Camshaft drive covers for car models «518», «520», «520i» differ from covers on models «525» And «528».
Valve timing (with an estimated gap of 0.50 mm between the toe of the rocker arm and the back of the cam)
* Tolerance +2.50°.
Total opening angle of intake and exhaust valves: 236°.
The rise of the intake and exhaust camshaft cams, mm:
- «518», «520», «5201»: 7,0267±0,080;
- «525», «528»: 6,8471;
- «528i»: 7,4228;
- «520» from model year 1978, «520i» from model year 1982: 6.850 + 0.08.
The number of teeth of the camshaft sprocket: 26.
The number of teeth of the crankshaft sprocket: 13.
Number of chain links: 94.
From model year 1978, the length of the chain tensioner plunger is 61.8 + 0.2 mm.
Valve timing on models «528» And «528i» (with an estimated gap between the toe of the rocker arm and the back of the cam 0.50 mm)
The beginning of the intake valve before the TDC of the exhaust stroke with the lead: 14°.
Closing of the inlet valve after the BDC of the compression stroke with a delay: 54°.
The beginning of the opening of the exhaust valve to the BDC of the working stroke ahead of: 54°.
Closing of the final valve after TDC of a step of release with delay: 14°.
The total opening angle of the intake and exhaust valves: 248°.
Installation of the gas distribution mechanism
From model year 1978 on BMW «525», «528» And «528i» the following features must be taken into account.
Camshaft markings:
- «525»: label «1, 260°»;
- «528» And «5282»: label «3, 272°».
When removing the camshaft, check the clearance between the mounting flange and the camshaft and replace the mounting flange if necessary.
Valve timing (with an estimated gap between the toe of the rocker arm and the back of the cam 0.30 mm)
BMW «520» from model year 1978 and «520i» from model year 1982
The beginning of the opening of the intake valve to the TDC of the exhaust stroke with the lead: 22°.
Closing of the inlet valve after the BDC of the compression stroke with a delay: 58°.
The beginning of the opening of the exhaust valve to the BDC of the working stroke ahead of: 62°.
Closing of the final valve after TDC of a step of release with delay: 18°.
Camshaft
Camshaft - tricycle («518», «520», «5202») or quadruple («525», «528», «528i», «535i»).
Camshaft specifications
Note. Axial clearance of the camshaft of the BMW engine «520» from model year 1978 and «520i» since model year 1982 is 0.20 mm.