http://coolplanet.org/2009/12/22/scooters-cause-smog-in-taipei/ Not just another climate blog Mon, 23 Jan 2012 08:58:20 +0000 hourly 1 http://wordpress.com/ http://coolplanet.org/2009/12/22/scooters-cause-smog-in-taipei/#comment-352 Wed, 17 Mar 2010 19:40:28 +0000 http://coolplanet.org/?p=495#comment-352 I had read back in 2004 or 2005 that Taipei had banned the sale of new two-stroke scooters. Is this ban in effect?

]]> http://coolplanet.org/2009/12/22/scooters-cause-smog-in-taipei/#comment-265 Sat, 02 Jan 2010 09:28:06 +0000 http://coolplanet.org/?p=495#comment-265 It helps a lot that the fuel is finely atomized because it is injected with compressed air. But the main reason the Envirofit kits stop so much pollution is related to a big problem with two-stroke engines…..
they send a large portion of the gasoline out the tailpipe, unburned. Two-strokes don’t have valves. They have ports….holes in the side of the cylinder. As the piston goes down, forced by the explosion of gasoline, it passes the exhaust port and the hot gases go out the exhaust pipe. Continuing down, the piston passes the intake port, and gasoline mixed with air enters the cylinder. BUT, the exhaust port is still open, and some of the fuel goes out that port as the piston rises. Envirofit solve this by injecting all the fuel into the cylinder after the piston rises far enough to close all the ports, so no fuel escapes. It makes a huge difference in the amount of pollution.

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