Hi Paul-

I was inspecting the lower cowl area after getting the engine running again
post-electrical changes.  I noticed that the fiberglass is showing signs of
heat damage from the heat coming off the VAM muffler.

When Mark Steitle was here with his 20b, I saw that he had fashioned a heat
shield to cover the exhaust manifold, as well as applied reflective
barriers
on the fiberglass.

I ordered some of the reflective barrier for the motor mount tubes &
fiberglass yesterday.  Getting a similar heat shield around the VAM will be
tricky.  And I wonder whether there is some minimum air gap I would have to
respect, lest the VAM melt itself.

Your thoughts??

Mark (Rocky Mtn High)

I don't know what that airgap would be. Depends on the effectiveness
of the insulation. Fiberfrax has a good reputation covered with
26 gage SS. (very thin)

Makes sure you get a blast air cooling tube to the center pipe in the
muffler.

Steve Beckham is putting a metal bubble on his cowl near the exhaust.

Paul Lamar



I assume insulating the exterior of the VAM itself is a no-no.  I seem to
remember an email from the past where it came up and the thought was that
allowing the exhaust to cool itself (vs being wrapped in some sort of
insulation) was necessary to prevent the failure of the system.

Mark

Yes I agree you need to get some cooling air around the outside.

Paul Lamar