Mazda Training manual — part 19

Powertrain Engines

Cylinder Block

•

The cylinder block is a conventional construction with separate main bearing caps.

L1001.4_01061

Pistons

•

The piston shape meets the requirements of the common rail direct injection system, i.e.
the combustion chamber is integrated in the piston head.

•

The piston skirt is coated to reduce friction between the piston and the cylinder.

L1001.4_01062

1

Anti-friction coating

3

F-mark (engine front)

2 Combustion

chamber

Curriculum Training

01-63

Engines Powertrain

Crankshaft

•

The crankshaft is equipped with a key for the installation of the crankshaft timing pulley
and the crankshaft pulley.

•

In addition, the crankshaft features a drive gear for the oil pump.

L1001.4_01063

1

Oil pump drive gear

4

Lower thrust bearing

2

Upper main bearing shells

5

Lower main bearing shell

3

Upper thrust bearing

6

Main bearing cap

01-64 Curriculum

Training

Powertrain Engines

Cylinder Head

•

The cylinder head is a conventional construction with separate camshaft bearing caps.

•

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 if their length exceeds the specification

(refer to the workshop manual for details).

•

The leak-off lines for the fuel injectors are integrated in the cylinder head.

NOTE: Always replace the gaskets of the injector leak-off lines when removing them. As the

leak-off lines are located under the cylinder head cover, fuel leaking from the lines
can contaminate the engine oil. This results in oil dilution and hence in engine
damage.

L1001.4_01064

1

Exhaust side

3

Engine front side

2 Intake

side

Curriculum Training

01-65

Engines Powertrain

Camshaft

•

The camshaft is equipped with a key for the installation of the camshaft pulley.

•

The camshaft drives the vacuum pump directly, and the power steering oil pump via a
helical gear.

Valve Actuation

•

The camshaft actuates the valves via roller rocker arms and rocker bridges.

•

The valve clearance has to be measured between roller rocker arm and rocker bridge,
and is adjusted through the adjustment screws of roller rocker arm and rocker bridge
(refer to the workshop manual for details).

NOTE: In order to prevent damage to the rocker bridge an adjustment wrench set (SST) is

required to hold the rocker bridge while loosening or tightening the locknut.

•

The valve clearance has to be checked (and adjusted if necessary) for the first time after
20,000 km or 12 months (whichever occurs first). After that it has to be checked (and if
necessary adjusted) every 120,000 km or 6 years (whichever occurs first).

•

For checking and adjusting of the valve clearances refer to the workshop manual.

L1001.4_01065

1

SST (for loosening / tightening the
locknut)

7 Rocker

bridge

2

SST (for adjusting)

8

Camshaft

3

SST (for holding the rocker bridge)

9

Rocker arm shaft

4

Adjusting screw (rocker bridge)

10

Roller rocker arm

5

Measuring point for valve clearance

11

Locknut (rocker arm)

6

Locknut (rocker bridge)

12

Adjusting screw (rocker arm)

01-66 Curriculum

Training