My experience with fiberfax was not ideal. I lined the bottom of my cowling
with it to protect the fiberglass from the heat of the exhaust -
unfortunately, it absorbs oil like a wick and I was concerned about just
that. Perhaps,if you cover the fiberfax with something like SS or anything
to keep the oil away, then it may be OK. I also found it fairly fragile
and easy to tear. Just my experience with it - YMMV
Ed
Ed;
Fiberfrax is intended as a thermal insulation used between other surfaces, such as on the firewall behind a thin SS barrier. For your cowl protection you might want to consider an aluminized reflective barrier such as:
which will not absorb oil. I got it at a local speed shop.
Al