This model is based on 8-valve cylinder head found from Volvo's 2.0 - 2.3l "Redblock" engines (B200-B230). It uses singular overhead camshaft operating the valves without rockers. Volvo has made these with various configurations, different camshafts etc as it's standard head found in both turbocharged and non-turbo redblocks. These heads don't have bearings for camshaft either, it's simply locked in place with the collars and constantly lubricated with oil channels running around the cam mounts. Super simple.
This isn't meant to be an exact replica: some measurements are off, intake/exhaust channels are very basic (straight to the valves) and coolant channels are completely missing.
However all the mechanical stuff works and it provides good view of OHC head operation. This isn't an easy build, and requires lots of patience in assembly. Some tolerances are quite tight and sanding/drilling might be necessary to fit components together smoothly. Also the head printing time is quite long (>12h) so make sure your printer is properly calibrated and able to accomplish such a long print!
Camshaft can be printed in one piece if the height of the build platform is sufficient. If not, print it in 2 cuts and glue the parts together. There is a small alignment mark in the split camshaft files to allow proper alignment of the both parts, and you can insert 4mm stud inside the hollow to further help with the alignment. Parts that need supports: Head.stl Camshaft_T.stl (and its cuts) Rest can be printed without support given that your printer can handle some long-ish bridges.