Ironically, one group that really knows the ins and outs of motorcycle engines are the car boys from the National University of Singapore (NUS).

How so?

Well, for the last six years, the mechanical engineering undergrads have been building formula-style cars for competition using only motorcycle engines.

They use motorcycle engines to save weight, as competition rules only allow engines of 610cc or less. Also, the engines are race-ready and lighter.

The cars are used to take part in the prestigious Formula Society of Automotive Engineers (FSAE) competition, which is held in the United States in May each year.

In it, more than 100 university teams worldwide compete by designing, fabricating and racing the cars they have built.

In 2001, the pioneer NUS team developed its first race car using a single cylinder Yamaha XT 600 engine. But that engine was not competitive enough. The team needed more power and speed.

And as their knowledge evolved, so did the motorcycle engines they used. The team, under the guidance of faculty advisor Associate Professor Seah Kar Heng, have been using higher-revving 600cc in-line four engines.

The engine they used for the 2007 FSAE was the fuel-injected Honda F4i. But installing a motorcycle engine into a race car is not a "plug and play" affair.

Said Mr Chen Guoxian, 25, who is in charge of the car???s powertrain and engine systems: "Fitting a motorcycle engine into the car opens up more challenges for the team. "The engine is essentially built for a motorcycle. So a few modifications are needed to make the engine complement the car???s design."

CUSTOM MADE

From their studio at the mechanical engineering faculty, where bits of carbon fibre mix with a hint of petrol in the air, the students grappled with the challenges.

First, the motorcycle engine was redesigned to take lateral acceleration. When turning a corner, the G-forces will slosh around the lubrication needed to feed oil to other moving parts in the engine. This sloshing effect may cause the oil pump to suck air instead of oil, said Mr Chen.

Second, the engine was re-wired by removing signal and brake lights. Sensors, measuring oil pressure, air/fuel ratio and vehicle speed were added.

A Power Commander was also installed for precise fuel mapping. What the boys couldn???t buy off the shelves, they designed and fabricated themselves.

The F4i???s heavier steel radiator was replaced with a lighter, aluminium one. The NUS team also burned the midnight oil - creating intake and exhaust manifolds, and their own shallower oil sump.

Said Mr Chen: "We designed a shallower oil pan with the same volume as the original so that the engine can be mounted lower, thereby lowering the car???s centre of gravity (so it will roll less in corners)."

To simulate the stresses the car would have to endure in a race, the motorcycle engine was also dyno-tested.

EXTREME

Said team member Andre Oh, 24: "I occasionally service my own motorcycle, but the kind of work we did on the race car engine was extreme... It was made to produce more speed, torque and performance."

The result of the year-long project experienced only by selected engineering students is a 200kg race car capable of 0 to 100kmh in less than four seconds.

The NUS team is the only group in Singapore given permission by the authorities to build a race car for competition use. The best position it has attained is 27th, in the 2006 FSAE race.

But last months??? 2007 FSAE competition in Michigan was a disappointment for the team.

All because of damaged gears sustained during a practice session. As a result, the team was not able to compete in some parts of the competition and came in 78th.

Said Mr Chen: "I was disappointed, but it???s part and parcel of racing. We can???t be perfect, but we know we did the best we could." Still, the team, which has already started work on next year???s car, remains optimistic.

Said Mr Oh: "We have learnt many lessons from this experience. Highly-tuned race engines are not meant to last for a long time - just enough for a race.

"For next year???s car, we need to fine-tune the engine and make it more reliable. We also need to keep the racing spirit alive."