How to assemble a VAZ-2112 engine

Engine dismantling was covered in the article «Engine dismantling».

Fault inspection of the engine parts was covered in the article «Engine inspection».

In this article we consider the main points of assembling the VAZ-2112 engine: assembling the crankshaft and cylinder block, fitting the rear oil seal and the oil pump, assembling the piston-rod assembly and fitting the flywheel.

Before assembly, all engine parts must be washed and inspected.

Assembling the crankshaft and cylinder block

1. Before fitting the upper main bearing shells, we clean the piston cooling jets with carburettor aerosol cleaner.
2. We fit the shells into the main bearing seats.

The locating lug of the shell must enter the groove in the seat. In the first, second, fourth and fifth seats (counting from the camshaft drive), fit shells with grooves, and in the third — without a groove.

3. We lubricate the shells with engine oil.

4. We lubricate the crankshaft journals with engine oil and lay the shaft into the main bearing seats.

5. We insert into the grooves of the third main bearing support the thrust half-rings, lubricated with engine oil.

The surfaces of the half-rings with anti-friction coating (on which grooves are machined) must face the crankshaft cheeks.

6. We turn the half-rings so that their ends are flush with the ends of the seat.

7. We fit the main bearing caps in accordance with the marks made on their outer surface (the caps are numbered from the timing belt drive side). The lugs of the upper and lower shells of each main bearing must be on the same side.

8. We start the cap securing bolts without tightening them.

9. We tighten the cap securing bolts to a torque of 69–84 N·m (6.9–8.4 kgf·m).

We tighten the bolts of the third cap first, then those of the second and fourth, then those of the first and fifth. After tightening the bolts, turn the crankshaft — it must rotate freely, without binding.

Checking the crankshaft end play

1. We measure the crankshaft end play. It must be within 0.06–0.26 mm. If the play exceeds 0.26 mm, replace the thrust half-rings.

To measure the crankshaft end play, fit the dial gauge so that its probe rests against the shaft flange. Move the crankshaft fully away from the gauge and set the gauge to 0. Move the crankshaft in the opposite direction. The gauge will show the play value.

At the front (on the crankshaft pulley side) a steel-aluminium half-ring is fitted, at the rear — a metal-ceramic one. The rings are made with nominal thickness and with thickness increased by 0.127 mm. When the crankshaft end play exceeds 0.35 mm, one or both half-rings are replaced (nominal play — 0.06–0.26 mm).

Fitting the rear crankshaft oil seal

1. Using a drift, we press the rear crankshaft oil seal into the retainer as far as it will go.

2. We glue the retainer gasket to the oil seal retainer with consistent grease for ease of assembly.

3. We lubricate the oil seal lip with engine oil.

4. We lubricate the crankshaft flange with engine oil.

5. We slide the oil seal with the retainer onto the crankshaft flange and carefully tuck the oil seal lip in with a pointed stick.

6. We move the retainer with the oil seal along the flange as far as it will go and start the securing bolts.

7. Adjust the retainer so that its upper face coincides with the block face.

8. We tighten the six retainer securing bolts.

Fitting the oil pump

1. We lubricate the oil seal lip with engine oil.

2. Lubricate the oil pump gears with engine oil, pouring the oil through the opening under the oil pick-up.

3. We turn the oil pump gears several times by the lugs of the drive gear.

4. We turn the oil pump drive gear so that its lugs align with the flats on the crankshaft.

5. We glue the sealing gasket to the pump with consistent grease for ease of assembly.

6. Slide the pump with the oil seal onto the crankshaft up to the seat on the shaft. Then, with a pointed stick of soft wood, carefully tuck the oil seal lip onto the shaft journal.

7. Carefully move the oil pump along the shaft as far as it will go and start the securing bolts.
8. Adjust the pump position so that its upper face coincides with the block face.
9. Tighten the six securing bolts to a torque of 8.5–10.0 N·m (0.85–1.0 kgf·m).

Assembling the piston-rod assembly

When assembling the piston-rod assembly, the piston pin, lubricated with engine oil, must enter the piston bore with thumb pressure and must not fall out of the piston when the pin is vertical.

Fitting the piston rings

• we orient the gap of the upper compression ring at about 45° to the piston pin axis;
• the gap of the lower compression ring — at 180° to the axis of the upper ring gap;
• the gap of the oil scraper ring — at 90° to the axis of the upper compression ring gap.

We fit the lower compression ring with the groove («scraper») downwards. If the ring bears the mark «ВЕРХ» or «TOP», we place the ring with the mark upwards. When fitting the oil scraper ring, we place the expander joint on the side opposite the ring gap.

1. We wipe the cylinder bores.

2. We wipe the crankshaft crankpin journals.

3. We lubricate the first cylinder bore with engine oil.

4. We lubricate the piston fitting drift.

5. We lubricate the first cylinder piston.

6. We spread the ring gaps as indicated above.

7. We insert the shell into the connecting rod small end. The lug on the shell must enter the groove in the rod small end.

8. We insert the shell into the connecting rod cap so that the lug on the shell enters the groove in the cap.

9. When fitting the pistons into the cylinders, the arrow on the piston crown must face the timing drive.

10. We insert the piston with the connecting rod into the drift. We point the arrow on the piston towards the oil pump and push the piston in gently with the wooden handle of a hammer. We check the correct position of the connecting rod shells.

11. We lubricate the shells and fit the connecting rod cap in accordance with the marking.

The caps are fitted to the connecting rods so that the cylinder numbers on the cap and on the rod are on the same side.

12. We start the cap securing nuts. In the same way we fit and tighten the caps of the other connecting rods.

13. Tighten the connecting rod cap securing nuts with a torque wrench to a torque of 44–54 N·m (4.4–5.4 kgf·m).

Fitting the flywheel

1. Before fitting the flywheel, we lubricate the threads of the flywheel securing bolts with a thin layer.

2. Fit the flywheel so that the mark on the flywheel is opposite the connecting rod cap of the fourth cylinder, since the securing bolts are arranged asymmetrically.

3. We fit the lock washer and start the flywheel.

4. We tighten the flywheel securing bolts to a torque of 62–89 N·m (6.2–8.9 kgf·m), holding the flywheel to prevent it from turning.

Further engine assembly is covered in the continuation of this topic.