Boring an engine - why should it be needed?

In the life of every car owner, sooner or later the moment comes when his iron horse has exhausted all its resources and can no longer serve faithfully and truthfully. Sometimes such troubles are dispensed with without any serious procedures, but it also happens that boring an engine is the only way to bring it back to life. It happens, when only the necks of the crankshaft are subjected to grinding . Such measures are taken in the event of a pressure drop in the lubrication system, and also in the case of a backlash in the lower end of the connecting rod. Still have to replace the liners.

But this is the most innocuous case of engine repair with the use of "surgical intervention". It happens that the engine cylinders wear out, lose their rounded shape and become oval. The longer axis has the direction of rotation of the crankshaft and the opposite to it, since it is in this direction that the greatest stresses on the metal are tested, and therefore, it is here that it is most worn out.

Boring of blocks of cylinders is a wrong, incorrect expression, as the block itself is not boring. This operation is carried out exclusively with the cylinders. All of them have nominal and repair sizes. If the wear is too great, then boring is carried out to the nearest repair size. If the ovality is too large, then two or even three sizes are removed immediately, which, of course, implies replacement of the pistons. The boring of the blocks is carried out by experienced specialists on precise equipment, since the values here are comparable to 0.001 millimeters. One must assume that a simple person from the street can not conduct such an operation. However, even a professional without proper equipment is also not capable of this.

Another case in which it may be necessary to bore an engine is a deliberate increase in the working volume, namely tuning. Of course, 2.5 of the 2-liter engine is not done, but everything is made up of small things. The engine boring is a pretty effective, but not a magical way. Here you need even more accurate equipment, as well as the master-gold hands.

But things are not so difficult and scary. It is possible that not the cylinders, but the piston rings , were worn out . Naturally, the first can not escape it either, but repairs can be limited to the latter, which, of course, is much cheaper.

In order to find out what needs to be repaired, it is necessary to conduct measurements called defect. To determine the wear of the rings, a probe is used, as well as a micrometer or caliper. They measure the thickness of the ring and the distance in the lock, that is, at the junction of its ends. This distance is called the thermal gap and for different engines is different.

The ovality of the cylinders is determined by the holometer, which measures the diameter of the cylinder at six points: three - along the length and perpendicular to the axis of the measurements. Defect is the only sure way to determine if a boring engine is required or not. But here, too, there are small pitfalls that can cause a lot of trouble and problems. One of them is the inaccuracy of the measuring instrument, so you need to select it carefully. If you do not carefully select the required, it is fraught with different sizes in the cylinders after boring, which means that the engine will fail.