After Camshaft Replacement - Shall I Re-torque TThe Head?

[Pawel66]

I have replaced camshaft (with fitting camshaft bearings in pedestals and shimming the pedestals, as advised), rockers, timing chain, sprocket, etc.

It is all nice and quiet, but it is time to lift the cover and adjust valve clearances, I think (500-700km).

Shall I also re-torque the head?

[Benz Dr.]

I can't see how that would be a bad idea.

[Pawel66]

Ok, thank you, will do then.

I did not remove the head, just followed the procedure from the forum on how to replace the camshaft without removing the head - it was about undoing the bolts one by one, so I was not sure if re-torqueing is necessary. If not necessary - I would not do it.

I have once red a pre-WW2 handbook for car mechanics. In pre-amble it said: "if some assembly or component works - do not mess with it, leave it alone."

[ja17]

Yes, all those new parts installed, and some heat cycles complete, it would do well to re-torque and adjust the valves. Don't forget to release the radiator cap before re-torqueing.

[Pawel66]

Yes, thank you, will folllow.

[WRe]

Hi Pawel,
attached the procedure* from the workshop manual (sorry in German).
...WRe

* Google tranlator and me
After assembling the cylinder head, start the engine with a low load to 80 "C cooling water temperature.
After approx. 5 minutes running time with this cooling water temperature, the cylinder head bolts are torqued to the
specified values with warm engine.

Second tightening after further 300-1000 km of driving.
Caution: When tightening the cylinder head bolts there is a risk that a necessary tightening sequence is because the loosening torque is usually higher than the prescribed tightening torque and thereby in the first tightening phase, the indication may be above the target attractive value. To ensure that the cylinder head gasket is really a pressure according to the prescribed values when tightening the cylinder head bolts, proceed as follows: In the order of the tightening sequence untight each screw a littler bit and tight then only to the prescribed torque. Under no circumstances should all screws be loosened in one go and then tightened.

[Pawel66]

Thank you!
Very helpful!

[mrfatboy]

To add to WRE's answer here are the instructions in English from Metric motors.

I converted to PDF also and attached.

[Pawel66]

Thank you!

Very helpful indeed!