Reapriete of butt bolts (Head Cylinder)

I have a question about cylinder head bolt retorquing. Some people tell me it should be done every 600 to 1000 km. Is this retorquing standard practice, or was it only done in the past? And what happens when the torque specifications are given in degrees? Do they need to be retorqued, or do they only retain the torque specified at the last setting?

That's just a myth...it used to be talked about, but because of the alloys, it's only done once. If you retighten them, you can warp the head or damage the bolt or head gasket. Some bolts are single-use and must be replaced when doing a major engine repair. Tightening in degrees also works and is very useful and not very difficult. Cheers.

Greetings.
Retorque adjustments are only used on some vehicles, and this is specified in the manufacturer's manuals. There are many available online; some, like Ajusa and Moresa, indicate the torque, vehicle order, year, engine, etc. Always refer to the manual. For example, the 1986 Isuzu pickup truck with a 4ZD1 four-cylinder, 2.2-liter engine has 10 bolts on the cylinder head, and the manual states that they should be retorqued at 1000 km by loosening them 90° and then tightening them again to 72 ft-lbs. Again, before tightening, consult the manual.

That's what I wanted to read; I imagined something like that.
Conclusion: it all depends on which engine you're working on, and its respective manual.

Thanks LT-zeta and ravesa1011661