Having previously cut a hatch access in the bottom of the fuselage, a bit more surgery was required to allow easier access to the area behind the firewall. I cut the webs from the lite ply horizontal brace.
This, along with widening the hatch to the width of the cowl opening allowed plenty of room for access.
I also installed firewall penetrations for the fuel line & muffler pressure in at this time. I cut 1 1/2" long sections of 1/8" brass tubing & inserted them 5/8" into the medium fuel line & secured them W/double cable ties. 1/8" holes were drilled in the appropriate locations in the firewall & an Allen socket driver was used to fish the tube into the holes from behind. I secured the tube penetrations W/CA.
Having that out of the way, I finalized the location of the ignition module to put the least amount of stress on the spark lead as possible. I applied three pieces of hook section Velcro to the inside of the fuselage on the port side. I covered a generous section, much larger than actually needed to assure that I would not pull edges up when removing the module. The module was wrapped in such a way that the loop sections extended around the edges for similar reasons. Once the module is pressed into the hook sections of Velcro, it makes for a secure yet vibration isolating mount. That is a C&H Electronics Mk-I Syncro-Spark module made in 1997. It had only been used for bench testing. This will be its 1st ride in an airframe.
I used some 1/4" X 3/8" basswood to frame the opening to restore some of the structural rigidity that was compromised by cutting the hatch opening & web removal.
I am employing 1/8" birch ply for the hatch & when it is anchored W/2 screws in the bottom of the firewall & 2 more in the rear cross member that was added, structural rigidity should be as good or better than original. Note the rubber grommet at the spark lead penetration.
Stay tuned for the Installation & plumbing of the 32oz Sullivan tank W/overflow lines for both 16oz & 32oz fill.