Small holes on s80 cylinder head

[nathanepstein]

There are small holes on the top of my s80 cylinder head and was wondering if they are oil ports or just pockets. There is one for every valve (24). Should I worry about cleaning them out or are they unimportant?

[SuperHerman]

I don't recall as working on this head is several years ago. Looking at the photo I would assume they are oil passages. Look for a clean one, take some carb or similar cleaner and insert the plastic pipe into it and spray. See where it comes out and what comes out. What does the other side of the valve cover look out - these may be oil passages to lube the upper cams. Do the same on the corresponding side of the valve cover - if they are oil passages you need those clean. You can spray and use a small wire, copper, and clean them out. If you have a carb wire set, use that. While spraying, be careful of back spray and your eyes.

They could be some exhaust emission passages - just don't remember. They still need to be cleaned out either way.

Head looks good though.

[jimmy57]

They are drilled to intersect he lifter bores. For either hydraulic or the solid buckets. If you look at top of head you will see the "ditch" cast into head to carry oil along the full length of head on intake and exhaust sides.

[thebull]

Oil passages delivering oil to the tappets. Check your cover and you will see how they are matching with the oil canals there. Make sure that you spray compressed air in each hole to ensure there is no obstruction to the oil flow. The are very important holes.

Your pic is bringing some memories back cheers