cylinder head oil gallery plugs

[jake]

am looking to remove the 4 plugs each end of the cylinder head,was going to drill/tap them and pull with a slide hammer BUT thought i'd better check that plugs are push fit and not threaded,head is z900 and after paint stripping/blasting wanted to make sure no muck is left behind , anyone been there done that????

[zed1015]

You should be able to get the head flushed without resorting to that but they are easy to get out as they are light press fit.

[Garn 1]

Interesting question. Even if these plugs are a light press fit, how do we get them out? The only way I can see is to drill and tap them and then, some how, extract them wth some make-shift puller. You can't get behind them, to drift them out. Is there an easy way?
RegardZ.

[zed1015]

I usually remove mine so i can drill and tap m10 for external cam oiling set ups. I use a 5 or 6mm flat punch to carefully tap the plugs in about 1mm so the diameter can easily be seen for accurate center punching. Then the bungs are drilled and tapped M5 ( Best to pilot with a much smaller drill and work up ) . I then use a long m5 bolt , nut and large penny washer (in that order) which is passed through a sleeve bored 8mm and screwed into the bung. Whilst holding the bolt still, i tighten the nut against the washer which draws the bung out and eventually clear in to the sleeve. Bungs are only around 15mm long and come out with little effort.

[Garn 1]

Zed1015, thanks for that removal description. Well done. I take it you make new ones to press back in! I have seen some with an allan-headed grub screw in them, perhaps these are just the originals pressed back.
RegardZ.

[zed1015]

I only remove them to fit the external cam oil feeds. No need to take them out to flush them after blast cleaning. Must have done 100 heads over the years with no probs. Removing the plugs just to check the oil passage way is clear is a bit extreme but if you must then tap and plug with a grub screw unless you have access to a lathe.