BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car



BMW E30
+ 1. Maintenance instruction
+ 2. Maintenance
- 3. Engine
   + 3.1.2. Specifications
   - 3.2. Dismantle and capital repairs of the engine
      3.2.2. Specifications
      3.2.3. Capital repairs – the general instructions
      3.2.4. Check of a compression in engine cylinders
      3.2.5. Capital repairs – general comments
      3.2.6. Diagnostics of the engine by means of the vacuum gage
      3.2.7. Capital repairs – alternatives
      3.2.8. Dismantle of the power unit
      3.2.9. Removal and installation of the engine
      3.2.10. Order of dismantling of the engine
      3.2.11. Dismantling of a head of the block of cylinders
      3.2.12. Cleaning and check of a head of cylinders and details of the valvate mechanism
      3.2.13. Repair of valves
      3.2.14. Assembly of a head of the block of cylinders
      3.2.15. Removal of pistons and rods
      3.2.16. Dismantle of the crankshaft
      3.2.17. Intermediate shaft (only M20 engine)
      3.2.18. Cleaning of the block of cylinders
      3.2.19. Check of a condition of the block of cylinders
      3.2.20. Honningovaniye of cylinders
      3.2.21. Check of a condition of pistons and rods
      3.2.22. Check of a condition of the crankshaft
      3.2.23. Check of radical and conrod bearings
      3.2.24. Engine assembly order
      3.2.25. Installation of piston rings
      3.2.26. Installation of an intermediate shaft
      3.2.27. Installation of the crankshaft and check of gaps in radical bearings
      3.2.28. Installation of a back epiploon
      3.2.29. Installation of rods and pistons, check of gaps in conrod bearings
      3.2.30. Launch of the engine after repair and a running in
   + 3.3. Engine electric equipment
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Useful tips




3.2.2. Specifications

GENERAL INFORMATION

All sizes are specified in mm.

Compression pressure in cylinders  10 – 11 kgfs/cm2
Maximum permissible deformation of the demountable plane of a head of cylinders 0,1 (except M40, for M40 – no more than 0,03)
Extreme height of a head of cylinders after grinding, not less, than a mm:
  – M10 128,6
  – M20
124,7
  – M40
140,55
Valves
Diameter of a core of the valve (standard):
  – M10
8,0
  – M20
7,0
  – M40  
     • Inlet
6,975
     • Final
6,960
Corbel width, limit
  – Inlet
1,191
  – Final
1,980
Side side play of a core of the valve (see subsection 3.2.13) 0,787
Valve head facet corner
45 °
Cam-shaft and yokes of valves:
  – A gap in basic necks  0,033 – 0,076
  – Axial side play:
     • M10
 0,02 – 0,13
     • M20 no more than 0,2
     • M40  0,065 – 0,150
  – A gap between the roller and a yoke ("a radial gap")  0,015 – 0,051
Crankshaft
Axial side play:
  – M10
 0,085 – 0,174
  – M20 and M40
 0,080 – 0,163
Diameter of radical necks (standard):
  – M10
     • red marking  54,98 – 54,99
     • blue marking
54,97 – 54,98
  – M20
     • red marking  54,98 – 54,99
     • blue marking
 59,97 – 59,98
  – M40
     • yellow marking
 59,984 – 59,990
     • green marking
 59,977 – 59,983
     • white marking
 59,971 – 59,976
Repair sizes of necks
0,25; 0,50; 0,75
Gap in radical bearings:
  – M10 and M20
 0,030 – 0,070
  – M40
 0,020 – 0,46
Diameter of conrod necks (standard):
  – M10 and M20
 47,975 – 47,991
  – M40
 44,975 – 44,991
Diameters of conrod necks (repair) 0,25; 0,50; 0,75 (on a part of engines)
Rods
Axial side play
0,041
Gap in conrod bearings:
  – M10
 0,030 – 0,070
  – M20
 0,020 – 0,055
  – M40  0,010 – 0,052
Block of cylinders
Diameter of cylinders (standard):
  – M10/B18
 89,00 – 89,01
  – M20/B20  80,00 – 80,01
  – M20/B25
 84,00 – 84,01
  – M40/B16
 84,000 – 84,014
  – M40/B18  84,000 – 84,014
Ovality of cylinders, no more:
  – M20/B20
0,02
  – M20/B25 0,03
  – The others
0,01
Conicity of cylinders, no more:
  – M20/B20 and M20/B25 0,02
  – the others
0,01
Pistons and rings
Diameter of the piston (standard):
  – M10
88,97
  – M20:
     • B20
79,98
     • B25 83,98
  – M40:
     • factory brand 0 83,985
     • factory brand 00 84,065
Gap between the piston and the cylinder:
  – M10  0,02 – 0,05
  – M20 and M40  0,01 – 0,04
Limit:
  – except B25
0,15
  – B25 0,12
Gaps in joints of piston rings:
  – M10  
     • in the top compression  0,30 – 0,70
     • in the lower compression  0,20 – 0,40
     • in oil scraper  0,25 – 0,50
  – M20 (all rings)  0,25 – 0,50
  – M40:
     • in the top compression
 0,02 – 0,20
     • in the lower compression
 0,02 – 0,10
     • in oil scraper:
  – for B16
 0,02 – 0,10

Inhaling moments (N. of m)

Bolts of covers of radical bearings (change at capital repairs):
  – M10 and M20 60
  – M40
     • 1st stage
20
     • 2nd stage
to tighten on 50 °
Bolts / nut of conrod covers:
  – M10
55
  – M20 and M40
     • 1st stage 20
     • 2nd stage to tighten on 70 °
Covers of basic necks of a cam-shaft (M40)
10
Bolt of an asterisk of an intermediate shaft (M20) 60
Oil pipeline bolts:
  – bolt of M6 or M8 (cap union) 10
  – M5 bolt
5