RV-6A exhaust dents question

[neonbjb]

I'm the owner of a second-hand RV-6A and I recent removed the engine for overhaul. I found that the clearance between the rear exhaust pipes was very tight and, upon removing the pipes, found that one of them has some pretty large dents in it where it rests against the mount.

Looking at the dents, it actually looks like the builder might have created them himself to ensure clearance, but I can't be sure. The motor mounts look fine in the area - they were wrapped with something and just have some paint discoloration.

My question is - is it considered OK to run an exhaust like this? (e.g. one dented, the others clean) Assuming the motor mount is protected, is there anything else I should be worried with? Should I be looking into getting a new exhaust?

 

[PerfTech]

I'm the owner of a second-hand RV-6A and I recent removed the engine for overhaul. I found that the clearance between the rear exhaust pipes was very tight and, upon removing the pipes, found that one of them has some pretty large dents in it where it rests against the mount.

Looking at the dents, it actually looks like the builder might have created them himself to ensure clearance, but I can't be sure. The motor mounts look fine in the area - they were wrapped with something and just have some paint discoloration.

My question is - is it considered OK to run an exhaust like this? (e.g. one dented, the others clean) Assuming the motor mount is protected, is there anything else I should be worried with? Should I be looking into getting a new exhaust?

.... This will most likely have a detrimental effect on performance for that particular cylinder. It may show up in EGT readings, but you should address this and correct it. Allan

 

[neonbjb]

It gets a bit tricky because the engine I have is the IO-320 that uses the Dynafocal-2 engine mount. I suspect the reason that the builder did this "modification" was because of clearance problems related to this type of engine mounts. That being said, I'm not really sure how I would find an exhaust that fits properly and wouldn't need the dents...

 

[az_gila]

It gets a bit tricky because the engine I have is the IO-320 that uses the Dynafocal-2 engine mount. I suspect the reason that the builder did this "modification" was because of clearance problems related to this type of engine mounts. That being said, I'm not really sure how I would find an exhaust that fits properly and wouldn't need the dents...

Is the rest of the Dynafocal II mount different?

I thought the bolt locations were identical, but just at a different angle, and the only thing changed is the welded ring with the cups.

Is this not the case?

Are you confusing it with the O-320 H mount?

 

[neonbjb]

You probably know better than I do. From the reading I've done, it sounded like the engine was located differently relative to the mount for dynafocal-2's - which would presumably necessitate a slightly different mount structure? I don't really know though and I don't have a dynafocal 1 on hand to compare to..

 

[BillL]

Can the pipe be moved, relocated, translated 1 inch and not hit something else? The core of the question is, define how it needs to be modified and get a welding shop to make the change. These things happen.

 

[posterman]

RV6A exhaust hangers part of the issue?

Jim,

You might also look at the exhaust hangers...as I recall the original hanger kits from Van's in the late 90's and early 2000's were widely thought to be not sufficiently stout allowing for too much movement with many reports of broken parts and at least in my circles in far Northern California everyone went with 4130 3/16th's wall or better tubing and then later converted to the kit that bolts onto the rear of the engine block. No reports of issues since that conversion.

Perhaps something to take a look at.