[PeteP]

Final fitting my lower cowl today and discovered that the right exhaust stack only has about 1/2 " clearance between both the engine mount and the cowl no matter how I rotate it. The left stack has about an inch clearance. It is the standard Vetterman exhaust and a 9A mount and the cowl has a good fit to the fuselage. Have other encounter this and is there a method that I have not discovered?

 

[crabandy]

My RV7 (O-360) vetterman crossover exhaust is closer to the right side of the cowl near the outlet bump because of the heat muff. I spent quite a bit of time twisting the exhaust to maximize clearance but I didn't gain a lot. After about 10 hours the cowling discolored the most underneath the # 2 cylinder where the two exhaust come together not where the pipes were closest to the cowl. I suppose there is not as much air moving in the forward part of the cowling causing the heat buildup. I added the heat shield foil from vans.
Pic of discoloration under #2 cylinder even though the exhaust is much closer to the right side of the outlet of the cowl.

Heat shield in place.

 

[LarryT]

Consider the Van's heat shield

Where the clearance was closest on my -6A I added one of the small Van's heat shield, which i had modified by riveting a piece of high temp silicone (red) to the outside surface of the shield. The silicone pad serves two purpose: it is relatively non-conducting; it provides a "friendly surface if the engine moves enough during start-up/shutdown to contact the cowl.

The paint previously blistered in this area. Since I made the change, I have 100+ hours without any paint discoloration. I think I posted about this 2 - 3 years ago.

Larry Tompkins
544WB -6A
W52 Battle Ground, WA