1004E20 ENGINE - DISMANTLE AND RE-BUILD FOLLOWING OPERATION 1004E10 - WASH AND CHECK DISMANTLED PARTS - RE-FIT CYLINDER HEAD AND OIL SUMP - DOES NOT INCLUDE REPAIRS TO CYLINDER HEAD AND AUXILIARY UNIT - Alfa - 156 - eLearn

3239063 - 1004E20 engine - dismantle and re-build following operation 1004e10 - wash and check dismantled parts - re-fit cylinder head and oil sump - does not include repairs to cylinder head and auxiliary unit

) 1. Undo the bolts (1a) and remove the oil cover, flywheel side (1b).

1. Undo the nuts (1a) and remove the timing side rigid engine support (1b).

1. Undo the bolt (1a) and remove the single drive belt tensioner (1b).2. Undo bolts (2a) and remove fixed timing belt tensioner (2b).

1. Unscrew the bolts (1a) and remove the support (1b) complete with mobile timing belt tensioner (1c).

1. Undo the bolt (1a) and remove the engine rpm sensor (1b).2. Undo and remove the engine oil pressure warning light switch.

1. Undo the bolts (1a) and remove the crankshaft front cover oil seal (1b) with the engine oil pump incorporated.2. Remove the gasket.

1. Position the complete front oil seal cover in a vice fitted with protective jaws.2. Using a suitable tool, undo and remove the engine oil filter cartridge.3. Undo the connector (3a) and remove the engine oil filter mounting (3b) with thermostatic valve incorporated.Remove the gasket.4. Remove the crankshaft front oil seal.5. Undo the bolts (5a) and remove the engine oil inlet (5b).6. Remove the gasket.

1. Fit the tool.

	Name	Country
1	Flange	1.820.618.000

Rotate the crankshaft using the tool fitted previously until the cylinder concerned is at B.D.C.2. Undo the bolts (2a) and remove the big end bearing cap (2b).3. Remove the lower big end bearing shell.4. Remove the connecting rod-piston assembly.5. Remove the upper big end bearing shell.Proceed in the same way with the removal of the pistons and connecting rods for the remaining cylinders.

Remove the tool.

	Name	Country
-	Flange	1.820.618.000

1. Check that the crankshaft end float is within the recommended values using a magnetic base fitted with a dial gauge.

	Measurement		Value
1	End float (mm)		0.049 - 0.211

If the end float of the crankshaft is not within the recommended values, when refitting, reface the seat in the cylinder block/crankcase and use suitable oversize thrust washers.

1. Undo the bolts (1a) and remove the main bearing caps (1b).2. Remove the lower main journal half-bearings.3. Remove the crankshaft.4. Remove the upper main journal half-bearings.5. Remove the thrust washers.6. Undo the bolts (6a) and remove the jets (6b) from the crankcase.

Undo the bolts and remove the crankcase from the mounting brackets, then place it on a workbench. Proceed with removal - 1028H60 piston, pin set - replace . Proceed with removal - 1084B18 engine oil pump, removed - check at bench . Drill and remove the water/oil sealing plugs from the crankcase to allow washing of the channels.

Reassembling ( Dismantling

) Wash the dismantled components.Fit the water/oil sealing plugs in the crankcase, using suitable fitting tools.Lubricate all the components for the mechanical couplings using engine oil.Check that there are no superficial cracks or grooves in the cylinder head support surface.Check that the planarity of the cylinder head support surface is within the recommended values; if this is not the case, regrind the cylinder head support surface.

	Measurement		Value
-	Flatness of cylinder head supporting surface (mm)		< 0.1

1. Measure the diameter of the cylinder liners/bores following the diagram illustrated.

	Measurement		Value
1	Cylinder bore diameter (mm)	Category B	82.010 - 82.020
Category C	82.020 - 82.030
Classe A	82.000 - 82.010

Check that the conicity of the cylinder liners/bores is within the recommended values.

	Measurement		Value
-	Cylinder bore taper (mm)		< 0.005

Check that the ovality of the cylinder liners is within the recommended values.

	Measurement		Value
-	Cylinder bore ovalization (mm)		< 0.05

If the diameter of the cylinder liners/bores is not within the recommended values, ream the cylinder liners/bores in accordance with the recommended oversizes.

In the case of reaming, all liners/bores must be the same oversize.

	Measurement		Value
-	Cylinder liner oversize (mm)		0.1

1. Temporarily fit the bearing caps.

The bearing caps have progressive references (from zero to four starting from the front of the engine) which define their fitting position.

1. Tighten the bearing cap bolts (1a) to the recommended torque using the angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	-	-	-	-

	Name	Country
1b	Protractor	1.860.942.000

2. Check that the diameter of the bearing seats is within the recommended values.

	Measurement		Value
2	Main bearing seat diameter (mm)		63.705 ÷ 63.718

Check that the crankshaft lubrication ducts are free from deposits.Check that the diameter of the main journals is within the recommended values.

	Measurement		Value
-	Main bearing journal diameter (mm)	Category B	59.988 ÷ 59.994
Category C	59.982 ÷ 59.988
Classe A	59.994 ÷ 60.000

If the diameter of the main journals is not within the recommended values, regrind them in accordance with the recommended undersize.

	Measurement		Value
-	Main journal diameter undersize (mm)		0.127

Undersizes for bearings above the value mentioned adversely affect the structural strength of the crankshaft (as a result of contact between the tool and the connectors). As far as the above is concerned, if the regrinding requires undersizes above 0.127 mm, the crankshaft must be replaced with a new one ordered from the Parts Dept. The half-bearings used for undersizes above 0.127 mm should no longer be requested from the Parts Dept. (even if the number is still shown).

Check that the diameter of the crankpins is within the recommended values.

	Measurement		Value
-	Crankpin diameter (mm)	Category B	50.793 ÷ 50.799
Category C	50.787 ÷ 50.793
Classe A	50.799 ÷ 50.805

If the diameter of the crankpins is not within the recommended values, regrind them in accordance with the recommended undersize.

	Measurement		Value
-	Crankpin undersize (mm)		0.127

Undersizes for big end bearings above the value mentioned adversely affect the structural strength of the crankshaft (as a result of contact between the tool and the connectors). As far as the above is concerned, if the regrinding requires undersizes above 0.127 mm, the crankshaft must be replaced with a new one ordered from the Parts Dept. The half-bearings used for undersizes above 0.127 mm should no longer be requested from the Parts Dept. (even if the number is still shown).

Check the crankshaft bearings, taking into account that no adjustment operations should be carried out on half-bearings. If there are signs of grooves or seizing, they must be replaced. Fit the half-bearings, making sure that they are scrupulously clean.

If the crankshaft has been reground, fit the new and oversize half-bearings to restore the original tolerance conditions.

Fit the crankshaft in the special housing in the cylinder block/crankcase.1. Fit the calibrated wire (Plastigage) to measure the main journal clearance.

Check one journal at a time without moving the crankshaft.

1. Fit the main journal caps complete with half-bearings.

The bearing caps have progressive references (from zero to four starting from the front of the engine) which define their fitting position.

1. Tighten the bearing cap bolts (1a) to the recommended torque using the angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	-	-	-	-

	Name	Country
1b	Protractor	1.860.942.000

1. Remove the bearing caps fitted previously and, using a suitable graduated measuring instrument (1a), measure the clearance shown by the calibrated wire (1b).

	Measurement		Value
1b	Clearance between crankshaft bearings - main journals (mm)		0.011 ÷ 0.071

If the reading is not within the specified range, replace the main bearing halves with new bearing halves of appropriate size and category.

Measure the clearance at all the bearings, taking care to carry out this operation, one bearing at a time, without ever moving the crankshaft. Check that the inner diameter of the small end bushes is within the recommended limits; if this is not the case, replace the worn small end bush - 1028H58 connecting rod small end bush - replace .

	Measurement		Value
-	Inner diameter (mm)		26.006 ÷ 26.014

Check that the inner diameter of the small end bushes is within the recommended limits; if this is not the case, replace the piston complete with rings, gudgeon pin and bushes.

	Measurement		Value
-	Piston bush bore (mm)		25.999 - 26.004

Check that the outer diameter of the piston gudgeon pins is within the recommended values; if this is not the case, replace the worn gudgeon pins.

	Measurement		Value
-	Outer diameter (mm)		25.982 ÷ 25.987

Fit the seals in the cylinder liner/bore and check that the opening between the ends is within the recommended values; if this is not the case, replace the piston seals.

	Measurement		Value
-	Opening (mm)	1° seal	0.20 ÷ 0.35
2° seal	-

	Measurement		Value
-	Opening (mm)	Oil scraper ring	0.25 - 0.50

Check that the outer diameter of the pistons is within the recommended values; if this is not the case, replace the piston complete with rings and gudgeon pin.

	Measurement		Value
-	Outer diameter (mm)	Category B	81.930 ÷ 81.940
Category A	81.920 ÷ 81.930
Category C	81.940 ÷ 81.950

The measurement should be made perpendicular to the gudgeon pin axis, 9 mm from the skirt lower edge.

1. Check that the end float (1a) between the second piston ring (1b) and the groove in the piston (1c) is within the recommended limits.

	Measurement		Value
1a	Endfloat, 2° ring (mm)		0.050 ÷ 0.090

Check that the end float between the oil scraper ring and the groove in the piston is within the recommended limits.

	Measurement		Value
-	End float (mm)		0.030 ÷ 0.070

1. Fit the caps (1b) on the connecting rods (1a) and fix them tightening the bolts (1c) to torque.

	Fastening	Component	Ø	Value(daNm)
1c	-	-	-	-

Use the tool for angular tightening of the connecting rod cap bolts.

	Name	Country
-	Protractor	1.860.942.000

2. Check that the diameter of the big end is within the recommended values; if this is not the case, replace the connecting rods.

	Measurement		Value
2	Big end diameter (mm)		53.897 - 53.909

Proceed with refitting - 1028H60 piston, pin set - replace . Proceed with refitting - 1084B18 engine oil pump, removed - check at bench . Check that there are no signs of seizing on the flywheel ring gear teeth; if this is not the case, replace it.Fit the engine on the overhauling stand using the mounting brackets.

	Name	Country
-	Brackets	1.861.001.139

Place the jets back in their housings in the crankcase and secure them using the bolts.Place the thrust washers back in their housings in the third bearing support.Main journal half-bearings have been fitted on crankshafts which have been selected so that the matching clearance is optimum.

The crankshaft is supplied,bythe Parts Dept.,without the appropriate half-bearingsfor 'normal' dimension main journals and crank pins; it is therefore necessary to select the main journal half-bearings to be fitted identifying the grade for each main journal and crank pin for the new crankshaft.

The following is needed for selecting the main journal half-bearings: the code number stamped on the flywheel; the paint mark, if present, next to the main journals.Below is an example of the identification of main journal grades.

1 - Crank pin identification number: the number on the left refers to the first timing side bearing; the final 'N' is a code that does not matter for 4 cylinder engines. 2 - Main journal identification code: the first number on the left refers to the first timing side bearing; the final 'N' is a code that does not matter for 4 cylinder engines. 3 - Set of numbers (if present), in groups of two digits, which indicate the dimensions (thousandth part) of the main journals: the first two numbers on the left refer to the first bearing on the timing side.

Only use the codes in the key, all other codes on the flywheel should not be used.

For the identification of the main journal grade, refer to the numerical code for reference 2 in the key.In the case of the example, the numbers 11111N indicate that all five bearings are Grade A (red colour) as described below.A further method for identifying the grade of the bearings is to read reference 3 in the figure (if present).In the case of the example, the number 94 (first on the left) corresponds to the dimension 59.994 for the first bearing on the timing side which identifies Grade A (red colour); the same method can be used for all the other groups of two digits for the same reference 3 (97 - 95 - 95 - 94). MAIN JOURNAL IDENTIFICATIONGrade A main journal (normal), diameter 59.994 60.000 mm, RED paint mark, code number 1 (94 00)*Grade B main journal (normal), diameter 59.988 59.994 mm, BLUE paint mark, code number 2 (88 94)*Grade C main journal (normal), diameter 59.982 59.988 mm, YELLOW paint mark, code number 3 (82 88)*Grade D main journal (0.127mm undersize) diameter 59.867 59.873 mm, BROWN paint mark, code number 6 (67 73)*Grade E main journal (0.127 mm undersize) diameter 59.861 59.867 mm, GREEN paint mark, code 7 (61 67)*Grade F main journal (0.127 undersize) diameter 59.855 59.861 mm, BLACK paint mark, code number 8 (55 61)* (*) Last two numbers (thousandth part) of the dimensions of the main journals.If a crankshaft is being used where the maximum bearing undersize through regrinding is 0.127 mm, then the grade should be selected by measuring the dimensions of the diameter of the bearing with reference to the above. Having defined the grade and colour for each new or reground crankshaft bearing, it is necessary to select the pair and the size for the bearings which should be the same colour as the corresponding bearing; at the Parts Dept. it is possible to go back to the part no. of the pair of half-bearings required. The above is designed to ensure the optimum operating clearance for all bearings.Lastly, we wish to point out that, usually, the clearance between the main journal and the half-bearing, produced by the selection method described above, should be between the following figures: Minimum: 0.011 mm - Maximum: 0.071 mm; this value can be measured, as a final check, using the Plastic Gauge.Place the upper half-bearings back in their housings in the cylinder block/crankcase.Place the crankshaft back in its housing on the crankcase.1. Place the bearing caps complete with lower half-bearings back in their housings.

The bearing caps have progressive references (from zero to four starting from the front of the engine) which define their fitting position.

1. Tighten the bearing cap bolts (1a) to the recommended torque using the angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	-	-	-	-

	Name	Country
1b	Protractor	1.860.942.000

1. Fit the tool.

	Name	Country
1	Flange	1.820.618.000

Rotate the crankshaft using the tool fitted previously until the cylinder concerned is at B.D.C.1. Refit the piston - connecting rod assembly (1a), complete with half-bearing, using the tool (1b).

To select the connecting rod half-bearings, follow the procedure described previously for the main journal half-bearings.

The piston - connecting rod assemblies are fitted in the cylinder block/crankcase so that the discharge on the piston skirt is in line with the oil jet fitted on the cylinder block/crankcase.

Proceed in the same way with the refitting of the pistons and connecting rods for the remaining cylinders.

1. Check the clearance of the connecting rod bearings, using the calibrated wire (Plastigage).

Place the big end caps complete with half-bearings back in their housings.

The connecting rod caps are fitted so that the number stamped on them is facing the same side as the one stamped on the big end (inlet side).

1. Tighten bolts (1a) to the recommended torque using angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	-	-	-	-

	Name	Country
1b	Protractor	1.860.942.000

Undo the nuts and remove the connecting rod caps complete with half-bearings fitted previously.1. Using a suitable graduate measuring instrument (1a), measure the clearance shown by the calibrated wire (1b).

	Measurement		Value
1b	Clearance between big end bearings-Crankpins (mm)		0.016 ÷ 0.070