EFEK POINT BREAKER GAP PADA KINERJA MESIN DAN BUANGAN EMISI GAS DARI MESIN PENGAPIAN EMPAT TAK

Abstract

The unperfect ignition caused an air pollution emission. Breaker point is an important part in conventional ignition system of spark ignition engine. Routine inspection and maintenance must be done in order to maintain its GAP ideal dimension. The point breaker gap can change due to wear caused by mechanical friction and electron spark abrasion. GAP dimension indicates the magnitude of dwell angle, and dwell angle indicates the periode of curent flowing to the primery coil of ignition coil. Large primery coil of ignition coil means that periode of curent flowing is long enough to make the magnetic flux occures in the ignition coil become saturated. Saturated magnetic flux will produce high voltage induction in the secondary coil of ignition coil. This research shows that gap dimension of breaker point has significant effect on the engine performance and poisoned exhaust gas emission (carbon monocside). Laboratory experiment has been done to measure the engine performance and exhaust gas emission. The engine used in the experiment is 4 K type of four stroke spark ignition engine, with gap dimession varies : 0,35 mm, 0,40 mm, 0.45 mm, 0,50 mm. The result shows that optimum engine operation is 3000 rpm with point breaker gap dimension of 0,4 mm. In that condition engine produces BHP = 49,40 hp, Btorsion = 11,8 kg-m, BMEP = 11,49 kg/cm²., BSFC = 0,25 kg/hp-hour, and BTE = 25,5 %.. The exhaust gases emision are : CO = 2,9 % vol., HC = 224 ppm, CO₂ = 14,9 %  vol. and O₂ = 0,4 %.vol.