Why did you decide to concentrate particularly on a two-stroke engine?
It’s powerful, simple, reliable and robust, and spare parts are easy to find. It also has a long lifetime: the oldest we worked on was 32 years old. But there's a deficit in design: it's very polluting. They could be some of the cleanest engines if designed correctly, e.g. with direct injection. There are millions of them out there. As an engineer, I had to try to enhance them.
What were you aiming for when you developed the kit?
There were several key constraints. It had to substantially reduce emissions without impairing the engine's performance, which is appreciated by its users. It had to be installed without machining the engine crankcase, and with only a basic tool set. Of course, it also had to be affordable for Filipino tricycle drivers.
What made you choose Vigan and Puerto Princesa as the cities to test the kit in?
Vigan was designated as a UNESCO World Heritage Site in 1999. The city depends on its tourist economy, but the local environment, the historic architecture and the residents' health are under siege from air pollution. As the city lacks any significant industry, its air quality problems can be traced to its fleet of 3,000 tricycles. The same applies to Puerto Princesa, one of the main tourism capitals of the Philippines, with a two-stroke fleet of over 2,000. Thus, the retrofit kit could literally clean the air in those cities. This will serve as a useful public relations boost for the kit and allow both regional and national expansion, and beyond.
Envirofit is a non-profit organisation, which receives no direct funding from the University of Colorado. What is your strategy for achieving sustainability?
To reach sustainability, you have to be commercially driven. If you're not, you're not holding the bar high enough for yourself to make an impact. And at the end of the day, we're out there to make an impact that is sustainable. It's not just for a couple of years and then going away, it's not “hit-and-run" development. Our ultimate measure of success is “people, planet, profit”: we aim to increase incomes to achieve sustainable health improvements.
Published in 2008