Butter Fly's in the exhaust

[Jroch]

Greetings

Well tonight I figured I would be kind to my neighbors and try to fix the exhaust leak I have and found something interesting???? I dropped the exhaust at the manifold pipe. There was a spacer looking thing and in it there was a butter fly, it was not set up as a dump valve and there is know way to use it as that. Not really sure what it is, I have never seen anything like it? any ideas of what it is

 

[wrangler rider]

i your exhaust sounds different then other peoples i might say its for sound change like a whistle ?

yeah i was way off lol

 

[jeep cj7 304]

I think that is a sort of backpressure modulation valve, like this:Patent US5394901

 

[elwood blues]

Vroch, is that a V8 or L6?

If it's the V8, it's one of these;
Damper, Exhaust To Manifold (Includes Damper & Seal) 3238998 by the Jeep Specialists | Morris 4x4 Center

If it's a straight 6,
Exhaust Manifold 8124999 by the Jeep Specialists | Morris 4x4 Center

One way or the other, it's called an exhaust damper. With the stock air cleaner assembly, there's a piece of duct work that comes up from the outside of the exhaust manifold into the air cleaner duct. The idea is that when the engine is cold the damper is closed (not all the way), but it diverts some of that warm air up to the intake ducting to keep warm air to the carb to help the engine come up to temperature quicker.

On the straight six, it's built into the exhaust manifold, on the V8's it goes after one of the exhaust manifold, before the head pipe.

 

[IOPort51]

I believe that is what you call a heat riser valve, does it have some kind if spring and counter weight on the shaft end??

 

[mylittlecj5]

Its used to keep cold air from rising up thru the exhaust when the engine is shut off, so the hot exhaust valves don't get warped from the cold air hitting them. (a heat riser valve)

 

[kicknjeep]

IOPort51 nailed it, it helps send heat to your breather during warm up.

 

[IOPort51]

I think I like littles definition of purpose . kickin the one I think you are thinking of is in the air breather and activated bu the temperature/vacuum switch so it takes air off the "cook stove" on the exhaust manifold and directs it to the carb until the engine warms up.
I have never seen a heat riser valve that was not frozen open, which,I guess is much better than frozen closed.

It looks like the flange on the pipe that mates to the donut gasket has about bit the big enchilada.
a long time ago I tightened mine too tight and cracked it I had to weld grind and polish to get to seal again and it just cracked at the weld again, muffler shop couldn't form the flange so I had to form one myself. hammer former a flange on a short section of pipe by using a shot put for a dolly. this donut connection was one of the things that AMC did wrong, I haven't figured a way to improve it but it seems that the gaskets require replacement rather more frequently than I would like. I think splashing water on it when it is hot deteriorates it quickly.

 

[Jroch]

I think I like littles definition of purpose . kickin the one I think you are thinking of is in the air breather and activated bu the temperature/vacuum switch so it takes air off the "cook stove" on the exhaust manifold and directs it to the carb until the engine warms up.
I have never seen a heat riser valve that was not frozen open, which,I guess is much better than frozen closed.

It looks like the flange on the pipe that mates to the donut gasket has about bit the big enchilada.
a long time ago I tightened mine too tight and cracked it I had to weld grind and polish to get to seal again and it just cracked at the weld again, muffler shop couldn't form the flange so I had to form one myself. hammer former a flange on a short section of pipe by using a shot put for a dolly. this donut connection was one of the things that AMC did wrong, I haven't figured a way to improve it but it seems that the gaskets require replacement rather more frequently than I would like. I think splashing water on it when it is hot deteriorates it quickly.

Thanks for sharing your expierence with this as it's the exact same issue I am having went to the exhaust shop to see if they could do anything and they politely turned me away LOL still trying to find an old school shop to see if they can do something, one guy explained that they are to assist in the warming of the engine so that you can get it off "choke" faster. He went on to say thay he had never seen a functioning set, guess they freeze open.

At this point they are not affecting anything other then I have a noisy Jeep, I think what I am going to do is put a set of headers on it to eliminate them.

What motor are you running IOPORT

 

[Jroch]

Vroch, is that a V8 or L6?

If it's the V8, it's one of these;
Damper, Exhaust To Manifold (Includes Damper & Seal)*3238998 by the Jeep Specialists | Morris 4x4 Center

If it's a straight 6,
Exhaust Manifold*8124999 by the Jeep Specialists | Morris 4x4 Center

One way or the other, it's called an exhaust damper. With the stock air cleaner assembly, there's a piece of duct work that comes up from the outside of the exhaust manifold into the air cleaner duct. The idea is that when the engine is cold the damper is closed (not all the way), but it diverts some of that warm air up to the intake ducting to keep warm air to the carb to help the engine come up to temperature quicker.

On the straight six, it's built into the exhaust manifold, on the V8's it goes after one of the exhaust manifold, before the head pipe.

Elwood my jeep has a 343 out of a 1969 AMX