As you probably already know Eco Tuk B.V. has developed a CleanTech solution for Auto-Rickshaws. You have also probably seen some of our descriptions of the functioning of the LPG-LDI system. However we realise that some people still do not fully understand what the Eco Tuk LPG-LDI system really is about! So Eco Tuk has made a new drawing, which should provide you with a more detailed insight.
The 2-stroke engine in comparison with the 4-stroke engine (regular car engine with valves), only needs 1 rotation (2 piston strokes) to complete a combustion cycle. To make this simple engine construction work, the engine makes use of (static) scavenging ports instead of (dynamic controlled) in- and outlet valves which are used in the 4-stroke.
This 2-stroke engine construction is very simple, cheap and theoretically efficient. Unfortunately there is one big issue. By making use of the scavenging ports, in certain situations the inlet and outlet of the engine can be opened at the same time. Because of the age of most
Auto-Rickshaws, they are often equipped with a simple carburettor which mixes the fuel and air before the combustion chamber. In this particular case, when the in- and outlet are opened simultaneously, the fuel-air mixture can wash directly unburned through the combustion chamber into the exhaust.
This can result in 70% scavenging losses while idling and 30-40% at part-throttle. Furthermore these simple carburettor 2-stroke engines run on petroil mixture, which results in burning/wasting a lot of oil, and causing a lot of pollution.
Eco Tuk LPG-LDI System
Eco Tuk its award-winning LPG-LDI (Liquid Direct Injection) concept, injects the LPG in liquid phase direct in the combustion chamber. Because of this technology, the aspiration of the engine takes only place with air and prevents scavenging losses.
When both the inlet and exhaust are covered by the piston, the fuel is injected into the combustion chamber directly through the injector. By injecting the LPG in liquid phase, the amount of fuel can be controlled very precisely. Furthermore the heat extraction caused by vaporization of LPG, results in a lot of advantages.