The "Simple" Winter Project Continues

 My thinking about this project was short on thinking and long on dreaming.  I thought "It's basically a lower and an upper bracket."  It is that, but I also thought I would just find a place to drill a 1/2" hole for the bottom coil-over mount and that would be it.  Physics and kinematics had different ideas.

The lower A-arm bracket is managing the geometry changes that will hopefully lead to faster lap times.  As I mentioned in the last post, an MGB has a fixed camber of 0 degrees.  Autocrossing demands closer to 3 degrees.  That is about a 1/2" movement of the inner pivot of the lower A-arm outward.  The movement of the roll center upwards by about 3", means that that pivot point has to move upward about 3/4".  Triangles are crazy.  

The top bracket replaces the venerable lever shock (and I do mean venerable, these were very elegant shock absorbers, from a time when the concept was barely understood, that saved weight by incorporating the upper A-arm into the shock absorber).

I feel bad removing these, especially given their excellent condition.  As I often joke with my British car friends (OK, friend) "What were these losers thinking, designing for a mere 56 years of durability?!"  But, I wanted the benefit of adjustable damping and ride height.  I hope that will pay off.

In any case, the new top brackets hold the upper A-arms, painfully removed as seen below:

I wanted to re-use them since I know they can take the loading and I want to keep at least a few of the original parts intact!  A ball joint puller, with the fork slightly enlarged, proved to be perfect for the job.

Here is the new upper bracket in work:

I'm pretty happy with my welding memory.  I've got many hours of experience but most of it years ago.  However, my technique of tack welding with the Forney wire feeder and then following up with my old Lincoln stick welder, seems to have worked!  One has to be careful to set up the tacks against each other, so they can hold on when the main weld goes in.  

The lower bracket was easier:

The lathe work on the washers and bushing supports was really fun!  What I really overlooked was the lower shock mount.  As I said in the opening, I thought I'd find a way to drill a 1/2" hole somewhere and be done with it.  Haha.  Here's what I ended up designing and fabricating:

Much more work than either previous bracket but it came out well.  Here are all the parts before final fitment:

As usual, I underestimated the re-assembly process.  By the time I used the torque wrench on every bolt, and corrected every little misalignment, it was 3 hours per side to reassemble.  But it came out nicely:

You can see (if you zoom in) that the A -arms are 3 degrees downhill as designed.  It's harder to tell from this picture, but there exists 2 degrees of negative camber!  Rarely seen in an MGB!  Here's hoping that's magic at the autocross!

Thanks for reading and keep on having #funwithcars !