Sealing exhaust

acam37 · #1 11-28-2015, 08:42 AM

I need to know what is the best way to seal an exhaust pipe slip joint connection? I have a standard exhaust system for the 0-320 that has slip joint connections where they cross over under the engine. The problem is that unburnt smoke oil is is blowing out of the joint and covering the engine causing a big mess and potential fire hazard. I thought of just welding it up, but not sure if the slip joint is there for a reason, such as allowing flex in the exhaust system.

Michael Burbidge · #2 11-28-2015, 08:50 AM

Something doesn't sound right to me. Do you have them tightened per instructions?

My slip joints are tight and would not allow either exhaust or oil to pass through. I suppose if you have a lot of vibration the small springs might allow momentary leakage of the joint.

The joints are there to provide flex between the engine and the mounts. I don't think you want to weld them. In fact you are supposed to lube them with something similar to Mouse Milk to keep them flexible.

Michael-

acam37 · #3 11-28-2015, 09:13 AM

The slip joints are not connected by springs or any other method. One pipe just slides into the other. That's how it was when I bought the plane. I have no idea who made the exhaust system. I'll try to post a picture later. If I can't figure out how to make a good seal then my smoke system is useless.

FORANE · #4 11-28-2015, 09:16 AM

How about exhaust wrap?

rvbuilder2002 · #5 11-28-2015, 01:32 PM

They are called slip joints for a reason. The pipes need to be able to move with heat expansion/contraction so the joints should be very slightly loose ( a sure way to destroy the system is to attempt to seal them by clamping).

Exhaust wrap is also a bad idea (search the forums)

It sounds to me like you are injecting too much oil. Do you have a means of flow control on your system?

Johnnybgoode · #6 11-28-2015, 02:17 PM

I'm on the road so can't include photos but mine have springs that hold the sections together. They are attached to tabs welded on each pipe. Doing so should seal the pipes on the inside of the joint, at least moreso than just a pressed fit. I'll try to get you a picture when I get home - would be an easy addition. Agree that welding isn't the answer.
Patrick

acam37 · #7 11-28-2015, 03:24 PM

We have the smoke System Helper complete kit. I turned the injection regulator as far down as it would go and still make good smoke. I don't think this exhaust system is compatible for smoke. Seems like my only alternative is to put the injectors on the other side of the joint, which won't give the smoke oil enough time in the pipes to create smoke. I also thought about using a flex joint, like this http://www.ebay.com/itm/1-3-4-x-6-Do...hWTJBt&vxp=mtr

rvbuilder2002 · #8 11-28-2015, 03:36 PM

Most people with smoke systems are also using the common crossover exhaust systems without much trouble.

cajunwings · #9 11-28-2015, 04:40 PM

Any chance the slip joint is just not a tight enough fit? Fixed a situation like this before with careful use of a tailpipe expander tool.

Don B.

RV 9. Rebuild in Progress

RV7A Flyer · #10 11-28-2015, 04:43 PM

Quote:

Originally Posted by acam37

Seems like my only alternative is to put the injectors on the other side of the joint, which won't give the smoke oil enough time in the pipes to create smoke.

Mine, and several others I know of, are after all the slip joints and ball joints, maybe a foot or so from the end of the pipes, and they make good smoke.