Perkins UA Workshop Manual page 80

4
Note: The large and small end bores must be square and parallel with each other within the limits of +/-
0,20 mm (0.0007 in) measured 130 mm (5.1 in) each side of the connecting rod axis on a test mandrel (A).
To check the connecting rod for bend
In service, initially, three pistons of different heights (High, Nominal and Low) were supplied and one
connecting rod. The connecting rod was identified by an 'X' engraved onto the side of the big-end. The small
end bush was machined concentrically. This was later changed to three connecting rod lengths and one piston
height.
The crown of the piston is marked "std". The small end bush is machined eccentrically. A concentric small end
bush, part number 3112E008 can be obtained, that can be fitted to the original connecting rod and then
machined to obtain the correct length grade, refer to Operation 4-14. Connecting rod kits are also available
with the small end bush fitted and machined to obtain the correct connecting rod grade, refer to the tables
below.
Production grade
letters
A and B
C and D
E and F
Fractured split connecting rods are fitted from engine number U ------U839335G.
Fractured split connecting rods
production grade
letters
A and B
C and D
E and F
Pistons with a larger diameter are also supplied, to be fitted if the cylinder bores are bored oversize. The single
height grade also applies to service pistons that are oversize on diameter. Refer to the relevant Data and
dimensions for "Pistons and connecting rods" on page 20.
The piston height above the top face of the cylinder block will still be 0,38/0,51 mm (0.015/0.020 in).
Note: Always use the full engine number to order new parts. In the factory, the correct piston height is obtained
by the use of six length grades of connecting rod and one piston height grade. The small end bush is machined
eccentrically to obtain the different connecting rod lengths.
68
This document has been printed from SPI². Not for Resale
Service grade
letters
B (High)
D (Nominal)
F (Low)
Fractured split connecting rods
service grade
letters
B (High)
D (Nominal)
F (Low)
130 mm
(5.1 in)
L ± 0,20 mm
(0.007 in)
Fractured split connecting rods
130 mm
(5.1 in)
L ± 0,20 mm
(0.007 in)
Workshop Manual, TPD 1392E, issue 3
700 Series
Kit numbers
ZZ0193
ZZ0194
ZZ0195
kit numbers
ZZ90207
ZZ90208
ZZ90209
Continued