Muffler spring cowl interference

[PilotBrent]

Will be contacting Van's this week for direction on how to best handle, but was curious if anyone has had to deal with this before.

I have been running the engine, balancing carbs etc? as part of Production Acceptance Procedures and yesterday removed the lower cowl. Noticed that I have had some interference between the lower left front muffler spring and the cowl. The vibration has rubbed through both the heat shield and also into the fiberglass and has opened a small hold into the duct that goes to the radiator. May have occurred before the carbs were balanced and the vibration was much more prevalent at low RPM. Muffler itself is not moving when I try to shake it and I don't see any obvious leaks around pipes (have only minimally run the engine however). When installing the muffler I believed I had placed it in the correction position but maybe its a tad the the left to lead to this interference. Anyone else seen this before..

Regardless, will need to repair/patch.

 

[Bill_H]

A common problem. I read about it when building and modified my cowl during construction.. You make a cut there and do a layup, making an indentation. I think I used a piece of 1.5 inch pvc as a form. There are oics of this in the forum. I wound up with about a half inch clearance. "If i were you" and were going to do that now post-build, I would also consider the mod that moves the oil cooler forward. That one is a bit messier...

 

[Bill_H]

See here
http://www.schmetterlingaviation.com/2012/07/only-on-friday.html
And here
http://www.vansairforce.com/community/showthread.php?t=60752

And http://www.vansairforce.com/community/showthread.php?t=60352

 

[rgmwa]

I also modified the cowl during the build as it looked like there was insufficient clearance to the spring.

 

[PilotBrent]

Made fix

Thanks for all the replies. After looking through the links I cut out the section and glassed in a patch. All is good.