Spent both days this weekend working on the oil cooler mounting bracket, and associated airflow control knob. It doesn't look like a lot of progress but this is all custom built, so a lot of thinking and making parts from scratch, some of which ended up in the scrap bin along the way.
I was going to bolt the oil cooler bracket to the firewall, but I didn't like the idea of drilling large holes in the stiffener angles to accomodate AN3 bolts, so I decided to use rivets instead.
Two of the rivets shown in the second picture have a doubler plate behind, just to spread the load across the firewall better.
I also finished off the airflow control know bracket (bottom picture), and routed the control cable out through the firewall.
Firewall mounted oil cooler
I secured the oil cooler bracket to firewall stiffeners where possible
