9f7e9f0f Check of a working gap of bearings


1. On early models of engines at capital repairs it is necessary to establish new inserts. On later models of engines control of a working gap can be executed with use of initial inserts. However it is preferable to use new set as the received results will be more exact.
2. Clear a back part of an insert and the place of its installation in the block of cylinders and covers of radical bearings.
3. Establish inserts on the places. Pay attention that the top inserts of the bearing have a working surface with a flute, and the lower insert has a continuous working surface.
4. The working gap can be checked by two methods.
5. One of methods (which assumes existence of a micrometer for measurement of diameter of openings) consists in installing covers of radical bearings together with an insert on the block of cylinders and to screw them the required moment. Measure the internal diameter of each collected couple of inserts of the bearing. Measure diameter of each radical neck of the crankshaft. Subtract the corresponding diameter of a radical neck of the crankshaft from the measured diameter of the bearing.
6. The second (and more exact) the method consists in using the product known as Plastigage. It is a round plastic core which contracts between an insert and a neck of the crankshaft. After removal of a cover of the radical bearing the deformed plastic core is measured by a special template which is available in Plastigage set. The procedure for Plastigage use following.
7. On the inserts installed in the block of cylinders of the engine install the crankshaft without lubricant. Necks of the crankshaft and inserts have to be absolutely pure and dry.
8. Cut off several pieces of a plastic core of Plastigage (they have to be slightly shorter, than width of the main bearings) and establish them on each neck of the crankshaft.
9. Establish covers with the lower inserts and tighten fastening bolts the required moment. In the course of measurement of a gap by Plastigage method do not rotate the crankshaft.
10. Unscrew a cover of fastening of an insert, remove it and apply the large-scale ruler printed on packing to the deformed plastic core. Comparing width of the deformed plastic core to control width on a large-scale ruler, determine gap size.
11. In end carefully clear traces of Plastigage of material from inserts and the crankshaft.