How to correctly set the ignition timing
Before proceeding to an operation such assetting out the ignition, you need to read some definitions. For example, the ignition timing. It is known that at the time when the piston passes the compression stroke, the crankshaft makes half a turn, it turns 180 degrees. This applies not only to the compression stroke, but to all others, so the full cycle of the 4-stroke engine is two turns, or 720 degrees.
There is such a thing as an octane numbergasoline. We will not go into details about how it is measured, it is important that it is different. So, for gasoline with a different octane number, the rate of ignition is very different. If the ignition timing is set exactly when the piston is at the top dead center, ignition will occur even when it goes down under the action of the flywheel inertia.
To prevent this from happening, and explosion of the mixtureoccurred exactly at the top dead center, the ignition timing is set. For example, if the VAZ-2106 piston does not reach the VMT. 4-5 mm, then the crankshaft to the full 180 will not be missing 10 degrees. If the first value is reduced to 2-3 mm, then the second will be reduced to 5 degrees. These are the most common angles that are used when using AI-80 and AI-92, respectively.
Now directly about the ignition setting. Consider this procedure using the example of a contactless system to eliminate problems with the gap in the contacts. First, you need to determine the compression stroke in the first cylinder. This is done with a fleece, which plugs the spark plug in the head, after which the crankshaft rotates slowly through the ratchet. If in the cylinders a good compression, the fleece should fly out at the beginning of the tact.
As a rule, on the crankshaft pulley and on theThe front cover has marks. This is the ignition advance angle. They correspond to the above angles, as well as VMT. in turn, along the course of rotation. The last label usually sets the ignition for AI-95 or AI-98, so the use of this tag is quite rare.
After setting the crankshaft in the desired positionthe labels on the ignition distributor are combined, they differ in different brands and models, and the trampler is inserted into the landing socket, and then fixed.
But I must say, the initially exposed corner of the timing of the ignition may not be final.
A more detailed ignition setting is carried outafter starting the engine, its warming up to normal operating temperature, and also after correct adjustment of the carburettor at idle. For this purpose, a speed of 35-40 km / h is dialed in the third gear, after which the fourth gear is switched on. After this, there should be a short-term detonation, which disappears within five seconds. If it remains for a long time, then it is necessary to turn the distributor body in the direction of rotation of the roller, or vice versa, if there was no detonation at all.
In conclusion, it is worth saying that the wrong angleLeading, especially too early, leads to serious damage to the crank-piston group, such as, for example, loosening the pushers at the top of the connecting rod or the crankshaft neck at the bottom.