Irving Vincent 1300 Two-Valve Racer
Here is a bike well known to Aussie race-goers, although possibly not as well recognised elsewhere – the Irving Vincent.
Seen here in 1300 cc form at the 2016 Phillip Island Classic. The Horner brothers have built at least 18 of their machines (including sidecars) over the years to compete in various categories of classic racing.
Since 2003, Ken and Barry Horner have been constructing their Irving Vincents completely in-house at their company KH Equipment in Melbourne.
The company manufactures starters for the mining industry (mainly) so access to all the best casting, milling and CNC equipment was not a problem!
Design planning began in 1999. Ken and Phil Irving had many conversions dating back to the ‘70s on the “modernisation” of the Vincent and permission to use the ‘Irving’ name was obtained from Phil’s widow after his death in 1992.
Since that 2003 debut at the Geelong Speed Trials, Irving Vincents have competed around the world with victories at Daytona (Battle of the Twins) in 2008 and the Goodwood Festival of Speed in 2014. Not to mention many, many wins on home soil.
Perhaps the most surprising thing about the bikes is that the Horners have managed to raise the original Vincent ’s 55 hp to 186 hp (in 1600 cc 4-valve form) while still keeping the appearance of that famous motor basically intact. The internals are another matter entirely!
A lot of technology and design experience from NASCAR and V8 Supercar engines has made its way into the motor, particularly in the areas of cam profiles and combustion chamber shape.
A three-gear primary drive, far more efficient lubrication system, five-speed drum-selected gearbox, new cylinder heads and MoTeC electronic ignition system are only a few of the hundreds of changes made to the basic 50º V-twin’s design.
The 1300 cc two-valve Period 5 bike I photographed has a 13:1 compression ratio, 100 x 82.55 mm bore x stroke and makes 160 hp at 7000 rpm. Torque is 125 ft-lb at 6000 rpm.
A modern chrome-moly steel version of the Vincent’s spine frame holds 3 L of oil and is used in conjunction with a cantilever rear shock. Again as per the original the engine is a stressed member.
Apart from the bike’s results probably the biggest impact it has on those who have been lucky enough to watch it race is the absolutely glorious noise it makes!
Irving Vincent 1300 Two-Valve P5 Racer Specifications
| Irving Vincent 1300 Two-Valve P5 Racer Specifications | |
| Engine | 1300 cc two-valve |
| Bore | 100 mm |
| Stroke | 82.55 mm |
| Compression Ratio | 13:1 |
| Max Power | 160 bhp @ 7000 rpm |
| Torque | 125 ft-lb @ 6000 rpm |
Irving Vincent P5 Racer Gallery
