4BT Diesel Engine Cylinder liner 6736-29-2110 3904166 For CUMMINS

 
Knock on the cylinder symptom edit broadcastThe symptoms of cylinder knocking in diesel generators during operation are: from medium speed to low speed, there will be a heavy knocking sound, black smoke from the exhaust pipe of the diesel generator set, and sometimes there is a cannon sound or outward fire, and the engine body is overheated. The main reasons for knocking cylinders are:1. The oil supply time is too earlyWhen the piston of the diesel generator set does not move upwards to reach the specified fuel injection position, the injector begins to inject oil, so that the fuel combustion is advanced, and the high-pressure gas in the cylinder hits the piston, emits a rhythmic "click, click" crisp knocking sound, reduce the throttle, and the knocking sound is obvious.The elimination method is to adjust the fuel supply advance angle, that is, increase the gasket between the fuel injection pump and the gearbox to delay the fuel supply time to meet the specified fuel injection time. For every 0.1 mm increase in the gasket, the oil supply advance angle can be delayed by 1.3-1.7.2. Poor fuel burningToo low fuel injection pressure, oil dripping from the injector, poor atomization of fuel injection, and too late fuel supply time will cause poor fuel combustion and cause cylinder knocking. The knocking sound caused by such faults is muffled, hoarse and accompanied by engine overheating, black smoke or exhaust pipe cannon and fire. The injector should be removed for inspection and adjustment, adjust the fuel supply time, and replace it with new parts if necessary to make it comply with the regulations.3. The oil outlet valve is wornAfter the oil outlet valve is worn, on the one hand, the gap between the pressure reducing ring belt and the inner hole of the valve seat becomes larger, the sealing becomes poor, and the pressure reduction effect deteriorates; On the other hand, the residual pressure in the high-pressure oil pipe is too high, and the oil supply increases, causing the fuel to deignite and knock the cylinder. The knock is especially noticeable when the throttle is reduced.Cylinder pulling fault edit broadcastCauses and preventionDiesel engine cylinder pulling refers to the phenomenon that the diesel engine piston assembly and the cylinder working surface interact violently (arising from friction), resulting in excessive wear, hair pulling, scratches, abrasions, cracks or bites on the working surface. Pulling cylinders is produced under lubricated conditions with varying degrees of adhesion wear. When the cylinder is light, the cylinder liner and piston assembly are damaged, and in serious cases, it will cause malignant damage accidents of biting the cylinder. And pull off the piston or connecting rod, break the machine, so as to cause a major accident. Therefore, it is of great significance to analyze the formation mechanism of diesel engine cylinder fault, find out early prediction and correct countermeasures, correctly manage and use diesel engine, improve reliability and extend service life, and improve the ability of management personnel to eliminate faults. Reasonable use and attention to maintenance (regular inspection) also achieve to reduce diesel engine cylinder failure.1. Cylinder pulling phenomenon:Most of the mechanism of cylinder damage is due to the local destruction of the lubricating oil film of the sliding part, at which time the metal contact occurs first in the protruding parts of the two relatively moving surfaces, and then a small "smelting phenomenon" occurs locally, and the sintered part is torn due to the relative movement of the parts. In this process, the metal surface becomes a hardened layer, and when the hardened layer is destroyed, the resulting metal abrasive particles will become the gluten that aggravates the surface wear. In a short period of time when the so-called "burn wear" occurs, uneven wear marks on the surface of the piston and cylinder liner parallel to the cylinder centerline appear is the cylinder pulling phenomenon. In severe cases, the sliding part is completely stuck or stuck, and may even produce cracks in the weak parts of the two surfaces, resulting in the destruction of the machine, ie