Head bolts-oily sludge?

[Pablo M]

So if you’ve been following my recent saga I’ve been removing my head sue to a bad valve. 
When removing the head bolts most of them came out ok, but all had a heavy oily sludge at their base. Some were difficult to remove due to this sludge. A couple I couldn’t get out of the head, feeling a combo of bent and/or sludge. Head is free, all bolts came out of the head though. 
 

The sludge, what problems am I looking at here? 

[tech71]

Probably no problems😉 its pretty common in my experience.

Oil makes its way down around the bolt and over the years congeals/thickens.

The problems occur if its not completely cleaned out of the bolt holes in block when reinstalling cylinder head.

With your head off be careful not to set the head down on its sealing surface, the camshaft is holding 1 or more valves open and they stick out below that sealing surface.

Setting it down onto it can bend a valve or two.

Support it somehow. The big boys usually have a stand to place the head in, I use big old bolts reversed and held in place with duct tape

Edited September 11, 2023 by tech71