Aug 12, 2021     New firewall - (2 hours)       Category: Firewall

Cut out new firewall. Working with SST is slow and hard on tools. Angle grinder works well for the initial cut but to smooth the contours and clean the edges requires some patience with the files. Drilling holes in the SST is hard on drill bits. The procedure is to go slow with a lot of pressure. Mounted the firewall and then match drilled the bolt holes for the engine mount. There are two AN5 bolts for each of the four corners of the engine mount, so eight 5/16" holes. I ruined only one drill bit. I consider that a success. ;-)

Since I won't be using the original engine, I won't drill or cut any more holes in the firewall until the engine is mounted and the locations for passthroughs are obvious.

  Aug 10, 2021     Checked over the firewall - (1 hour)       Category: Firewall

Reviewed the original firewall and identified pass throughs. Picked up some SST from local supplier for new firewall. Original firewall was a sandwich of two layers of thin aluminum with an asbestos-type material in between. Both layers of the original aluminum were damaged and there's hardly anything left of the asbestos-type material, only some pieces and particles where it was glued to the aluminum.
The original sandwich firewall required spacers and blockage to prevent it from being crushed between the frame and engine mount and where anything was bolted to the firewall.
I'll use a single sheet of 0.024" SST instead. It's simpler and safer.