Some more progress today.
I've got the head fully rebuilt and cleaned as best as I can. A nice grey seal around each valve, all nice and tight, new stem seals all fitted, a check that all collets are in properly:
The engine block, in the final stages of being cleaned:

The head gasket, fitted:

Inlet manifold gasket located, ready fit manifold:

And, the head fitted onto the block, with inlet manifold attached

I then fitted the lifters (which interestingly aren't hydraulic like Omegas) and fitted the "thingy" (I dunno what it's called) that the camshafts run in. There's another gasket on the face of the head you see here, and it bolts on.
Anyway then I started looking at the timing.
Because it's a variable valve setup, the outer ring on the teeth on the exhaust cam needs to be tensioned, and a special tool fitted to hold it in place.
The special tool from VX is called to tension this gear is called "EN-6092-10 fixing tool" and I could not find the bloody thing anywhere online for love nor money. It's no4 in this image:

So, sod it, I'll make my own.
Ingredients:
1) A broken / old / unwanted glow plug. In this case, the one that melted in no4 chamber was perfect.
2) Ideally a vice, but otherwise, a bit of wood, and some mole grips.
3) The trusty old angle grinder, that has so far done me proud on this job

nb - a small hacksaw would be fine too, but why make life hard!
Solution:
1) Cut this bit off the end of the glowplug

Pretension your ring gear, and shove said bit of glowplug in this hole.
https://www.mycarphotos.co.uk/images/photos/988/99/f691adf6a650ab344e472f17.jpgFit the camshafts to the car, making sure the marks are lined up as per the red circle below, and also that the timing bolt fits correctly in the camshaft (belt end) sprocket

Which in reality, along with my makeshift tool, looks like:

That's all for today, and probably the next few, looking at the weather.
It's noteworthy that unlike the omega head bolts, which are 25nm, followed by 2 x 90deg turns, (and a 15deg tolerence turn if you wish) - this head is 50nm, x 90 x 90.
I could not believe the forces required to achieve it, but the bolts didn't feel they would break (I thought the extension bar would go first!). I guess it's because it's a diseasel.
Beer time
