Piston rings close to design life span or not

[aquazulu2]

Hello folks, I continue to assess a top end rebuild/fix on a 1986 911 Targa. An unscheduled rebuild due to broken head bolts found during a valve adjustment.
Currently assessing the piston rings for keep or replace. The gap for the compression rings (top two) shows 0.50MM/.020" the wear limit suggests 0.80mm.
Question: Would you keep or replace with new. Can I realistically expect to get new installs with a 0.2mm gap.

With 0.3mm remaining to wear limit, would you leave them in.. (MAHLE Pistons)..

Thanks for any help..

I believe I dropped this in the technical forum in error, I wonder if a moderator can flip it over to the rebuilding forum for me..

[kodioneill]

Replace them for sure, they get brittle.

[GH85Carrera]

I would have to agree, replace them.

[wwest]

I don't know how or why head bolt failure led to this question but once the piston rings are outside the cylinder jug I would NOT attempt to re-use, compress and re-insert.

[aquazulu2]

Originally Posted by wwest

I don't know how or why head bolt failure led to this question but once the piston rings are outside the cylinder jug I would NOT attempt to re-use, compress and re-insert.

Thanks for the confirm. I expect I should have said that because of the broken head bolts I have to go in further than my budget will comfortably allow, to the point I have to decide on go or no go rings. I only planned a valve adjustment. So now instead of valve cover kit, I need a engine rebuild kit, heads to machine shop to remove broken exhaust studs, need to purchase set of head bolts, and the special tools to go in where the broken head studs take me. I may have to extend the project to make sure I do what is logical before putting it back together. A broken head stud may take you where you had no plans to go.

Sorry for the dump, New piston rings in the basket..