only the (required) oil-catch bellypan obscuring the view of the mechanical bits. Despite the lack of streamlining the 1600cc bikes are capable of nearly 170 mph. The open look is partly due to the retention of the Vincent backbone frame, which in the Irving-Vincent doubles as the oil tank. The result is a remarkable machine that has modern components built around a classic style that is as beautiful as it is functional. It's the dream of many a modern cafe-racer builder to take a vintage mill and build a modern chassis around it. Few do it as successfully as Irving-Vincent, fewer still will make it handle like Ken does, and almost no-one will be able to extract the same kind of performance from a vintage motor as KHE does. And that's not mentioning the spine-tingling sound of an Irving-Vincent, which sounds more like an unmuffled V-4 than a big pushrod twin.    

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Such was the performance of the Irving-Vincent that it quickly outgrew the vintage categories it was eligible to compete in. There aren't many bikes in Vintage categories than can knock out 100 plus horsepower, so the Irving-Vincent quickly dominated the category in Australia despite some stiff competition - Australian vintage categories are far from the gentle lapping of restored machinery we see in North America. Ken was planning on campaigning the Irving-Vincent in a Florida vintage speed trial, but upon examining the competition he quickly realized he would utterly decimate the opposition. There was no contest whatsoever - and no challenge. So Ken scrapped that idea and aimed for a bigger target - the Daytona Battle of the Twins race, where he would compete in the AHRMA Formula 1 unlimited category. He set about preparing a racer with modern suspension, brakes and wheels and a highly tuned version of his Vincent twin.

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Daytona-goers were stunned to discover what appeared to be an honest-to-go Vincent in the paddocks, complete with the traditional black and gold livery. A closer inspection would reveal the modern, top tier engineering present, as well as the subtle "Made in Australia" tag cast into the crankcases - if they didn't notice the Australian flag hanging off the rearsets. Entry 888 was to prove a surprise in many respects. Not many people outside of Australian racing were aware of what Ken was up to, and what his machines were capable of. So here was what appeared to be a 1940s-50s engine hung in a minimalist frame with some high-spec suspension bits bolted to it about to go head-to-head with highly-developed Ducatis, NCRs, and Moto-Guzzis.

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Once it was out on the track, it was clear that the Irving-Vincent was something special. Because damned if it didn't win outright on its first outing at Daytona, against far more "modern" performance machinery. It was a shock to the traditional pecking order and took the crowds by surprise. Not only was it an apparent anachronism, but it was developed, built and tuned by a few guys working independently in Australia. No works team, no big backers, and only a few years of development in club racing on the other side of the world. The Daytona winning bike toured various events and venues, including a high-profile visit to and parade lap at the Goodwood Festival of Speed in 2011 and 2012. Plans were made to return to Daytona with a 1600cc four-valve machine, but so far nothing has come of it. Aside from their high-profile victory at Daytona, Irving-Vincents have successfully campaigned in Australian Superbike Historic and various vintage racing categories, with wins in 2007, 2008, 2009 and 2010.

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Irving-Vincent is still around, operating quietly and developing their bikes in relative obscurity with the odd news update on their website. This isn't a surprise when you consider that it is a sideline for KHE - it is surprising that they find the time to develop and race their bikes as much as they do. They continue to compete in historic racing and stun crowds with their thundering anachronism, a magnificent testament to Phil Iriving's sound design and the engineering prowess of Ken Horner. The Irving-Vincent is indeed a high-profile showcase of KHE's capabilities - so in that regard, mission accomplished.

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Ken and Barry Horner with the 1300cc Period 4 category Irving-Vincent.

Interesting Links

The Irving-Vincent official website.

Alan Cathcart on the Irving-Vincent Daytona winner.
Cycle World on the 4V prototype.
The beginning of the Irving-Vincent project in 1999.

A bit of history about the Irving-Vincent project.

Wiki entry on the original Vincent motorcycles.
A possible return to Daytona in 2013? 

Photoset of the Irving-Vincent.