Bearing selection

1 Big-end bearings for the engines of Fiat Punto described here are available in standard sizes and a range of undersizes to suit reground crankshafts. Refer to your Fiat dealer or engine reconditioning specialist for details.

Refitting

2 Clean the backs of the bearing shells, and the bearing locations in both the connecting rods and bearing caps.
3 Press the bearing shells into their locations, ensuring that the tab on each shell engages in the notch in the connecting rod and cap. Take care not to touch any shell's bearing surface with your fingers.
4 Note that the following procedure assumes that the crankshaft and main bearing caps/lower crankcase are in place.
5 Wipe dry the shells and connecting rods with a lint-free cloth.
8 Lubricate the cylinder bores, the pistons, and piston rings of Fiat Punto, then lay out each piston/connecting rod assembly in its respective position.
7 Start with assembly No 1. Position the piston ring gaps as described in Section 16, then clamp them in position with a piston ring compressor.
8 Insert the piston/connecting rod assembly into the top of cylinder No 1, ensuring that the arrow on the piston crown is pointing towards the timing belt end of the engine (see illustrations).



Insert the piston /connecting rod assembly into the top of cylinder No 1 ..



... ensuring that the arrow on the piston crown is pointing towards the timing belt end of the engine


9 Using a block of wood or hammer handle against the piston crown, tap the assembly into the cylinder until the piston crown is flush with the top of the cylinder of Fiat Punto engine (see illustration).



Tap the assembly into the cylinder using a block of wood or hammer handle


10 Ensure that the bearing shell is still correctly installed. Liberally lubricate the crankpin and both bearing shells. Taking care not to mark the cylinder bores, tap the piston/connecting rod assembly down the bore and onto the crankpin.
11 Refit the big-end bearing cap, tightening its retaining bolts finger-tight at first. Note that the faces with the identification marks must match (which means that the bearing shell locating tabs abut each other).
12 Tighten the bearing cap retaining bolts evenly and progressively to the Stage 1 torque setting, then angle-tighten them to the specified Stage 2 angle using an angle-measuring gauge.
13 Once the bearing cap retaining bolts have been correctly tightened, rotate the crankshaft. Check that it turns freely; some stiffness is to be expected if new components have been fitted, but there should be no signs of binding or tight spots.
14 Refit the remaining three piston/ connecting rod assemblies in the same way.
15 Continue with Fiat Punto engine reassembly.