Exhaust/Frame Interference
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FTE Legend
Joined: Jul 2010
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From: Northeast, OK
Exhaust/Frame Interference
I have a clearance problem between the chamber ahead of the cat and the frame. Apparently didn't have that problem before having the heads machined as I don't remember having the bang/clang when I hit a bump. I worked on it a bunch today and got the gap up to 3/16" from 1/16 and that helped the noise quite a bit. But, I can't get any more clearance than that.
Anyone know of a source for exhaust pipes w/o a cat? Other ideas?
Anyone know of a source for exhaust pipes w/o a cat? Other ideas?
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From: Virginia
Loosen all 4 nuts that hold the y-pipe on, and jack the pipe up with a jack and then re-tighten the nuts(the ones that hold the y-pipe to the manifolds). The manifold/y-pipe connection is made to have some give in it and swivel around a little bit. A very little bit is all it would take by the time you get out to the catalytic converter.
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FTE Legend
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From: Northeast, OK
Thanks, but that's essentially what I did yesterday: Loosened the 4 nuts and all the other hangers to the rear; put a wedge between the frame and the chamber; tightened everything. When I pulled the wedge it went back some, but gave me 3/16" clearance instead of the 1/16" I had before.
If that chamber is really just to mix the just-injected air and exhaust, then I should be able to dent it to get more clearance - especially since I have no AIR injection system. However, if it has a catalyst in it then I could cause it to fail and, eventually, plug.
But, plugging is the only reason I'm concerned since we don't have inspections - which is why I could entertain a straight pipe.
If that chamber is really just to mix the just-injected air and exhaust, then I should be able to dent it to get more clearance - especially since I have no AIR injection system. However, if it has a catalyst in it then I could cause it to fail and, eventually, plug.
But, plugging is the only reason I'm concerned since we don't have inspections - which is why I could entertain a straight pipe.
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From: Virginia
It's definitely a converter and has stuff inside it, unless it's been gutted previously. One other thing you could try. You might have some play in the manifold to engine bolts. You could loosen all the bolt on both sides that hold the exhaust manifolds to the engine, and to the same routine again and see if you get anything out of it.
Also check your rear tranny mount.
Also check your rear tranny mount.
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Joined: Oct 2010
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Back when I was a teen (long time ago) when we would have a plugged cat or just wanted to have a more open exhaust we would yank the cat/con, run the biggest drill bit we had length ways through it shake out as much of the guts as possible and reuse.(WoW this reads like feline abuse) I think it would be just as easy to buy length of exhaust pipe cut to fit weld in place of cat.( We didnt have or know anyone with a welder), Just an Idea.
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FTE Legend
Joined: Jul 2010
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From: Northeast, OK
Ahhh, rear tranny mount. Now, that's something I missed. I'd been thinking about loosening the engine mounts to see if there's any way to tweak the position of the engine. But, it wouldn't take much movement of the rear of the tranny to get more space on the exhaust. And, there's a chance I have a bad mount somewhere.
The manifolds didn't appear to have any appreciable movement when I mounted them. And, they wouldn't seem to be able to move left or right w/o leaking - only up/down, which wouldn't seem to help with side-to-side clearance. Right?
So, are both of the chambers catalytic? Both of them have heat shields, but why two cats? Just due to the lack of room for a big one?
Yes, if I had the proper "straight pipe", although it would be anything but straight, I could cut out and weld it in. In fact, I'd been thinking of getting the tool from HF that expands pipe to allow it to fit over another one, so maybe this is the time - except that I'd still have the problem of needing a bend in it.
The manifolds didn't appear to have any appreciable movement when I mounted them. And, they wouldn't seem to be able to move left or right w/o leaking - only up/down, which wouldn't seem to help with side-to-side clearance. Right?
So, are both of the chambers catalytic? Both of them have heat shields, but why two cats? Just due to the lack of room for a big one?
Yes, if I had the proper "straight pipe", although it would be anything but straight, I could cut out and weld it in. In fact, I'd been thinking of getting the tool from HF that expands pipe to allow it to fit over another one, so maybe this is the time - except that I'd still have the problem of needing a bend in it.
