I decided to mount the engine sensors manifold in the position suggested and shown on Van's drawings. The engine wires will pass through a penetration next to the manifold. The penetration uses the SafeAir1 stainless steel kit which is very robust.
I proceeded to drill the penetration using their template and then deburred the FW holes with a rat tail file. I will mount the kit after I insulate the FW with the ceramic insulation which will be covered with stainless steel foil.
