Restorative repair of the cylinder block (Mitsubishi Galant 6)

General information

During the cylinder block overhaul, pistons with piston rings, crankshaft main and connecting rod bearings, timing drive components and oil pump are usually replaced. On OHV engines, the camshaft and valve lifters are also replaced.

If necessary, cylinders are turned/liners are replaced. Cylinder mirrors must be honed without fail.

The crankshaft is usually also subject to turning with subsequent selection of repair bearing liners.

Removal stepped wear on the top of the cylinders

1. Due to the fact that during their working cycle the pistons do not reach the upper edge of the cylinder, at the end of their stroke a step is formed on the cylinder surface, the presence of which interferes with the extraction of the connecting rod and piston assemblies and may cause damage to the new pistons when they are installed in the engine.

2. There are several types of countersinks available for removing stepped wear from cylinders, all of which are relatively inexpensive tools.

3. Turn the crankshaft so that the piston of the corresponding cylinder drops to its lower position.

4. Cover the piston bottom with a protective layer of rags

5. Prepare a countersink and, following the tool manufacturer's instructions, machine the top of the cylinder to remove any stepped wear.

Note: Try not to overdo it and not to damage the cylinder mirror in its working part!

6. Remove the countersink, rags and sawdust resulting from processing.

7. Proceeding in a similar manner, remove the stepped wear from the mirrors of all cylinders.

Disassembly and cleaning

1. Mount the engine on a mounting stand or sturdy workbench. Alternatively, place the unit on a couple of wooden blocks (transmission mating surface down) on the garage floor. The engine position should provide easy access to the connecting rod cap fasteners and allow the crankshaft to rotate. All covers provided by the unit design should be removed from the engine.

2. Remove the timing drive components and cylinder head from the engine. Remove the oil pan and oil pickup unit. If necessary, remove the oil pump drive, balance shafts and auxiliary shafts.

3. Remove traces of stepped wear on the top of the cylinders (see above).

4. Turn the engine over so that the crankshaft is directly accessible. Using a scriber or center punch, mark the connecting rods according to their cylinder assignment. Mark the main bearing caps in the same way.

5. Turn the engine over again, this time with the first cylinder facing up. Turn the crankshaft so that the piston of the first cylinder is at the bottom of its stroke. Loosen the fasteners and remove the cover of the lower connecting rod head of the first cylinder (make sure that the connecting rod bearing shell remains in the cover).



6. Pull the sections of fuel hose onto the mounting studs, thereby protecting the crankshaft journal and cylinder bore from damage during the process of removing the connecting rod assembly.



7. Using a wooden hammer handle, push the connecting rod upwards by approximately 25 mm and remove the upper bearing shell from the bed in its lower head.



8. Continue to gently tap the assembly upward until the piston rings are released from the cylinder.

Attention! If resistance occurs, immediately stop tapping the assembly and make sure that traces of stepped wear on the upper part of the cylinder mirror have been completely removed!

9. Manually remove the connecting rod and piston assembly from the block completely. Insert the bearing shells into the beds, install the connecting rod lower head cover in place, tightening the fasteners lightly.

10. Proceeding in a similar manner, remove the remaining connecting rod and piston assemblies from the block.

Note: When servicing V-engines, first remove the assemblies from one bank of cylinders, then turn the engine upside down with the second bank and remove the remaining assemblies.

12. At this point, the only component remaining in the block should be the crankshaft. Loosen the fasteners evenly in several steps and remove the main bearing caps (with the liners inserted into them).



13. Carefully remove the crankshaft from its seats in the block.

14. Thoroughly clean all removed components. If you are not going to assemble the engine immediately, place the block in a clean plastic bag.

Checking the status of components

1. When checking the condition of the engine block components, some special tools will be required. These tools include:

• Two or three micrometers for measuring the diameters of pistons and crankshaft journals;
• Plunger type dial gauge;
• Machine for assessing the degree of deformation of connecting rods.

2. If you do not have the necessary tools at hand, you should entrust the inspection of the components to car service specialists.

3. Carefully inspect the block for cracks and other mechanical damage. Methods for identifying hidden defects are described in Section Cylinder head refurbishment, dedicated to checking the condition of the cylinder head. It would be best to entrust the inspection of the condition of the block casting to car service specialists.

Engine block

Checking the alignment of the main bearing beds

1. Check the main bearing beds in the block and caps for signs of overheating, scoring, burrs and other mechanical damage. If necessary, have the block reground or replace it. Minor defects can be removed with a fine-tooth file.

2. Check the alignment of the bearing beds in the block using a flatness gauge, placing the latter along the axis of the crankshaft gasket - if play or gaps are detected, the block should also be machined. The main bearing caps should also be bored to the repair size. After boring, the engine should be equipped with new liners of the corresponding repair size.

Checking the flatness of the mating surface of the block

1. The surface of the block mating with the cylinder head, also called the deck, must be thoroughly cleaned with all traces of the old gasket material, carbon and resin deposits completely removed. The check is performed using a flatness meter and a blade-type feeler gauge. First, the degree of non-flatness is assessed along the block's DP, then along both of its diagonals.

2. If the value of non-flatness exceeds 0.076 mm over a length of 15.2 mm (or 0.152 mm over the full length of the mating surface), the cylinder block must be turned.

Cylinders

1. Usually the working clearance of pistons in cylinders is 0.0381÷0.0635 mm.



2. Assess the external condition of the cylinder mirrors and measure them. Measurements are taken using a telescopic bore gauge and a micrometer in three sections and two mutually perpendicular planes. Analysis of the measurement results will help determine the scope of the upcoming restoration work. The ovality and taper of the cylinders should not exceed the permissible ranges. The measurements taken will help determine the size of the piston seat clearances in the cylinders.



3. The upper part of the cylinders is usually worn somewhat more than the lower part, which leads to the formation of a taper. If the taper value exceeds 0.305 mm, the cylinder is subject to turning.

4. In addition, the cylinder walls usually wear more strongly along the piston thrust surfaces, i.e. in the plane perpendicular to the crankshaft axis. This type of wear leads to the formation of cylinder ovality, which should also not exceed the permissible limits (see Specifications).

Crankshaft

1. Wash the crankshaft with solvent, then dry it thoroughly, using compressed air if possible. Don't forget to clean the oil holes with a stiff brush. Then wash them with solvent.

Caution! Wear safety glasses when using compressed air!

2. Check the main and connecting rod journals of the crankshaft for scoring, cavities, cracks and signs of uneven wear. Inspect the entire surface of the shaft for cracks and other damage. To detect hidden cracks, magnetic particle inspection should be used - take the shaft to a car service workshop.

3. Run the edge of a copper coin along the necks - if traces of copper remain on the surface, then its roughness exceeds the permissible value and the shaft must be re-grooved.

4. Use a sharpening stone, file or scraper to remove burrs from the edges of the oil holes.

5. Check the remaining surfaces of the shaft for cracks and other mechanical damage. Hidden cracks are detected during a special inspection at a service station.

6. Use a micrometer to measure the diameters of the main and connecting rod journals of the shaft. Measure the diameter of each journal at several points along its length and perimeter, which will allow you to estimate the value of its taper and ovality, which should not go beyond the permissible ranges (see Specifications). You should also estimate the value of the crankshaft runout - you will need a pair of V-shaped blocks and a DTI meter. If you do not have the necessary inventory, contact a car service specialist for help.



7. If the wear/taper/ovality of the journals exceeds the permissible value, or there is mechanical damage to the surfaces, the crankshaft should be given for turning. After turning the shaft, it is necessary to select new main and/or connecting rod bearing shells of the appropriate repair size.

8. Check the condition of the seal journals on both crankshaft journals. The presence of worn grooves, burrs or scuffs will lead to the failure of new seals in the very near future. In some cases, the journals can be restored by turning and pressing special thin-walled bushings onto them. If this type of restoration is not possible, replace the shaft.

9. Check the condition of the main and connecting rod bearing shells.

Connecting rod and piston assemblies

1. The connecting rod and piston assemblies must be thoroughly cleaned beforehand. The piston rings must be removed.

Note: Piston rings must be replaced.

2. Using a special tool, remove the rings from the pistons - try not to accidentally damage the walls of the latter.

3. Scrape off any traces of carbon deposits from the piston crowns. After the bulk of the deposits have been removed, hand-clean the surface with a wire brush or a piece of fine-grit sandpaper.

Warning! Never use wire drill bits to clean pistons made of soft material and easily eroded!

4. Using a special tool, clean the ring grooves on the pistons. Alternatively, you can use a piece of an old piston ring for this purpose, but be careful not to scratch the bottom and walls of the groove or cut your fingers.



5. After removing the main deposits, wash the connecting rod assemblies with solvent and dry them thoroughly, using compressed air if possible.

Attention! When using compressed air, do not forget to wear protective glasses! Check the patency of the oil return holes in the rear walls of the piston ring grooves, as well as the oil holes in the lower connecting rod heads.

6. If the piston walls and cylinder faces are not damaged or excessively worn, and the engine block has not been machined or replaced, there is no need to replace the pistons. Normal piston wear is shown as vertical wear marks on the thrust surface and a slight slack in the fit of the upper compression ring in its groove. Do not forget that piston rings must be replaced, regardless of their condition.

7. Carefully inspect each piston for cracks in the skirt, around the piston pin mounts and in the ring area.

8. Check the piston skirt thrust surfaces for scratches, the bottom for through holes and burnouts along the edge. The presence of scratches on the skirt can be regarded as a sign of prolonged engine overheating or too early ignition of the air-fuel mixture - check the proper functioning of the cooling system. Burnouts along the edges of the bottom are evidence of detonation. In any case, the cause of the detected violation must be eliminated to avoid relapse. Possible causes of the formation of the listed defects can also be intake air leaks, incorrect air-fuel mixture arrangement, incorrect ignition timing, incorrect functioning of the ignition and EGR systems.

9. Piston pitting in the form of cavities indicates coolant entering the combustion chambers and/or crankcase. Again, make sure that the cause of internal leaks is eliminated.



10. Estimate the size of the lateral clearance of the piston rings in their grooves, for which insert a new ring from the outside into its groove on the piston and measure the remaining clearance with a blade-type feeler gauge. Repeat the measurement at two or three points along the perimeter of the groove. Be careful not to mix up the compression rings (the upper one is different from the second). If the clearance exceeds the permissible value (see Specifications), the pistons must be replaced.



11. Determine the piston seat clearance in your cylinders, subtract the diameters of the corresponding pistons from the cylinder diameters (see above). The piston diameter is measured along the thrust surface at an angle of 90° to the axis of the piston pin and at a specified distance from the bottom. If the piston seat clearance in the cylinder exceeds the permissible value (see Specifications), the block should be re-machined with a selection of new pistons and piston rings of the repair diameter.

12. After trying to rotate the components in opposite directions, evaluate the tightness of the pistons on the connecting rods. The presence of any noticeable play indicates excessive wear of the joint. To correct the situation, the connecting rod and piston assemblies should be delivered to a car service workshop, where the necessary restoration repairs and replacement of the pins will be carried out.

13. The procedure for removing pistons from connecting rods (if necessary) should also be entrusted to auto service specialists. At the same time, connecting rods can be checked for signs of bending, twisting and other deformations using special diagnostic equipment.

Note: Do not remove pistons from connecting rods unless necessary.

14. Check the connecting rods for cracks and other mechanical damage. Temporarily remove the lower head caps, remove the old bearing shells, wipe the beds in the caps and heads and check them for burrs, scoring and roughness. After completing the check, put the liners back in place, install the caps on the lower heads of the connecting rods, and tighten the mounting bolts by hand.

Note: If the engine is being rebuilt to eliminate pin knock, replace the connecting rod assemblies.

Bearings

Checking the status

1. Despite the fact that crankshaft bearings are subject to mandatory replacement during engine overhaul, old liners should be kept for the purpose of careful examination of their condition, the results of which can provide a lot of useful information about the general condition of the engine. The illustration shows examples of typical bearing liners defects.

2. Bearing failure may occur due to lack of lubrication, dirt particles, engine overloads and corrosion. Regardless of the nature of the defects, the cause of damage to the liners must be eliminated during the engine overhaul to avoid recurrence.

3. For inspection, remove the bearing shells from their beds in the engine block/lower connecting rod heads and main/connecting rod caps and lay them out in the order of installation on a clean work surface. The organized placement of the shells will allow you to link the nature of the detected defects to the condition of the corresponding shaft journals.

4. Dirt and foreign particles enter the engine in various ways. They can be left inside the block during assembly, or penetrate through filters or the crankcase ventilation system. All particles that enter the engine oil eventually end up in the bearings. Metal filings, formed during the normal operation of internal engine components, often become embedded in the soft material of the bearings. There is a high probability of the presence of traces of abrasive in the bearings, especially when due attention was not paid to cleaning the block after the completion of the engine overhaul. Regardless of the method by which foreign particles enter the engine, they are highly likely to end up embedded in the soft surface of the crankshaft bearing shells and are easily detected during a visual inspection of the latter. Large particles are usually not retained in the bearings, but leave noticeable traces on their surface and the surface of the shaft journals in the form of scratches, cavities and scuffs. The best guarantee against such troubles is a responsible attitude to cleaning components after the completion of a major engine overhaul and careful observance of cleanliness during assembly. Frequent regular changes of engine oil also allow you to significantly extend the service life of bearings.

5. Oil starvation can be a consequence of several different, but often interrelated phenomena. Thus, engine overheating leads to dilution of the engine oil and its displacement from the working clearances of the bearings. Insufficient lubrication of the bearings can be explained by excessive size of the working clearances, as well as by common leaks (internal or external). A common cause of oil displacement from the bearing clearances is constant overspeeding of the engine. Violation of the oil flow (usually associated with improper alignment of holes during installation of components) also leads to a reduction in the supply of lubricant to the bearings. A typical result of oil starvation is complete or local wiping/pitting of the surface layer of the liners from the metal substrate. In this case, the operating temperature can rise to such a level that the substrate acquires a bluish tint as a result of overheating.

6. The driving style of the car owner also has a significant impact on the service life of bearings. Driving at low speed in high gear leads to significant bearing overloads, accompanied by the displacement of the oil film from their working gaps. Such overloads lead to increased plasticity of the liners and the occurrence of cracks in the surface layer (fatigue deformation). In this case, the surface material begins to crumble and separate from the steel substrate. Operating a car in the urban cycle (frequent short-distance trips) leads to the development of bearing corrosion due to the fact that insufficient engine heating entails condensation and the release of chemically aggressive gases. These products accumulate in the engine oil, forming slags and acids. When such oil gets into the bearings, aggressive substances contribute to the development of liners corrosion.

7. Incorrect installation of liners during engine assembly may also be the cause of their rapid destruction. Too tight a fit does not provide the required value of the working clearance of the bearings, which leads to their oil starvation. The result of foreign particles getting under the liners (during their installation) is the formation of elevations, the surface layer of which is quickly wiped off.

8. Balancing and auxiliary shafts can be equipped with ring bearings, the replacement of which should be entrusted to car service specialists.

Honing of cylinder mirrors

1. Before assembling the engine, honing of the cylinder mirrors is mandatory in order to achieve the correct fit of the piston rings on them, ensuring proper tightness of the combustion chambers.

Note: If you do not have the necessary tools at hand or do not want to do the honing yourself, the work can be entrusted to specialists at a car service workshop for a very reasonable fee.

2. Before honing, install the main bearing caps/axle housing (without bearing shells) and tighten the mounting bolts to the specified torque.

3. There are two types of hones for processing cylinder mirrors: a bottle brush type hone and a more traditional surface hone in the form of an attachment with spring-loaded sharpening stones. Both tools provide the necessary quality of processing of cylinder mirrors, although the use of the first is preferable for an inexperienced mechanic. You will also need a sufficient amount of rags, special honing or simply liquid machine oil, and an electric drill as a drive for the honing attachments. Proceed in the following order:

• a) Clamp the hone into the chuck of the electric drill, bring the spring-loaded sharpening stones/rods of the brush attachment together and insert the latter into the cylinder.

Warning! Don't forget to wear safety glasses or a face shield!

• b) Wet the mirror of the cylinder being processed generously with oil, turn on the drill and begin to make reciprocating movements with the attachment inside the cylinder. The speed of the vertical movement of the hone should ensure that a mesh pattern is applied to the surface of the cylinder mirror with an intersection angle of the sides of the mesh of about 60°. Do not skimp on oil and try not to remove more material from the surface of the cylinder walls than is really necessary to achieve the desired result.

Note: Piston ring manufacturers may have their own requirements for the angle of intersection of the sides of the mesh pattern - carefully read the instructions on the repair kit packaging.

• c) Do not remove the hone from the cylinder until the drill has come to a complete stop! Continue to move the hone back and forth until it stops rotating. Once the drill has stopped, squeeze the sharpening stones together and remove the hone from the cylinder. When using a bottle brush type hone, wait until the drill has come to a complete stop, then remove the hone while continuing to manually rotate the chuck in the normal direction.
• d) Wipe the cylinder bore with a rag and proceed to honing the next one.

4. Once the treatment is complete, use a file to remove the chamfers from the upper edges of the cylinders - this treatment is performed in order to avoid difficulties when loading the pistons with the rings on them into the cylinders. Be extremely careful - do not scratch the cylinder bore with the file.

5. Finally, the entire unit should be thoroughly washed with a warm, soapy water solution.

Note: The cylinders can be considered washed when, after passing an oil-soaked white rag over the mirror, no gray residue remains. Do not forget to clean all oil holes and channels with a cylindrical brush, then wash the block with a jet of water under pressure.

6. After washing, dry the block thoroughly and lubricate the machined surfaces with oil to protect them from corrosion. Before assembling the engine, wrap the block in a clean plastic bag.

Assembly

1. First of all, it is necessary to prepare the workplace, paying special attention to the cleanliness of surfaces and the availability of sufficient free space. Take care to equip a place for storing the components to be installed. All parts to be installed must also be thoroughly cleaned and dried.

2. Secure the cylinder block to the mounting block and wash it thoroughly again with a solution of soapy water, paying special attention to cleaning the oil ducts and water galleries. Dry the block, using compressed air if possible, then spray it with an anti-corrosion solution such as WD-40®. Wipe the cylinder faces with a clean, lint-free cloth.

3. Install the release plugs and oil gallery plugs in place.

4. Clean the crankshaft equally thoroughly and proceed to install it on the engine (see below).

Engine assembly procedure

1. Before you begin assembling the engine, make sure you have all the necessary parts, materials and tools, which include the following:

• a) Standard set of locksmith tools;
• b) Torque wrench with 1/2-inch drive;
• c) Piston ring tool;
• d) Piston ring crimping tool;
• e) Short sections of fuel hose for fitting onto the connecting rod bearing cap studs;
• f) Plastigage measuring kit;
• g) Set of blade type feeler gauges;
• h) Fine-tooth file;
• i) Fresh engine oil;
• j) Assembly engine or molybdenum-containing lubricant;
• k) Gasket sealant;
• l) Sealant for fixing threaded connections.

2. To save time and minimize the number of problems that may arise, assemble the engine in the following order:

• Four-cylinder engines
• a) Piston rings;
• b) Crankshaft and main bearings;
• c) Connecting rod and piston assemblies;
• d) Rear crankshaft oil seal;
• e) Balancing assembly of the engine;
• f) Cylinder head with valve tappets;
• g) Camshafts;
• h) Balance shafts with sprockets;
• i) Gas distribution chain;
• j) Oil pump;
• k) Oil intake with mesh filter;
• l) Oil pan;
• m) Intake manifold and exhaust manifold;
• n) Cylinder head cover;
• o) Flywheel/drive disc.
• V6 engines
• a) Piston rings;
• b) Crankshaft and main bearings;
• c) Connecting rod and piston assemblies;
• d) Rear crankshaft oil seal with holder;
• e) Oil pump;
• f) Oil pan;
• g) Cylinder heads;
• h) Camshafts and valve lifters;
• i) Timing belt with toothed wheels;
• j) Timing drive covers;
• k) Cylinder head covers;
• l) Intake manifold and exhaust manifolds;
• m) Flywheel/drive disk.

Installing piston rings

1. Before installing new piston rings, check the clearances in their locks. It is assumed that the lateral clearances of the rings in the piston grooves have already been checked and correspond to the accepted standards (see above).

2. Lay out the connecting rod and piston assemblies with ring sets on the work surface of the workbench. From this point on, each ring set will be rigidly "tied" to its piston. Now you can start measuring the gaps in the ring locks.



3. Insert the upper (No. 1) compression ring into the first cylinder of the engine and align it perpendicularly by pushing it down with the piston crown. The ring should be in the area of the lower limit of the working stroke of the rings in the cylinder.



4. Determine the ring gap using a blade type feeler gauge. The blade(s) of the feeler gauge should slide tightly in the ring gap. Compare the measurement with the Specifications. If the gap is outside the acceptable range in either direction, double check that the rings are not mixed up before taking any corrective action (see below).

5. If the gap is too small, it can be widened by boring with a fine-tooth file (read the instructions for the kit first - not all rings can be processed with a file). Clamp a rectangular file in a vice, then put the ring on the file with the lock so that the end of the latter is inside the circle. Slowly pull the ring towards you, removing excess metal from its ends in the lock. When you reach the end of the file, remove the ring, check the gap again, repeat the procedure if necessary.

Attention! Never push the ring away from you onto the file, as this will cause the edges of the lock to converge and there is a high risk of damaging the metal.

6. Excessive clearance is not a crime if it does not exceed 0.51 mm. Once again, make sure that the purchased ring sets meet the characteristics of the needs of your car engine.

7. Repeat the procedure for the remaining rings (second compression and oil scraper) of the first cylinder piston, then for the rings of all other pistons. Remember that now each set of rings is clearly "tied" to its piston, on which it should be installed.

8. Having checked and adjusted the gaps in the ring locks properly, you can begin to put them on your pistons.

9. The oil scraper (lower) ring is put on the piston first. The oil scraper ring consists of three separate sections. First, insert the spring expander into the lower groove of the piston. If the expander is equipped with an anti-rotation tongue, make sure that the latter gets into the counter-drilling in the piston groove. Now install the lower working section of the ring into the groove. To avoid accidental damage to the working sections of the oil scraper ring, do not use any tool to install them - just insert one end of the section into the groove under/above the expander, press it firmly with your finger and, moving along the perimeter of the ring, insert the remaining part. Lastly, install the upper working section of the ring.


10. After seating all three components of the oil scraper ring in the lower groove of the piston, check the freedom of rotation (sliding in the groove) of the upper and lower working sections.

11. The second (lower) compression ring is installed next. The ring should be installed with the marking facing upwards (towards the piston bottom).

Note: Follow the ring manufacturers' instructions carefully, which are usually printed on the kit packaging. Do not confuse the second compression ring with the first (upper) one - they have different cross-sections.

12. Using a special expander and making sure that the ring is turned with the marking facing up, place it in the middle groove on the piston. Try not to spread the ring lock more than is really necessary for its smooth installation on the piston.

13. Proceed in a similar manner to install the first (upper) compression ring (marked side up). Try not to confuse the upper ring with the second one.

14. Fit rings to all remaining pistons one by one.

Installing the crankshaft

1. Installing the crankshaft is the first step in the actual engine assembly procedure. It is assumed that at this stage the engine block and the shaft itself have already been properly cleaned, checked and subjected to the necessary restoration repair.

2. Turn the engine upside down.

3. Loosen the mounting bolts, remove the main bearing caps/cap assembly. Lay the caps out on the workbench in the order they were installed on the engine.

4. If you haven't already done so, remove the old main bearing shells from their beds in the block and caps. Wipe the beds with a clean, lint-free cloth - they should be spotlessly clean.

Checking the working clearances of the main bearings

Note: Try not to touch the surfaces of new bearings with bare hands to avoid unwanted contact of bearings with traces of oil and chemically aggressive substances that are always present on fingers.

1. Wipe the backs of the new main bearing shells and insert the halves equipped with an oil groove into their beds in the block. Insert the remaining halves of the shells into the corresponding bearing caps. Make sure that the tongues of the shells enter the mating grooves in the beds of the block and caps. The oil holes in the block must also be correctly aligned with the holes in the shells.

Warning! Do not attempt to hammer a non-installable bearing into your bed under any circumstances. Do not lubricate the bearings with anything at this stage!

2. Wipe the bearing surfaces in the block and the crankshaft journals with a clean, lint-free cloth. Check the shaft oil holes for patency and clean them if necessary. Any foreign particles in the oil passages will eventually end up in the bearings.

3. Carefully place the thoroughly cleaned crankshaft into the main bearings of the block.

4. Before finally installing the shaft, it is necessary to check the working clearances in its main bearings.



5. Cut the calibrated plastic wire from the Plastigage measuring kit into pieces slightly shorter than the width of the bearing shells and place one piece of wire along each of the main journals of the shaft, parallel to their axis.

6. Wipe the surfaces of the liners in the covers and install the latter in their regular places. Try not to move the pieces of calibrated wire laid along the shaft journals. Lightly lubricate the threads of the fastening bolts with oil and screw them in, securing the covers.

7. Tighten the cover mounting bolts evenly in several stages to the required force.

Caution! Do not allow the shaft to turn while tightening the fasteners!

8. Remove the bolts and carefully remove the main bearing caps. Stack the removed caps in the order they are located on the engine. Try not to damage the flattened calibrated wire and do not turn the shaft. If any of the caps cannot be removed, gently tap them with a soft-faced hammer to release them.



9. Using the width of the flattened threads as measured on the scale on the Plastigage kit packaging, determine the working clearances of the bearings. Compare the measurement results with the requirements of the Specifications.

10. If the clearance is outside the acceptable range, the wrong size bearings may have been installed. Before looking for new bearings, make sure that no dirt or oil has gotten under the ones installed at this stage. If the calibrated wire is flattened more at one end than the other, this indicates that the neck is tapered.

11. Carefully remove the calibrated wire from the journals, scraping off all traces of it with some not very strong tool (for example, the edge of an old credit card). In extreme cases, you can use your fingernail - the main thing is that there are no scratches or burrs left on the surface of the journals/inserts.

Final installation of the crankshaft

1. Carefully remove the crankshaft from the engine. Wipe the bearing surfaces in the block and lubricate them evenly with a thin layer of molybdenum-containing or engine assembly grease. Do not forget to lubricate the thrust washers as well.

Caution! Try not to let grease get on the backs of the liners!

2. Make sure that the crankshaft journals are absolutely clean, then lubricate (with the same grease or clean engine oil) the surfaces of the journals that contact the seals.

3. Install the rear shaft seal.

4. Wipe and lubricate the bearing surfaces in the block, then place the shaft in its proper place. Install the rear bearing cover, then all the others except the thrust bearing. Tighten the cover fasteners to the required torque.

5. Install the thrust bearing cover, screw in the bolts that secure it and tighten them by hand.

6. Slide the shaft forward, pressing it against the thrust surface of the upper bearing shell. Holding the shaft still, press the thrust bearing cap back to align the thrust surfaces of both shells.

7. While pushing the shaft forward, tighten the cover mounting bolts to the required force.

8. To measure the amount of axial play of the crankshaft, attach a dial gauge to the block, pressing its plunger against the end surface of the front journal of the shaft.

9. Carefully push the shaft back until it stops and, holding it in the pushed position, reset the gauge to zero.

10. Move the shaft forward to the end of its stroke and read the instrument reading.

11. If the measurement result is outside the permissible value (see Specifications), replace the thrust bearing shells and repeat the test. If necessary, take the shaft to an auto service workshop for inspection.

Installation of connecting rod and piston assemblies and checking the size of working clearances in the connecting rod bearings of the crankshaft

Preparation

1. Before installing the connecting rod and piston assemblies, the cylinder walls must be carefully wiped, traces of step wear must be completely removed from their upper edges, and the chamfer must be removed. It is assumed that the crankshaft has already been installed in its regular place in the block.

2. Remove the cover of the lower head of the connecting rod assembly of the first cylinder (make sure that there are factory marks or marks applied during dismantling). Remove the old bearing shells from the connecting rod head and its cover and carefully wipe their beds with a clean, lint-free cloth.

Checking the working clearance of the connecting rod bearing

Note: Try not to touch the surfaces of new bearings with bare hands to avoid unwanted contact of bearings with traces of oil and chemically aggressive substances that are always present on fingers.

1. Wipe the back of the new upper bearing shell and place it in the bearing bed in the connecting rod head. Make sure the oil holes are aligned and that the guide tab of the bearing shell fits into the mating groove in the connecting rod. Do not tap the bearing shell into the bed with a hammer under any circumstances. Do not lubricate the bearing with anything at this stage.

2. Wipe the back of the second bearing shell and place it in the connecting rod lower head cover. Again, make sure that the tongue fits into the corresponding groove. Do not use any lubricant - it is extremely important that the mating surfaces of the bearing and connecting rod remain absolutely clean and dry.



3. Position the piston rings with the locks as shown in the illustration.

3. Place the fuel hose sections on the bearing cover mounting bolts.

4. Lubricate the piston and piston rings with clean engine oil. Place the ring crimping tool mandrel on the piston. Leave the piston skirt protruding from the tool mandrel by approximately 6 mm to allow free insertion into the cylinder. The rings should be crimped flush with the piston forming surface.

5. Turn the crankshaft so that the journal of the first crank is in the BDC position. Lubricate the mirror of the first cylinder with engine oil.

6. With the assembly facing the piston bottom markings forward on the engine, carefully insert the connecting rod into the first cylinder of the block. Insert the piston skirt into the cylinder, pressing the lower edge of the ring crimping tool firmly against the surface of the block.

7. Tap the top edge of the mandrel to ensure that it is pressed tightly against the block along the entire perimeter of the bottom edge.



8. Carefully tap the bottom with a wooden hammer handle and insert the piston into the cylinder, simultaneously directing the lower head of the connecting rod onto the journal of the corresponding crankshaft crank. The piston rings may suddenly jump out from under the tool holder, so constantly monitor the tightness of the pressure on its block. Do not rush, if the slightest resistance occurs, immediately stop tapping the piston. Find out the cause of the jam and eliminate it.

Attention! Do not attempt to push the piston into the cylinder by force under any circumstances - this may result in mechanical damage or destruction of the piston rings!

9. After inserting the connecting rod and piston assembly into the engine, before final installation of the connecting rod lower head cover, the operating clearance of the crankshaft connecting rod bearing should be checked.



10. Cut a piece of calibrated plastic wire from the Plastigage measuring kit, slightly shorter in length than the width of the connecting rod bearing shell, and lay it along the first connecting rod journal of the crankshaft, parallel to the axis of the latter.

11. Wipe the bearing surface in the connecting rod cap and install the cap on the connecting rod. Make sure that the mark on the cap is facing the same direction as the mark on the connecting rod.

12. Lightly lubricate the lower ends of the mounting bolt heads with clean engine oil, screw in the bolts and tighten them to the required torque in three stages.

Note: To avoid the wrench jamming, use a thin-walled socket head. If there is any sign of the wrench jamming between the nut and the connecting rod, lift the head slightly and continue tightening. Do not allow the crankshaft to turn during the entire procedure.

13. Loosen the fasteners and carefully remove the cover from the connecting rod. Try not to damage the flattened piece of calibrated wire.



14. Using the flattened wire width measured against the scale printed on the Plastigage kit packaging, determine the bearing operating clearance. Compare the measurement with the Specifications.

15. If the clearance is outside the acceptable range, check for dirt/oil under the bearing backs in the connecting rod and bearing cap before looking for a different size. Re-measure the journal diameter. If the wire is flattened more at one end than the other, the journal is tapered.

Final installation of the connecting rod and piston assembly

16. Using your fingernail or the edge of an old credit card, carefully scrape off any traces of gauge wire from the journal and/or bearing surface.

17. Make sure both bearing surfaces are absolutely clean, then lubricate them evenly with a thin layer of molybdenum-containing or engine assembly grease. To provide access to the surface of the upper bearing, you will have to push the piston into the cylinder a little - do not forget to put protective hoses on the connecting rod cap bolts to avoid damaging the surface of the shaft journal. Try to prevent the piston rings from jumping out of the cylinder.

18. Return the connecting rod to its place by carefully placing its lower head on the journal of its crank, remove the protective hoses from the bolts, install the cover, and tighten the fastening nuts in three stages to the required force.

Note: Make sure that the marks on the connecting rod cap and its lower head are correctly aligned.

19. Repeat the entire procedure for the remaining connecting rod and piston assemblies.

20. Don't overlook the following important points:

• a) Make sure that no dirt gets on the backs of the bearings and their beds in the connecting rods and caps;
• b) Make sure that each assembly is installed in its own cylinder (even if new components are installed, since the piston ring clearances were adjusted to specific cylinders);
• c) The pistons must be positioned with the marking on their bottom forward along the engine (towards the timing drive);
• d) Do not forget to lubricate the cylinder bores with engine oil before installing the assemblies;
• e) Do not forget to lubricate the bearings before final installation of the covers (after checking the working clearances in the latter).

21. After completing the installation of the connecting rod and piston assemblies, check the freedom of rotation of the crankshaft by turning it several times by hand.

22. Finally, it is necessary to check the axial play of the crankshaft once again (see above).

23. Compare the results of the axial clearance measurement with the requirements of the Specifications. If the clearance was normal before disassembling the engine and the old connecting rod and piston assemblies were used, there should be no surprises. If the clearance value goes beyond the permissible limits after replacing the connecting rods, the latter must be removed from the engine and sent to a car service workshop for appropriate mechanical treatment.