I didn't think that a workable solution to the clutch operation would take me as long as it has, but not doing the research and the calcs in the first place and thinking I could wing it with a novel idea, was the start of my tangential wanderings.
The Land Rover Series II master and slave cylinders arrived, and it was immediately obvious was that a deep spacer between the slave and the bracket was needed.
Cheap hole saws are not ideal for this kind of work though luckily, I had an undersized one that would get me close enough before finishing with the boring head. (Note to self: cheap boring tools are equally eccentric in their behaviour).
So far so good. All the time I was making the hole for the slave cylinder, I was trying to work out the best way to secure the bracket in the mill to create the hole for the clutch lever shaft bush.
I made the bush a gnat's oversize, shrunk it into its housing and then cleaned up the internal bore to fit. The hole in the bracket was a bit of a fiasco - the tooling picked up a couple of times and I lost the centre. I got around it in the end and the ½mm gap all round was acceptable for tacking.
Everything was going very well, and I was thinking about congratulating myself (always a risky business) when Mr Holmes reminded me that I hadn't yet addressed the return spring. This turned out to be the most difficult part of the whole operation and, need I tell you; I went off at a tangent with a neat but fundamentally useless idea that doesn't warrant column inches. And so the end of the umpteenth day.
I was casting about for a robust spring when I remembered that the Riley brake and clutch pedal return spring was a possible candidate. Cut in half, the bracket slotted to anchor one end and suddenly all my clutch woes were as nought. Yahoo! I popped the bush in the lathe and stepped one side to the i.d. of the spring so getting it to sit parallel to the shaft.
Though I haven't yet connected the hydraulics and exactly adjusted the throw of the piston's rod, I'm pretty confident that this is going to work, and I like the compact and tidy nature of the conversion.
Though slightly awkward to assemble - I've made this special tool to pull back the return spring hook and slip it over the clutch lever - it's not an everyday maintenance job and provided I remember to face the slave cylinder's bleed nipple to the outside, all should be well.
With the gearbox back in place, and the bracket being 6mm thick, I've sorted out three bolts of extra length to accommodate.
I think this might be a Triumph Herald handbrake. It's now a bit longer and all I have to do is work out how and where to mount it for another problem solved.