Hangar Flying => Hangar Flying => Topic started by: flyboy on October 02, 2009, 10:28:24 AM
Title: Header Wrap
Post by: flyboy on October 02, 2009, 10:28:24 AM
I don't see too many EZ's with header wrap. Its designed to lower the temp of the header, which I would think would help with CHT cooling. Anyone know why we don't see more EZ's using it? Other than weight of course :)
Title: Re: Header Wrap
Post by: flyingwaldo on October 02, 2009, 01:17:01 PM
Hides cracks.......?
Title: Re: Header Wrap
Post by: A. Bruce Hughes on November 02, 2009, 09:03:59 PM
What do you mean by "header"?
If that means the exhaust pipes, it is a VERY BAD idea.
Ask me how I know.
Bruce Hughes
Title: Re: Header Wrap
Post by: Juan Rivera on November 03, 2009, 11:55:56 AM
How do you know?
Title: Re: Header Wrap
Post by: A. Bruce Hughes on November 03, 2009, 11:43:03 PM
If "header" refers to the exhaust system, I can tell you of my experience.
OK - what is the "header"?
Bruce Hughes
Title: Re: Header Wrap
Post by: Hmanvel on November 07, 2009, 04:58:10 AM
Some people use the header wrap and have good results, others do not. I have my front engine headers wrapped but will remove the wrap at annual to inspect the pipes. I have been told that because they hold in heat, they can cause cracking in the pipes.
Bruce, Tell us your story? Did you have problems with the wrapping? BTW "headers" refers to the exhaust piping.
Title: Re: Header Wrap
Post by: A. Bruce Hughes on November 07, 2009, 10:09:41 AM
Hi guys
When I had my Lycoming 235 engine on the Longeze, I heard about wrapping material for the exhaust pipes. The manufacturer said it would cure everything except athlete's foot. I wrapped mine. At the time I was doing some "taxi testing". Those were short - maybe 10 minutes each.
Cylinders #1 and #3 go to one manifold, #2 and #4 to the other.
After 5 or 6 times, I noticed something; the nuts (holding the exhaust manifolds on) were looking odd. I tried to remove them and got 6 off. The other 2 were frozen in place with excessive oxidation and flaking off the surface. Those nuts were the ones sold by Aircraft Spruce and Specialty for exhaust studs. I interpret the result as that the wrapping caused the studs and nuts to get too hot, causing deterioration of the metal.
I finally got the last 2 nuts off by filling the deteriorated surface on 2 sides of the nut down to fit a 5/16" wrench, then turning 120 degrees. Then filing one 2 sides, turning another 120 degrees. Then filing the last 2 sides and turning again. Eventually I got a 5/16" socket wrench on them.
My "headers" are not wrapped now.
Did I mention that I have been working on this airplane for 15 years? >:(