General information
Cylinder diameter: 84.56 mm
Piston stroke: 74.17 mm
Displacement: 2494 cm³ (2.5 liters)
Compression at 250 rpm:
- Nominal - 14.0 bar
- Minimum - 9-9 ber
- Maximum difference between cylinders is 1 bar
Oil pressure in a warm engine:
- At 1000 rpm - 1.9 bar
- At 3000 rpm - 3.4-4.9 bar
Cylinder head
Allowable warping is 0.10 mm
Valves and valve springs
Valve Plate Edge Width:
- Inlet - 0.9 mm
- Outlet - 1.0 mm
Valve stem diameter:
- Intake - 5.972-5.984 mm
- Exhaust - 5.965-5.979 mm
Clearance between rod and guide bushing:
- Inlet - 0.025-0.060 mm
- Exhaust - 0.030-0.063 mm
Spring:
- Non-perpendicularity - 1.65 mm
- Length in free state:
- Inlet valve - 44.0 mm
- Exhaust valve - 46.9 mm
Article is based on website data (www.MAZbook.ru)
Camshafts and tappets
Neck diameter:
Rear block:
- Support No. 1
- Intake shaft - 29.97-30.00 mm
- Exhaust shaft - 25.94-25.96 mm
- Supports No. 2, 3 and 4 - 25.91-25.93 mm
- Support No. 5 - 25.94-25.96 mm
Front block:
- Support No. 1
- Intake shaft - 25.94-25.96 mm
- Exhaust shaft - 29.97-30.00 mm
- Supports No. 2, 3 and 4 - 25.91-25.93 mm
- Support No. 5 - 25.94-25.96 mm
Bearing clearance:
- Supports No. 1 and 5 - 0.041-0.08 1 mm
- Supports No. 2.3 and 4 - 0.071-0.112 mm
Height of cams (inlet and outlet):
- Nominal size: 43.55 mm
- The maximum permissible size is 43.35 mm
Shaft axial play:
- Nominal value: 0.051-0.100 mm
- The maximum permissible value is 0.14 mm
Permissible radial runout of the shaft is 0.018 mm
Pusher diameter: 29.96-29.97 mm
Clearance of tappets in bores:
- Nominal - 0.025-0.066 mm
- The maximum permissible value is 0.17 mm
Thermal clearance in valves (only for engines produced since 1998):
- Inlet - 0.25-0.31 mm
- Exhaust - 0.27-0.33 mm
Crankshaft and connecting rods
Crank pins:
- Diameter - 52.94-52.96 mm
- Permissible taper and ellipticality - 0.005 mm
- Bearing clearance:
- Nominal - 0.023-0.043 mm
- The maximum permissible value is 0.080 mm
Axial clearance of the lower connecting rod head:
- Nominal - 0.18-0.33 mm
- Maximum permissible value is 0.40 mm
Root necks:
- Diameter:
- Nominal - 61.94-61.96 mm
- Minimum allowable - 61.93 mm
- Permissible taper and ovality - 0.005 mm
- Bearing clearance:
- Nominal - 0.030-0.056 mm
- The maximum permissible value is 0.064 mm
Shaft axial play:
- Nominal - 0.00-0.28 mm
- The maximum permissible value is 0.32 mm
- Thrust liner thickness: 2.00-2.05 mm
Cylinder block
Permissible warping of the surface under the head is 0.15 mm
Cylinder bore diameter: 84.50-94.52 mm
Pistons and connecting rods
Piston diameter (nominal) — 84.45-84.48 mm
Clearance between piston and cylinder:
- Nominal - 0.030-0.056 mm
- The maximum permissible value is 0.13 mm
Clearances in piston track locks:
- Upper compression ring - 0.15-0.30 mm
- Second compression ring - 0.25-0.30 mm
- Oil scraper - 0.20-0.70 mm
Track clearance in grooves (compression rings only):
- Upper compression ring - 0.020-0.066 mm
- Second compression ring - 0.030-0.066 mm
- Maximum allowable - 0.15 mm
Tightening torques for connections, Nm
Main bearing cap bolts:
- 1st stage, bolts A and B - 23-26
- 1st stage, bolts C - 13-20
- 2nd stage, bolts A - Tighten by 80°
- 2nd stage, bolts B - Tighten by 70°
- 2nd stage, bolts C - Tighten by 60°
- 3rd stage, all bolts - Repeat tightening of 2nd stage
Bolts connecting the upper and lower halves of the crankcase - 19-20
Connecting rod lower head bolts:
- 1st stage - 22-26
- 2nd stage - Turn 90° further
* Other values of tightening torques for connections are given in chapter 2B.