Page 54 - E BOOK ENGINE MECHANICAL M2

2. TECHNICAL FEATURES OF 4D56 ENGINE

(9) Camshaft
A main gear and a sub gear are placed to a drive the
scissors gear mechanism of the camshafts to reduce
the noise. When a load is applied in the direction in
which the sub gear has no backlash, it greatly reduces
the gear backlash sound.

Fig. 2-9

(10) EGR Cooler
Multi-layers type EGR cooler is used to improve the
EGR cooler efficiency.

Fig. 2-10

(11) Drive Belt
A Serpentine belt drive is used, which is a maintenance-
free and drives all accessories using one V-ribbed belt.

Fig. 2-11

3. KNOWLEDGE CHECK
Regarding the following sentences of 4D56 engine, identify which ones are correct or incorrect, and
make the required correction to the wrong portion of the incorrect sentence.
(1) In the cylinder block the sleeve of the cylinder liner is adopted.
(2) A deep bowl type combustion chamber is provided on the top of piston.
(3) A SOHC 4 valve construction is used.
(4) Lightweight rocker arm to be made of steel plate and the roller follower are adopted.
(5) The scissors gear mechanism for drive gear is provided at the exhaust camshaft sprocket.

2 - 3 Pub. No. PTAE1228