New Holland 667TA/EBF, Repair Manual

Page: 39 / 150

2-21
87519804 NA Issued 11-06 Bur
CHAPTER 2 - 667TA ENGINE OVERHAUL
ENGINE REPAIR MANUAL
PISTONS
BS06K024
Figure 2-17
T h e p i s to n c r ow n fea t u r e s a hi g h tu r bu l e n c e
combustion chamber. The underside of the piston
crown is cooled by engine oil delivered by a spray
nozzle installed in the crankcase.
There are three piston ring grooves with different
functions and different geometry.
1st piston ring with trapezoidal (keystone)
section, ceramic chrome plating.
2nd piston ring with torsional conical rectangular
section.
3rd piston ring with double oil ring wiper with
internal spring.
The following reference data is engraved into the
piston crown:
1. Spare part number and design modification
number.
2. Stamping (facing the crankcase front side)
indicating the mounting direction of the piston in
the cylinder bore.
3. Date of manufacture.
4. Stamping indicating 1st recess insert testing.
1
3
2
4