...How many teeth on the original SPICA pulley out of interest?
18 teeth. No crank-fired ignition allowed. Besides, my Marelli is Plexing with great fortitude!
So, I'm looking at that ridiculous cam pulley nut, and that stupid spacer I had to make for it, and thought why not make my own? I can make a longer nut that accommodates the protuberant shaft without using a separate spacer, and also incorporates a remnant of a sleeve that fits inside the pulley as the stock nut did.
I have a nice length of 2024 Al hex bar, which is pretty strong stuff. I used it to make my timing belt tensioner some time and many pages ago. Certainly, I can't torque down an Al nut as hard as a steel one, but this pulley is lighter, and working less (smaller diameter, no SPICA drive) than the stock unit which is more than 5X heavier. It will be fine when torqued to 90 ft/lbs.
That hex bar is about 45 mm, and I want to retain a 36 mm size. Not only does that size fit with a socket in the smaller pulley, but I don't want to have to buy more large sockets. So I had to shave down the hex by about .100". Drilled, threaded, etc. Installed. Underdriven.
Oh, and I painted that ugly water pump pulley. That's another thing fixed that had been bothering me since the start of this build six or so years ago.