Tillotson TCT Fuel System

The purpose of this graph is to show the test conditions. This test was done under same conditions. Engine speed was kept constant at 3600 rpm. Started from WOT = 100% and then at 75 – 50 – 25 – 10% load. At last point the dyno is off = zero load. But is have small drag. On each load point the engine was run for few minutes until it got stable, then the data was logged over 2 minutes to get a good average on each load point.

We see in this graph the power performance of the engine in the test. We can see a slight difference in more power for TCT 3.48kW vs. 3.44kW but it is negligible.

To keep a perfect Air Fuel Ratio [AFR] is the key of every good fuel-system. That is what the TCT system can do very well. As we can see here on the graph the TCT has been optimised to the best AFR, without the engine we will lose running stability. The trend line of standard Carburettor is mostly a flat line (Red), around 12.5 to 13 AFR. The TCT is very different as we see on the graph, normally 11.5 to 15 AFR. From point 3 it gets lean to reduce Fuel consumption, CO and HC. This is done by

For a SORE engine, using the TCT is very effective solution to reduce the CO emissions below 50% load. As we can see here in the graph this CAM don’t do it as it is more optimised for 3060 RPM. But above 50% crossover point it then reduces the NOx by running richer, as we see on page 10. Running richer will create more CO. Those points 1, 2 & 3 can be adjusted leaner equal to std. as shown here but that would increase the HC+NOx.

HC graph here shows the level of unburnt fuel in the exhaust. Correct Air Fuel mixture (AFR) has a major role in the results. CH need to be compromised versus NOx Engine design, ignition timing have also big influence. Using TCT will give engine manufactures a great opportunity to take their engines to a new level in design using Tillotson TCT system. As the fuel system play big impact of the engine performance. It is hard to improve engine without having proper fuel system.

NOx is a tricky and nasty emission, as NOx is created by the heat in the combustion process, Mostly formed in the flame front as the mixture is burning, therefore it is very hard to reduce the NOx. Like when having lean fuel mixture to reduce CO and HC, then more heat is generated in the combustion. So at this point we need to have a compromise between HC and NOx. When running above 50% it’s very easy to see a problem because of the large supply of Air in the charge, The only way to reduce