1969 Dart Street/Strip (Re)Build
On to the hoop. To get it to lay flush to the frame, had to grind a bit as shown.
After bolting the hoop to the corner fitting, this kicked the bottom of the hoop outward. You could suck the hoop down to the frame and cause unnecessary preloading into the upper hoop bolts in the corner fitting if you want, but I couldn't live with that. To make the geometry right, a tapered shim needs to be installed between the hoop and corner fitting.
Tapered shim about .030 tapered to .010 fixed the geometry and the hoop now sits flush with no preload. The passenger side is twice as bad and it has a tapered gap in 2 different directions. No pictures of that yet.
Now it's better
Ready to drill the frame for the hoop bar. **Important note: install BOTH upper bolts in the hoop BEFORE you drill the lower hoop holes through the frame. I only had one bolt in place which allowed the hoop to twist or clock enough to where I almost could not get one of the bolts into place because of the misalignment.
I started the frame with a drill start, pulled the hoop out, then drilled all the way through with a 3/8 bit. I then drilled the OUTER HOLES ONLY to 1/2".
Close call!
1/2" bit
Here's the sleeve that installs through the frame to keep it from crushing. On the rear sleeve, take note that the frame is not as thick as it is where the front sleeve installs. You can easily lose this sleeve inside the frame rail and you'll be cussing and fishing it out of there just like I was!
On to the hoop. To get it to lay flush to the frame, had to grind a bit as shown.
After bolting the hoop to the corner fitting, this kicked the bottom of the hoop outward. You could suck the hoop down to the frame and cause unnecessary preloading into the upper hoop bolts in the corner fitting if you want, but I couldn't live with that. To make the geometry right, a tapered shim needs to be installed between the hoop and corner fitting.
Tapered shim about .030 tapered to .010 fixed the geometry and the hoop now sits flush with no preload. The passenger side is twice as bad and it has a tapered gap in 2 different directions. No pictures of that yet.
Now it's better
Ready to drill the frame for the hoop bar. **Important note: install BOTH upper bolts in the hoop BEFORE you drill the lower hoop holes through the frame. I only had one bolt in place which allowed the hoop to twist or clock enough to where I almost could not get one of the bolts into place because of the misalignment.
I started the frame with a drill start, pulled the hoop out, then drilled all the way through with a 3/8 bit. I then drilled the OUTER HOLES ONLY to 1/2".
Close call!
1/2" bit
Here's the sleeve that installs through the frame to keep it from crushing. On the rear sleeve, take note that the frame is not as thick as it is where the front sleeve installs. You can easily lose this sleeve inside the frame rail and you'll be cussing and fishing it out of there just like I was!
