It's taken nearly a decade to quit working on other people's projects and begin tackling my grandfather's 1971 Fiat 850. He was quite the hot-rodder back in the day, having replaced the original 903cc engine with a Fiat 124-based twin-cam 1608cc engine, and adapting a Porsche 901 5-speed transaxle with the help of a PBS bellhousing adapter. This was a quick little car, and should be lighter and quicker when it eventually returns to the road and track.
This is where the car stood over 10 years ago, sans engine (which was disassembled, awaiting its rebuild when my grandfather passed).
Given the age, size, and lightweight composition of the 850, it's going to see minimal time back on the street. I fear even a modest collision with a modern vehicle would be catastrophic (a collision with a pickup truck or SUV might be fatal). Heck, even hitting any of SC's ubiquitous potholes would likely rip one of its tiny wheels clean off the car. So, I'm focusing a fair amount of fabrication towards making the car track-worthy. Here, I fabricate a set of brake caliper brackets to mount Wilwood GP 320 brakes at the front wheels.
I think I have a 4-jaw chuck for my lathe, I just don't know where it is. If you've seen my garage, you'd understand that this was arguably easier and quicker than finding it. If you've seen my grandfather's garage, you might understand my garage.
Starting with a 6"x5"x0.75" plate of 6061-T6 aluminum (wait, wait, wait..."aircraft grade aluminum"), I milled a notch on one edge...
...to locate the plate on one of the three jaws of the lathe chuck, effectively offsetting the center of the aluminum.
Then bored a hole for the plate to fit around the spindle.
I previously used the DRO on my mill to measure the bolt-hole locations of the original caliper mount/backing plate. With those measurements, relative to the centerline for the spindle, I was able to precisely drill the holes for mount and caliper.
The plate returns to the lathe to begin removing material and offset the caliper-mounting face from the spindle-mounting face.
Flip the plate over and continue to remove material.
And bevel it, as if I know what I'm doing here.
Hot off the lathe, outside...
...and inside.
Then roughed out in the mill.
And mocked up. I suppose if I knew what I were doing, I'd have accounted for the caster angle and rotated the positions of the caliper mounting holes so that the caliper was located precisely at 90-degrees to the horizontal.
Caliper brackets, after some time on the rotary table, milling a radius around each corner; and, installing steel inserts where the caliper mounts.
Inside face of the caliper brackets.
Glamor shots.
Bracket mounted to the spindle. 12-pt metric hardware, 'cuz I care just that much.
Swanky.
I massaged the front hub a bit on the lathe. I've seen where others have removed significantly more material on the 850 hubs (i.e. such as the late John Edwards)...I'm not yet sure if I'll take these to that extreme, or instead reproduce the entire hub in aluminum. I need to tackle other mods first.
Here's the assembled front brake, with vented/drilled/slotted rotor and Wilwood caliper.
More 12-pt and ARP hardware. Because race car.
