How to Insert a Piston Into a Chainsaw Cylinder
The purpose of the piston rings
The piston rings, the installation of which will be described below, are designed to exclude the possibility of gas leakage through a special thermal gap, which must be located between the piston and the cylinder itself in order to achieve free travel.
Often the ring is made of cast iron, but they do not lose their elasticity. Such elements between the two aforementioned engine parts are called compression elements. As for other varieties, the lower ring (it is wider than the compression ring) is distinguished by special slots, since its function is to remove excessive amounts of oil that collects on the cylinder walls. That is why it is called oil scraper.
General replacement recommendations
When the exhaust pipe begins to “spit” with blue smoke, then repair of the motor is inevitable. In fact, always, signs of wear of piston parts are also increased consumption of both oil and gasoline. In this case, the compression of the motor is reduced, which makes even diesel unprotected. It follows from this that the right choice of new piston elements is the first priority of any owner of automobile transport and, in the best case, repairs will cost them only. To do this, you also need to install just a couple of new gaskets and a pallet for the block. Other damaged parts will already be identified during disassembly of the motor.
The gap between the groove and the ends is much easier to determine if you put the ring in the same groove and apply a set of probes. It should be no more than one tenth of a millimeter and at least 0.05 mm. Otherwise, this will mean that either the ring or the groove is not suitable in size. The clearance of their locks should also be checked. To do this, such parts of the piston group should be in turn attached to the cylinder in its upper part, and then, using probes, measure the gap itself, which should not exceed 0.6 mm, but should not be less than 0.4 mm.
Видео: How to Insert a Piston Into a Chainsaw Cylinder
To properly start the repair, you need to open the cylinder head. After that, you need to carefully analyze the condition of the parts and decide whether to bore the cylinders themselves or lapping the valves. How to prepare piston rings, how to install them without any difficulties and so on. all this will be described below.
Nevertheless, the installation of piston rings is extremely simple, requiring the maximum possible fit of the grooves to their size. Therefore, at least one old compression part can be broken, since under it during operation a deposit is formed, due to which the installation of a new one will be very difficult. Part of such an old broken part is perfect in order to clean up his past workplace.
This is exactly the moment when the device for installing piston rings is indispensable, since repair work of this type is extremely responsible and making mistakes is simply unacceptable. The elements of the piston group are themselves fragile, so you need to be careful and attentive. The most fragile is considered average. When it is installed, there is a big risk of breakage.
It is very important to observe the correct orientation, as otherwise you will achieve increased oil consumption. Each ring has its own marking with marks, so there should not be any special problems with the correct placement.
The upper piston rings, the installation of which begins first, are marked “TOP” and this side of the marking should be directed towards the piston bottom.
As for such a part of the scraper type, it is installed with the scraper down. Installation of parts with chamfers should be carried out so that these same chamfers "looked" up.
If you are dealing with typesetting oil scraper elements that have a special two-function expander of the spring type, then the upper and middle ones should be installed. After this repair scheme is completed, it is necessary to check the ease of their rotation in the grooves themselves.
Installing pistons in a cylinder
During major repairs, the obsolete cylinder is bored or honed. Also used brand new pistons of repair size and ring elements of the same type, but with a large diameter, followed by their compression. They should be lubricated with oil before installation, so that they easily "sit" in their place. The fit also should not be too tight, since thermal expansion due to heating will cause the piston to jam.
Video “How to put the rings on the piston”
After looking at the record, you will learn how to determine the top of the ring at home and figure out which ring should be in a certain place on the piston.