Mazda Training manual — part 9

Powertrain Engines

Pistons

•

The shape of the pistons has been adapted to the requirements of the direct injection
system, i.e. the piston top is recessed to improve the mixture formation.

•

The piston skirt is redesigned due to the modified oil jet valves. In addition, it features a
coating to reduce friction between the piston and the cylinder.

•

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

L1001.4_01018

1

Oil jet release width

Cylinder Head

•

Due to the adoption of the direct injection system the cylinder head is equipped with
installation holes for the fuel injectors.

L1001.4_01019

1

Fuel injector installation hole

2

Combustion chamber

Curriculum Training

01-23

Engines Powertrain

Camshafts

•

The intake camshaft features a trochoid shaped cam, which drives the high-pressure
pump of the direct injection system.

L1001.4_01020

1

Exhaust camshaft

5

Cam heel

2

Thrust collar

6

High-pressure pump drive cam

3

Cam nose

7

Pulse wheel for CMP sensor

4

Cam journal

8

Intake camshaft

01-24 Curriculum

Training

Powertrain Engines

Valve Train

•

The valve train is equipped with a roller chain and respective sprockets to improve
durability.

L1001.4_01021

1

Camshaft sprockets

5

Chain guide

2

Timing chain

6

Crankshaft sprocket

3

Pitch size

7

Chain tensioner

4

Pin

8

Chain tensioner arm

Timing Chain Tensioner

•

The L3-T engine features a modified automatic timing chain tensioner. However, the
operating principle is the same as on the L3 engine.

L1001.4_01022

1 Housing

4 Rack

2 Ratchet

spring

5 Plunger

3 Ratchet

6 Plunger

spring

Curriculum Training

01-25

Engines Powertrain

Valve Timing

•

Due to the modified intake camshaft a different timing plate (SST) is required to verify or
adjust the valve timing.

L1001.4_01023

1

Timing plate (SST)

01-26 Curriculum

Training