Mazda Training manual - part 11

Powertrain Engines 

Overview 

 

L1001.4_01026 

 

NOTE:  Some of the components of the Z-type engine are very similar in construction and 

operation to those of the L-type engines. Therefore, this section only describes the 
components which are new or differ from those of the L-type engines. 

 

Curriculum Training 

01-31 

Engines Powertrain 

Cylinder Block 

• 

The cylinder block is equipped with cylinder liners, the coolant jackets of which are open 
towards the top. 

• 

The cylinder block is composed of an upper and a lower part, in which the main bearing 
caps are integrated. Upper and lower cylinder block are matched to each other, i.e. they 
cannot be replaced separately. If one of the components exceeds the specification, the 
cylinder block must be replaced as a complete unit. 

 

L1001.4_01027 

 

1 

Upper cylinder block 

2 

Lower cylinder block 

 

01-32 Curriculum 

Training 

Powertrain Engines 

Pistons 

• 

The pistons of the ZJ engine only have valve recesses on the intake side, whereas the 
pistons of the Z6 engine have valve recesses on the intake and exhaust side.

 

• 

Piston, piston pin and connecting rod are not shrinkage fitted, i.e. the components can 
be replaced separately. 

 

 

L1001.4_01028 

 

1 

Engine front side 

4 

Z6 engine 

2 

ZJ engine 

5 

Valve recesses (exhaust side) 

3 

Dot indicating the installation direction 

6 

Valve recesses (intake side) 

 
 

Curriculum Training 

01-33 

Engines Powertrain 

Crankshaft 

• 

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

• 

The installation procedure for the main bearing shells is the same as on the L-type 
engines. 

 

L1001.4_01029 

 

1 

Upper main bearing shell 

6 

Specified measurement 

2 

Thrust bearing 

7 

Oil bore 

3 

Upper main bearing oil groove 

8 

Crankshaft 

4 

Main bearing cap 

9 

Lower main bearing shell 

5 

Main bearing shell 

10 

Engine front side 

 

01-34 Curriculum 

Training