Hello Bart,
OK – seems we have a real problem.
What could have caused that:
- hydrolock cause by AOS failure
- failing IMSB
- bad chain tensioner
- bad chain rail
What to do next:
You can move the chain while lowering the engine and removing the the head cover. But there is not much room. Also you have to find the cause why the chain skipped over one teeth. And you have to check if anything else is damaged – valves, valve seats, hydraulic lifters…
So you have to pull the engine, fix camshafts, crankshaft, remove the cylinder read of bank 1, check chain tensioners, valves, hydraulic lifters, chain tensioners, IMSB…
To to this you'll need special tools and / or the skills and tools to build them. I also would recommend a lift.
Also you have to think about how to pull the engine. Fastest way is to pull the complete drivetrain including engine, transmission, axles, struts, exhaust system in one piece. But that is not possible in a workshop without lift, good tools…
Slowest way is to remove everything piece by piece. That is doable in a home garage, but takes time.
I don't know you skills and tools. Also i don't know if you have the time, space, skills, tools… to do that. It's not rocket science but it will take time and money.
If you want to do it yourself i would recommend to buy a good workshop manual and read what things are have to be done. There are also videos on youtube, but these don't show everything. There are people on this forum that might help you when you stuck.
If you read everything, know what tools you need, know what has to be done, know what additional work has to be done (for example bleeding the cooling system), know what maintenance work can be done if the engine is out of the car, know what tools you will need – than you should start. Not before.
Else bring it to am experienced Porsche shop. But it will cost some money. I would recommend to ask for a cost estimate to diagnose. Will be hard to get a cost estimate for the final repair, as we don't know what failed and what is damaged.
Maybe some guys in your region can help you. I saw you might attend a meeting. Maybe good idea to talk to other Porsche owners in person and discuss what to do.
Don't turn on the engine.
Regards from Germany
Markus