Cylinders — Checking for wear (Scorpio 1)

Theoretically, a new cylinder is perfectly round. The piston's work causes wear on the walls at right angles to the piston pins due to lateral load. This wear occurs mainly in this section of the cylinder due to friction against the piston rings.

An idea of cylinder wear can be obtained by removing the cylinder heads while the engine is still in the car. The first signs of wear can be seen when the piston is in the bottom position in the cylinder and a step can be felt just near the top of the cylinder where the top piston ring reaches. If there is no such step, then the cylinder wear is insignificant and there is no loss due to lack of compression or excessive oil consumption due to wear or damage to piston rings or pistons.

If you have a special micrometer for measuring cylinders, measure the diameter of the cylinder in the plane below the rim, and also the diameter of the hole at the bottom of the cylinder in the same plane. If the difference is more than 0.076 mm, boring is necessary. Likewise, a difference of 0.076 mm or more in the cylinder diameter is a sign of ovality and also requires boring.

If any of the cylinders have noticeable scratches or grooves, it also requires reboring. This usually indicates damage to the piston or rings. If at least one of the cylinders requires reboring, it is necessary to perform this operation on all cylinders and install new pistons and piston rings of the repair size. In cases where the engines have already been rebored to the maximum size, there are cylinder liners (sleeves) that can be installed if necessary. In such cases, the help of a specialized company will be required to perform the reboring process and the corresponding maintenance.

The original source of the publication is on the website [FORDBOOK.RU]