What was happening throughout 20 years of flying was that engine oil, spilled at every oil change near the top of the firewall, dripped to the top of the NACA diffuser (part of the NACA duct entering the engine compartment) and collected there. Because of the many systems attached to the firewall, cleanup was impossible (I tried many times), and the spilled oil slowly wicked its way up the porous ceramic mat by capillary action.
The big question in my mind at this point was… Is this FiberFrax still able to reject heat, or will it go up in flame in contact with the structural fiberglass of the spar?
Only one way to find out…
