Cylinder Head Oil gallery plugs

[DogsbolloxofZ1B]

Does anyone know the dimensions of the oil gallery plugs in the cylinder head on a Z1? I need to get a few made.
What's the best method of removing them?

Cheers,...

[zed1015]

Carefully drill up the centre, tap them M5 and draw them out using a 5mm bolt and a spacer or two.
Just screw in the bolt with a spacer tube between the head and bolt ( M8 nut will do the trick) and keep tightening and they will pull out.
They are only a light press fit, about 10mm long and come out easily.
I usually only remove them when i'm converting to external cam feeds so haven't actually measured them accurately for press in replacements but on my last project I tapped them M8 to take stainless cap head blanking screws so they must be about 6mm.

[DogsbolloxofZ1B]

Perfect, just the info I needed.

Cheers, Mike

[Garn 1]

Dogs', just for further info, these oil plugs on the early Z1's have steel plugs later models have alloy.
Out of interest, why are they being removed eg for cleaning, for adapting oil inlet/ outlet, to cover up previous screw holes or were they leaking.
RegardZ.

[DogsbolloxofZ1B]

Dogs', just for further info, these oil plugs on the early Z1's have steel plugs later models have alloy.
Out of interest, why are they being removed eg for cleaning, for adapting oil inlet/ outlet, to cover up previous screw holes or were they leaking.
RegardZ.

Garn1,
Two are leaking and the engine is about to goto Steve Smethurst for the full vapour & bull mill rolling process so I want to ensure no grit gets left in the oil galleries or anything else for that matter Yes thanks for the reminder on the Steel Vs Ally.

Cheers, Mike