Well, this is the sweet picture of success!
That is one chain tensioner bolt fully inserted, torqued and secured!
My anxiety about doing this job was quickly dismissed as the tap went straight in (secured by the guide) and took very little force to twist through. We were able to use a standard length 16mm spanner to easily turn the tap into the thread as it was held by the guide.
The tap was packed full of grease to collect any shavings and that was a good idea (for lube also) even though very little aluminium came out. We also stuffed a small bit of cloth into the back of the hole to ensure nothing was pushed out the end into the chain casing.
Once the tap was complete (seriously in less than 5 minutes after all this waiting!) I attempted to wind the bolt back in by hand but it bound! Gulp! All that was required here though was to clean up the bolt threads with some steel wool and PRESTO it wound right in...
With the correct tools on hand the job took 20 mins max.
Based on this experience it's obvious that the threads had minor fouling rather than any serious stripping or crossing. The thread is M26x1.5 so it's very fine for the size and obviously very intolerant of any deformation. Smoothing them back out was ultimately a simple exercise (but one that had me very, very worried).
I'm not really sure what the moral of this story is but here are a few things that occurred along the way:
1. I met some really awesome people from here at Bimmersport and got some really helpful advice. Two people in particular were amazing with their time, support, knowledge and tools - thank you Ian and Mark, you're legends!
2. I had a great time with Mike at Brendon Engineering where he was always happy to invite me into the machine room and play with the (manual) tools. Wow they've got some cool equipment there! For the $80 I spent on a piece-of-mind tool I got many hours of engineering and equipment education, that was invaluable.
3. Sometimes you encounter problems that there's little or no information on and when you're inexperienced this can be intimidating. When you reach out for knowledge, take your time and equip yourself with the correct tools you can find that seemingly insurmountable obstacles are less challenging than you anticipated.
Now I've just got to receive my parts from the US and put the bloody VANOS back together! Not counting my chickens until that's all done so wish me luck!
Thanks for caring.