In the article, we will consider the preparation of the cylinder block, crankshaft and piston for engine assembly
Not allowed: cracks, breaks, dents, nicks, crumpling of edges, damage to the thread for more than two turns, the presence of signs of wear and work hardening on the teeth of the sprockets (visual inspection).
Invalid parts: Accessory belt, Timing chain, Timing chain tensioner, Timing chain tensioner boot, Timing chain guide, Cylinder head gasket, Cylinder head bolts, Camshaft dephaser filter , crankshaft pulley bolt, exhaust manifold stud nuts, exhaust manifold studs, oil filter, flywheel bolts, connecting rod cap bolts, crankshaft main bearing cap bolts, crankshaft main bearing shells, connecting rod bearing shells, drive chain oil pump, the oil pump chain tensioner must be replaced.
All sealing parts must be replaced
Cylinder block preparation
Crankshaft main journal bore diameter classes are shown in Table 1
Main journal diameter classes are indicated on the cylinder block, figure 1
The maximum diameter "D" of the cylinders at which the replacement of the cylinder block is required is 78.10 mm.
Measure the cylinder diameter along three belts in the longitudinal and transverse directions, as shown in Figure 2.
The limit size is determined by the most worn cylinder using the NI 50-100-1 bore gauge
Using a straight edge and a set of feelers, we measure the non-flatness of the surface of the cylinder block mating with the head
We measure as shown in Figure 3
The maximum allowable flatness of the surface of the cylinder block mating with the cylinder head is 0.1 mm per 100 mm of length
Checking the booster of the cylinder block
We measure as shown in Figure 4
The maximum flatness of the mating surfaces of the cylinder block booster on the cylinder block side and on the sump side is 0.1 mm per 100 mm length.
Crankshaft
The marking of the size groups of the connecting rod and main journals of the crankshaft is applied on the flange for the installation of the flywheel, Figure 5.
We measure using a micrometer type MK 75-1
Crankshaft journal bore diameter classes
|
Letter on block cylinders denoting diameters indigenous bearings crankshaft |
Hole diameter main journals crankshaft in a block cylinders, mm |
|---|---|
|
A |
51.997 - 51.998 |
|
B |
51.998 - 51.999 |
|
С |
51,999 - 52,000 |
|
D |
52,000 - 52,001 |
|
E |
52.001 - 52.002 |
|
F |
52.002 - 52.003 |
|
G |
52.003 - 52.004 |
|
N |
52.004 - 52.005 |
|
J |
52.005 - 52.006 |
|
K |
52.006 - 52.007 |
|
L |
52,007 - 52,008 |
|
M |
52.008 - 52.009 |
|
N |
52.009 - 52.010 |
|
R |
52.010 - 52.011 |
|
R |
52,011 - 52,012 |
|
S |
52,012 - 52,013 |
|
T |
52.013 - 52.014 |
|
U |
52.014 - 52.015 |
|
V |
52.015 - 52.016 |
|
W |
52,016 - 52,017 |
Crankshaft journal diameter classes are shown in Table 2:
|
Letter, class diameter conrod journals on crank Vale |
Diameters of the connecting rod journals of the crankshaft, mm |
|---|---|
|
A |
39.970 - 39.971 |
|
B |
39.969 - 39.970 |
|
С |
39.968 - 39.969 |
|
D |
39.967 - 39.968 |
|
E |
39,966 - 39,967 |
|
F |
39.965 - 39.966 |
|
G |
39,964 - 39,965 |
|
N |
39.963 - 39.964 |
|
J |
39,962 - 39,963 |
|
K |
39.961 - 39.962 |
|
L |
39.960 - 39.961 |
|
M |
39,959 - 39,960 |
|
N |
39.958 - 39.959 |
|
R |
39,957 - 39,958 |
|
R |
39.956 - 39.957 |
|
S |
39,955 - 39,956 |
|
T |
39,954 - 39,955 |
|
U |
39,953 - 39,954 |
Classes of diameters of the main journals of the crankshaft are shown in table 3
|
Letter, diameter class main journals on crank Vale |
Diameters of the connecting rod journals of the crankshaft, mm |
|---|---|
|
A |
47,978 - 47,979 |
|
B |
47,977 - 47,978 |
|
С |
47,976 - 47,977 |
|
D |
47,975 - 47,976 |
|
E |
47,974 - 47,975 |
|
F |
47,973 - 47,974 |
|
G |
47,972 - 47,973 |
|
N |
47,971 - 47,972 |
|
J |
47,970 - 47,971 |
|
K |
47,969 - 47,970 |
|
L |
47,968 - 47,969 |
|
M |
47,967 - 47,968 |
|
N |
47,966 - 47,967 |
|
R |
47,965 - 47,966 |
|
R |
47,964 - 47,965 |
|
S |
47,963 - 47,964 |
|
T |
47,962 - 47,963 |
|
U |
47,961 - 47,962 |
|
V |
47,960 - 47,961 |
|
W |
47,959 - 47,960 |
We check the radial runout of the crankshaft main journals using a prism, an indicator of the type ICH-10, a tripod ShM-PV-8
Radial runout should not exceed 0.01 mm
Piston preparation and inspection
Pistons are not allowed to have chips and cracks of any nature, burnouts, destruction of partitions
The outer diameter D, figure 5, of the piston, measured at a distance L=10 mm, should be 77.948 - 77.958 mm (micrometer type MK 100-1).
The diameter of the hole for the piston pin should be 19.008 - 19.014 mm (caliper type NI 18-50-1).
Checking the connecting rods
Diameter D, Figure 6, holes for the piston pin in the upper head of the connecting rod should be 18.958 - 18.978 mm (caliper type NI 18-50-1).
According to the diameter of the hole D1 in the lower head, the connecting rods are divided into several classes.
The connecting rod class and cylinder number are marked on the cap and on the connecting rod body.
|
Letter, hole class at the bottom head connecting rod |
Hole diameters at the bottom head connecting rod, mm |
|---|---|
|
A |
43.000 - 43.001 |
|
B |
43.001 - 43.002 |
|
С |
43,002 - 43,003 |
|
D |
43,003 - 43,004 |
|
E |
43,004 - 43,005 |
|
F |
43.005 - 43.00b |
|
G |
43,006 - 43,007 |
|
N |
43,007- 43,008 |
|
J |
43,008 - 43,009 |
|
K |
43,009 - 43,010 |
|
L |
43,010 - 43,011 |
|
M |
43,011 - 43,012 |
|
N |
43.012 - 43.013 |
Classes of hole diameters in the lower head of the connecting rod are shown in Table 4 (bore gauge type NI 18-50-1)
Checking the thickness of the lower connecting rod head
The thickness of the lower head of the connecting rod must be within 18.748 - 18.800 mm (micrometer type MK 25-1).
Checking piston pins
Traces of wear and scuffing on the piston pins after pressing out (visual inspection) are not allowed.
Check the outside diameter of the piston pin.
The outer diameter of the piston pin must be between 18.996 - 18.998 mm (micrometer type MK 25-1).
Check piston pin length.
The length of the piston pin must be within 53.4 mm (caliper type ШЦ-1-125-0.1).
We covered the preparation of the cylinder head in a previous article
