Development Of 4G6 2.0L MIVEC Engine

With the increasing of fuel price and the implementation of vehicle fuel consumption tax, the vehicle with small displacement and good economy will be gradually welcome. Especially, car makers SAME supplies engine using tow kinds of engines. But from fuel consumption of SAME engine, we can only meet requirements for the first stage of the state fuel consumption regulation. We can not meet requirements for the second stage of the state fuel consumption regulation. From 2006 years,new car models seldom use 4G63/4G64 engine. For this reason, we should develop MIVEC engine as soon as possible to substitute and upgrade 4G63/4G64 MPI engine. Although SAME introduces 4G69 2.4L MIVEC from MMC, it cannot satisfy needs of China vehicle market.In this circumstance, SAME and MMC united to develop 4G6 2.0L MIVEC engine. It not only extends product line of SAME, but also learn MMC's developing process,developing experiences and quality control by cooperating with MMC. It lays good foundation for SAME future development.According to the above, we develop 2.0L MIVEC based on 2.4L MIVEC. The differences of 2.0L MIVEC with 2.4L MIVEC are reduced cylinder diameter, lessened combustion chamber, optimized piston and intake manifold. We make determination for the size of vale diameter and intake manifold runner by geometry calculation. We have developed engine which meets requirement by a series of function confirmation test, performance test, durability test.Main work in this thesis includes:1) Engine system parts for 2.0L MIVEC are analyzed, balanced and selected.2) 2.4L engine variable valve mechanism is used to 2.0L MIVEC engine.3) Analysis and confirmation of appropriate compression ratio.4) Valve diameters are analized and confirmed for improving air admission efficiency.5) Intake manifold form is analized and confirmed for improving low speed performance of 2.0L MIVEC engine.6) Piston and piston ring are optimized and analyzed for reducing friction loss.At last,conclusion are as follows:1) After using variable valve mechanism and reducing engine friction loss,it is efficient for raising engine performance and lessening fuel consumption.2) Compression ratio plays an important role in engine performance and fuel consumption. Suitable compression ratio not only can improve engine performance, but also lower fuel consumption.3) Long intake port is good for intake system.4) In some conditions, small valve diameter is better than large valve diameter in engine performance and fuel consumption. We have developed engine which meets requirement of vehicle power performance, fuel consumption level and emission by a series of performance test, durability test, engine cold and hot test, NVH test.