Engine Mount Sagging

[Ken Holcomb]

After 600 hours, my exhaust pipes are touching the lower cowling. Is there a way to reposition the engine to rise it slightly? Rotate the engine mounts?

RV-7, angle valve 200 HP

[PCHunt]

Ken, I don't think that the engine mounts would sag enough to cause your issue. If the engine mounts sagged that much, your prop spinner would be badly misaligned with the cowl, and might even be hitting the cowl.

More likely is that the exhaust pipe hangar straps have "sagged".

Why don't I drop by and we can have a closer look?

Pete

Sent PM>

[Ken Holcomb]

Hi Pete,

Thanks for the reply. I'll stop by.

Ken

[Selmax]

How can I fix this one:

The exhaust pipe hangar straps have sagged (RV9a / O320). My ones are made of short pieces of tube and aluminum pipes stucked into each other and fastened with metal clamps. I am not the builder, thats why I am asking

Thanks Pit

[Selmax]

How can I fix this one:

The exhaust pipe hangar straps have sagged (RV9a / O320). My ones are made of short pieces of tube and aluminum pipes stucked into each other and fastened with metal clamps. I am not the builder, thats why I am asking

Thanks Pit

[Pat Hatch]

Pit,

All you need to do is loosen the metal clamps on the hose, slide the aluminum tubes further into the hose and re-tighten the metal clamps. Make sure you clean out the hose and tubes especially to remove any lubricants. I also did one other thing: I flared the aluminum tube ends slightly so that they would be gripped by the hose/clamps more firmly. Hope this helps.

[Walt]

I usually just replace the rubber hose if they need adjustment, fighting with old hose which is hard and has lost its resilience isn't worth the effort.

[BillC]

Pit,

I had the same issue and did what Pat suggested and put a slight flair on the tube ends so the hose clamps would not slide past. This fixed the problem for me and have not had an issue for the past 3+ years.

YMMV
Bill

[Selmax]

Bill, Walt and Pat,

many thanks. I took a new piece of pipe and rubber hose, but didn't work really good. I guess I should use new and larger clamps too or better drilling small holes through hose and pipe to get a bolt thru and a nut with rounded washers to meet the rounding of the tube. What kind of clamps would you use?

Thanks Pit

[Pat Hatch]

Pit,

I would use the standard hose clamps:

http://www.aircraftspruce.com/catalo...breezemini.php

as seen here from Aircraft Spruce. Not sure drilling a hole through the hose and tube is such a good idea, but maybe I'm not understanding what you want to do. If you flare the aluminum tube on the end a little bit, this will be enough to keep the tubes from sliding around inside the hose. You want the hose to flex a little to absorb vibration. Good luck!