KEY POINTS:
Simon Longdill continues the long-held tradition of Kiwis facing problems - if they can't buy one or find one, they will build one.
Longdill wanted a V8 engine for his Aggressor midget chassis and as the limit for two-valve engines is 2.8 litres and 2.4 litres for four-valve engines, there isn't a commercially built one available.
The 31-year-old has long had a passion for designing and building race machines, gaining an engineering doctorate at university to get the necessary theoretical skills to balance the practical ones he already had.
For a number of years Longdill and a few friends worked on building an advanced racing engine for speedway cars. The team used highly modified Toyota four-cylinder engines with dry sumps. They had varying amounts of success and even built their own car to run the engine in.
By 2006, having to use average equipment was becoming a bind so they decided it was time to up the ante. But the cost of competitive engines from the United States was pretty high. This spurred Longdill to think about building his own engine and a small-block V8 seemed the ideal way to stay under the cc cap but have something with lots of grunt.
Longdill needed to join two four-cylinder engines together but the existing speedway engines had long strokes and small bores which meant the capacity of two of them would be more than the allowed limit. What he wanted was something with four-valve heads that could rev high.
The obvious choice was a motorcycle engine. These are big-bore, short-stroke engines that are highly developed and built to rev up to 12,000rpm. They have excellent combustion and flow characteristics and two of them combined would more than match the power output of $70,000 American top-rated four cylinder two-valve pushrod engines.
Longdill settled on a pair of Kawasaki Z12R engines in the end as a combined unit would develop more horsepower than the American four cylinder unit and because it could rev higher, the torque would be more or less the same.
"They're off a big, powerful bike which tends to get written off," said Longdill. "They're usually low mileage and in good condition."
The first prototype was a 2400cc eight-cylinder, 32-valve engine using the motorcycle cylinder heads. To save time and money it also used many motorcycle components in the bottom end - it had two crankshafts connected to a geared output shaft.
"We machined the engine cases from solid billets of aluminium, along with most of the other key components," said Longdill. "It ran on the dyno and immediately hit all the target numbers I'd calculated, followed pretty quickly by a catastrophic failure of the output gear drive - a huge setback."
Finally they got the engine into the car (again home-built) and headed to the racetrack. The car showed potential with great power and straight-line speed, but the engine was too heavy to be competitive and the car didn't handle that well. On the plus side, there were no engine failures or breakdowns.
"I scrapped the initial design and started again in March 2007," said Longdill. "While the engine top-end was very similar, the rest of the design was all new. Weeks of calculations went into the layout, as well as intense study of the current state-of-the-art in Europe, the United States and Japan.
"The resulting engine was much lighter and more compact, as well as more powerful and capable of operating at higher speed, now over 12,000rpm."
The first testing was flawless - the engine made more power and torque exactly to expectations, as was the final weight. The first tests in the car were good, followed by some shakedowns during racing at Western Springs.
"I knew that as a driver I could not get the full potential out of the equipment, so over the winter arranged for Davey Ray to come over from America and run in our team."
The series got off to an amazing start. Ray quickly got to grips with the unfamiliar car and engine and put in some good early races before qualifying for the feature on pole position. He led the international field from start to finish and took the first international feature win for a New Zealand-designed and built engine.
The rest of the series didn't pan out so well. The team had strong showings at the head of the field each night but were hampered by rough conditions and suspension failures. The only engine-related problem they had all year was an ignition sensor failure.
Only two weeks after the last New Zealand race was the Australian National title in Perth. The first racing on the track was tough as it was a new place, they had few tools or resources and there was a high standard of competition, including many experienced locals and top drivers from the US on their off-season.
"We won our first heat race before suffering a broken driveshaft the next heat," said Longdill. "Unfortunately this would put us out for the night, along with any chances of a good starting position for the final on the following night.
"We started the final 15th out of 24 cars, which seemed pretty bad until things got worse; another car made contact and spun us out on about lap 20 of 40, forcing a restart from last place.
"Over the next 20 laps the car was wound right up and picked off the competition one by one. The load on the engine was great testing - full throttle for most of the lap with rpm dropping to 8000 in the corners and up to 12,000 on the straights. On the second-to-last lap Ray grabbed the lead and went on to win."
The goal now is to travel to the US and take on the best in the world. While some sanctions in the US don't allow V8 midget cars to race, the largest midget race in the calendar is the Chilli Bowl, a next-to-no-rules, run-what-you-bring event in January 2009 that attracts racers and teams from all forms of American racing including NASCAR, Sprint, Outlaws and Indycar.
