4.2.19. Installation to the place of assemblies of pistons with rods and measurement of a gap in the bearing of the lower head of a rod

Choice of inserts of bearings of the lower head of a rod

Inserts of bearings of the lower head of a rod are subject to classification depending on their thickness (address the Section Survey of Radical Bearings and Bearings of the Lower Head of a Rod). Pay attention that at the 2nd repair installation of inserts of various thickness for ensuring the required gap size in the bearing is possible. Begin the procedure with installation of two thinnest inserts, then if the gap was too big, establish 1 thick and 1 thin insert and again check a gap. In case the gap is too big again, establish 2 thick inserts.

Measurement of a gap in bearings of the lower heads of rods

The gap can be measured in two ways.

The first method assumes installation of covers of bearings of the lower heads of rods on the corresponding rods before installation of pistons in the block of cylinders, at the same time inserts of bearings have to be established on the places. After tightening of fixing nuts of covers of bearings the required effort, by means of an internal micrometer or a caliper measures the internal diameter of each bearing assembly. After measurement of diameter of each corresponding neck of the crankshaft, the second is subtracted from the first value and gap size in the bearing of the lower head of a rod will be result.

The second, more exact method, assumes use of the plastic measuring instrument (address the Section Installation to the place of the crankshaft and measurement of a radial gap of radical bearings) after installation of pistons in the block of cylinders. Following describes the last method along with installation of pistons in the block of cylinders.

 PERFORMANCE ORDER

1. Install the block of cylinders or sideways, or for the end turned to a flywheel / to a driving disk.
2. Spread out assemblies of pistons and rods one after another with the corresponding bearing inserts, covers of rods and nuts.
3. Clear backs of inserts of bearings and a bed of bearings, both in a rod, and in a rod cover. In case new inserts are established, make sure that from them all traces of protective lubricant by means of kerosene or other solvent are removed.
4. Establish inserts of bearings on the places, having made sure that ears of each insert entered deepenings in rods and covers of bearings. Try not to touch with fingers working surfaces of inserts. If for check old inserts are established, you Watch that they were established on the former places.
5. Grease mirrors of cylinders, pistons and piston rings with pure motive oil, Then spread out on their positions of assembly of pistons with rods. Do not grease inserts of bearings at this stage.
6. Begin with assembly No. 1. Make sure that all procedures described in the Section Installation to the place of piston rings are done with piston rings, then establish rings on the places by means of the tool for compression of piston rings.
7. Insert assembly of the piston with a rod into the top part of the 1st cylinder. Make sure that the notch or an arrow indicates the bottom of the piston on the engine towards a distributive chain forward.
8. Rest wooden whetstone or the handle of the hammer against the piston bottom, slightly tapping, insert assembly into the cylinder until the bottom of the piston does not appear aflush with the top edge of the cylinder. You watch to scratching a cylinder mirror bolts of a cover of the lower head of a rod.
9. The first crank has to be in the lower point of the course at present; put on a rod a neck, tapping with the hammer handle by the top part of the piston.
10. Lay plastic thread of the measuring instrument on a crankshaft neck.
11. Establish into place a cover of the lower head of a rod, watching that the tags made on a cover were properly located. Tighten nuts of a cover of the lower head of a rod with the required effort. You watch to breaking thread of the measuring instrument and not to turn the crankshaft in the course of tightening of nuts.
12. Investigate assembly, then by means of the scale printed on packing of the measuring instrument, determine gap size in the bearing of the lower head of a rod.
13. If the gap considerably differs from the value given in Specifications, can be established inserts of bearings of the wrong size
(or excessive wear of old inserts takes place in case they are established repeatedly). If necessary, pick up inserts of the required size according to §1. Previously make sure that between an insert, a cover of the bearing or a rod dirt or oil in the course of measurement did not get. In case the crushed plastic thread of the measuring instrument on the one hand is wider, than with another, there is a conicity of a neck of the crankshaft.
14. Push assembly of the piston with a rod of the 1st cylinder in the top part of the cylinder and then establish assembly of the piston with a rod of the 4th cylinder, repeat the procedure of measurement of a gap in the bearing. After installation of pistons of the 1st and 4th cylinder in the top part of cylinders, install pistons of the 2nd and 3rd cylinders on the places and repeat the procedure of measurement of a gap in bearings of the lower heads of their rods.
15. In conclusion carefully remove from necks of the crankshaft and from inserts of bearings traces of the plastic measuring instrument. Use for this purpose a nail, either a plastic, or wooden scraper which cannot damage the surface of bearings.

Final installation to the place of pistons with rods

 PERFORMANCE ORDER

1. Establish a crank of the 1st cylinder in the lower part of its course. Slightly grease a neck of the crankshaft and both inserts of the bearing. Trying not to touch a cylinder mirror, begin to knock assembly of the piston with a rod down the cylinder on a crankshaft crank. Establish a cover of the bearing of the lower head of a rod, tighten fixing nuts by hand. You watch that adjusting ears of inserts of bearings were directed to each other.
2. Tighten fixing nuts of a cover of the bearing of the lower head of a rod evenly in the progressing order with the required effort.
3. Turn the crankshaft. Make sure that it rotates freely; in case of installation of new components at rotation of the crankshaft some resistance can be observed, however there should not be signs of jamming or breakthroughs in separate points at rotation.
4. Establish the remained 3 assemblies of pistons with rods on their cranks in the same way.
5. Establish into place a zabornik of the oil pump / the filter, the pallet of a case and a head of cylinders (see the Part Repair of the engine without its extraction from the car of this Chapter).