Assembling the cylinder block of the K4M engine

After the assemblies and parts for assembling the cylinder block have been prepared, we proceed with the assembly.

Assembling the connecting rod with the piston is covered in the article — “Piston assembly”.

Inspection of the block and crankshaft was covered in the article — “Preparation of the block and crankshaft”.

Fitting the piston cooling nozzles

The new nozzles must be carefully pressed into the holes of the cylinder block. This operation is made more difficult by the fact that the nozzles are small and access to the mounting holes is restricted, so we recommend using special tools.

Fit the plate (2) of the Mot1494 tool onto the cylinder block without tightening the two retaining bolts (1) (see Figs. 1 and 2).

When fitting the nozzles of cylinders 1 and 3, the left hole of the support (1) is used, Figure 1.

When fitting the nozzles of cylinders 2 and 4 — the right hole (Figure 2). Everything else is done in the same way.

Fit the drill jig (3) into the plate (2). To centre the plate, the end of the jig must enter the nozzle hole.

• Tighten the two retaining bolts (1).
• Remove the drill jig (3).

Fit the drift (1) in place of the drill jig (see Fig. 3). Insert the nozzle into the drift.

Note. Pay attention to the fitting direction of the nozzle: the nozzle tip must point towards the centre of the cylinder (see the arrow, Fig. 4).

Strike the drift several times with a hammer until the collar (see 2, Fig. 3) of the drift contacts the support.

Check whether the piston crown cooling nozzles are correctly oriented. Mark “А” corresponds to the nozzles of cylinders 2 and 4, and mark “В” corresponds to the nozzles of cylinders 1 and 3 (see Fig. 5).

Crankshaft bearing shells

Reuse of the crankshaft bearing shells is not recommended. In service, hard wear particles become embedded in the soft layer of the shells; such shells subsequently accelerate wear of the crankshaft journals.

Selecting the main bearing shells

The engine is equipped with shells (see Fig. 6) without locating elements (without a guide tab). The shells are fitted using the Mot1493-01 tool.

Dimensions of the main bearing shells

Fitting the shells

• Fit grooved shells into all the cylinder block bearing seats (see Fig. 7).
• Fit grooved shells into main bearing caps 2 and 4, and ungrooved shells into main bearing caps 1, 3 and 5.

At the factory, a guide tool is used to fit the main bearing shells (see Fig. 8). The shell is placed in the tool and pushed inwards until the front edge of the shell stops against the lug of the tool.

Checking the main bearing clearance

When checking the clearance, under no circumstances turn the crankshaft.

• Remove oil residues from the main journals and the cylinder block supports.
• Fit the crankshaft and the crankshaft thrust half-rings on the 3rd support (grooves towards the crankshaft webs).

• Cut several pieces of calibrated plastic wire from the reel (see 1, Fig. 9).
• Lay the wire along the axis of the crankshaft main journals (outside the area of the support lubrication holes).

• Fit the crankshaft main bearing caps into their original locations (see Fig. 10).
• Tighten the crankshaft main bearing cap bolts to the specified torque in the sequence indicated.

The plastic wire will then be crushed — it will fill the entire clearance between the shell and the crankshaft journal.

• Remove the main bearing caps and withdraw the crankshaft from its seats.
• By the width of the flattened calibrated wire, using the specified gauge, determine the clearance between the shells and the main journals (2) (see Fig. 10).
• Check the clearance value, which must be 0.027—0.054 mm.
• Clean the crankshaft and the main bearing shells of residues of the calibrated wire.

Checking the crankshaft axial clearance

• Lubricate the crankshaft main bearing shells with engine oil. Only the surface facing the shaft journal is lubricated.
• Fit the crankshaft.
• Check that the thrust half-rings are present on the 3rd support (the grooves of the half-rings must face the crankshaft webs).

The mating surfaces of the cylinder block support and the No. 1 main bearing cap must be clean, dry and free from oil traces. Excess sealant will be squeezed out when the parts are tightened. Drops of cured sealant entering the oil or coolant may clog certain assemblies and units (engine, radiator, etc.).

• Apply RHODORSEAL 5661 in 1 mm wide beads (see the arrow, Fig. 11).
• Fit the crankshaft main bearing caps, fitting cap No. 1 on the flywheel side (see Fig. 10).
• Tighten the crankshaft main bearing cap bolts in the sequence indicated.
• Check the crankshaft axial movement, which must be:
  • new half-rings: 0.045—0.252 mm;
  • old half-rings: 0.045—0.852 mm.
• Check that the crankshaft rotates freely.

Fitting the connecting rod bearing shells

The engine is equipped with plain shells without guide tabs (see 4, Fig. 12). The shells are fitted using the Mot1492 tool.

• Select the drift (1) according to the engine model (engine model see markings (2)).
• Fit the drift into the groove of the body (3).
• Fit the connecting rod onto the Mot1492 tool.
• Place the upper connecting rod eye onto the support pin and press the rod in the direction of arrow (а).
• Fit the shell onto the drift.
• Feed the drift with the shell into the lower connecting rod eye (b).
• Withdraw the drift from the rod eye and repeat the operations with the remaining rods.
• Fit the connecting rod cap onto the body pins.
• Fit the connecting rod shell onto the drift (с).
• Feed the drift with the shell into the connecting rod cap (d).
• Withdraw the drift from the rod cap and assemble the remaining rod caps in the same way.

Assembling the connecting rods with the pistons and fitting the rings is covered in the article — “Piston-connecting rod assembly”.

Tightening torques of the fasteners

Continuation of the article on assembling the K4M cylinder block — in the next article.