Mazda Training manual — part 28

Powertrain Engines

•

There is no positioning tab for locating the lower bearings in the main journals. For
installing the lower main bearing shells a guide (SST) and two guide studs (SST) are
required (refer to the workshop manual for details).

L1001.4_01146

1

Guide (SST)

2

Guide studs (SST)

Curriculum Training

01-99

Engines Powertrain

Cylinder Head

•

The cylinder head features a bolted on camshaft housing, which comprises an upper and
a lower part. Upper and lower camshaft housing as well as the cylinder head are
matched to each other, i.e. they cannot be replaced separately. If one of the components
exceeds the specification, the cylinder head must be replaced as a complete unit.

•

There are no guide sleeves for locating the camshaft housing on the cylinder head. For
this reason, two guide studs (SST) are required for the installation of the camshaft
housing (refer to the workshop manual for details).

•

The cylinder head gasket is available in five different thicknesses depending on the
piston protrusion. The gasket is marked respectively (refer to the workshop manual for
details).

•

The cylinder head bolts are torque-to-yield bolts, which must be tightened in several
stages (refer to the workshop manual for details).

NOTE: The cylinder head bolts must not be re-used.

L1001.4_01092

1

Engine front side

4

Lower camshaft housing

2

Upper camshaft housing

5

Cylinder head

3 Camshaft

01-100 Curriculum

Training

Powertrain Engines

Valve Actuation

•

The camshaft actuates the valves via roller cam followers.

•

The adjustment of the valve clearance is performed via maintenance-free hydraulic
tappets.

L1001.4_01093

1

Camshaft

3

Roller cam follower

2 Hydraulic

tappet

Curriculum Training

01-101

Engines Powertrain

Valve Train

•

The camshaft is driven by a timing belt, which has to be replaced every 240,000 km or
10 years (whichever occurs first).

NOTE: The timing belt must not be re-used.

NOTE: The timing belt has to be installed with the arrows pointing in the direction of engine

rotation.

L1001.4_01094

1

Camshaft pulley

6

Hole for crankshaft timing peg (SST)

2

Hole for camshaft timing peg (SST)

7

Water pump pulley

3

Idler pulley

8

Tensioner pulley

4

Timing belt

9

Fuel high-pressure pump pulley

5

Crankshaft pulley

10

Hole for alignment of the fuel high-
pressure pump pulley

01-102 Curriculum

Training