Cat Converter Tube - Federal

Post by **ARCHINSTL** » Tue Oct 25, 2005 5:02 pm

I would appreciate someone looking at their Federal catalytic converter tube in the engine bay, and comparing it with mine in the photo. This is the tube leading forward from the converter, that has the filter and reed valve in it. Apparently only Federal vehicles have this.
The FSM does not have a photo (or even an accurate drawing) of the entire tube, and mine looks pretty kinked at the bend by the block, under the oil filter. I would think that the final portion of the tube would be at 90 degrees from the block, but mine is off by quite a bit, leading me to think that it was bent back at some time, leading to the pretty good kink at the bend.
It still sucks (some) air, but would obviously suck more if the kink were a normal full-diameter bend. I just do not know if the quantity is important. It would be possible to cut the tube and just use a piece of rubber tubing to be the final piece.
Thanks to all respondees !
Tom M.

coltarms · Post by **coltarms** » Tue Oct 25, 2005 5:30 pm

Do you mean using rubber right next to the cat??? It would most likely melt awfully quick..... I Don't think it would matter what the material was at the end opposite the cat, as long as the chosen material doesn't let off any particulates that could cause problems with emissions testing....

I have a hole in the little pipe that comes off my cat.... I need to figure out a good way to patch it. Muffler mud worked for about 2 weeks. Muffler bandage has a hard time wrapping around a pipe of that small diameter. Duct tape melts. Any suggestions other than welding? (I don't have a welder...)

Post by **ARCHINSTL** » Tue Oct 25, 2005 6:25 pm

Thanks for the reply.
This tube - and the kink - are beneath the oil filter, and nowhere near the converter. There are already rubber tubes in this steel tube, between the reed valve box and the filter and connecting the filter with the bent pipe in question (not in photo, though).
What you can use to cap the little tube exiting the converter requires visiting the plumbing/gas fittings section of your big box hardware store. The OD of the little tube on my replacement converter was 13mm, as I recall. I used a modified gas fitting to match it up to the OEM long tube (leading to the left front - tube in my post). I did this because I wanted to keep the system complete, for emission testing purposes. But I know you will find something to cap it in the fittings section. Also check in electrical conduit fittings.
Tom M.
P.S. When I get this thing past the inspection, I will post some pix on my adaptation of the aftermarket converter to the OEM air suction tube thingie.

Typrus · Post by **Typrus** » Tue Oct 25, 2005 10:06 pm

Thats no stock bend. My 86 Fed had a semi-mandrel bend. Mandrel enough that I couldn't see any diameter change.

Fingers · Post by **Fingers** » Tue Oct 25, 2005 11:51 pm

Yeah Tom,

I couldn't see why you couldn't use some high temp rubber hose. Since it is drawing in cool(er) air, it should be alright. A few years back, I had a Chrysler that had a rubber hose that came directly off the cat. Don't know what type of hose it was, but the dealership told me that was how she came from the factory. At 80,xxx miles it was toast. Luckilly (?), the car went to hell before I even had to worry about it.

Yeah, post some pix, I know that the parts store offers a kit of some type to adapt the aftermarket cat to the stock air tube, but I haven't checked them out yet. Probably a hunk of rubber hose and a few clamps....

Fingers

Post by **ARCHINSTL** » Wed Oct 26, 2005 12:40 am

Thanks, guys.
I will cut the tube and patch in either another metal tube, or more likely, use a piece of rubber tubing. The rubber should be no problem, as there are already two of this material in the routing. The only heat will be that thrown off by the block. The little tube on the new converter itself is about 1/3 +/- of the diameter of the OEM tube, so really a lot of air was not getting through. This did not look right. Who knows - this may help in passing the emissions test...
Tom M.

Post by **ARCHINSTL** » Thu Oct 27, 2005 9:34 pm

Well -
I don't imagine anyone else will/does have this problem, but I will post a pix anyway.
I would NOT advise anyone doing it this way: Just too darned hard-I will not mention how long it took to force the tube through under the AC compressor, but suffice it to say some time... Of course, if the compressor was not there, it would have been considerably easier. Also, you cannot remove the bracket which holds the tube to the block without removing some of the PS lines - not a problem with no p-steering units, though.
I will revise this in the Spring and sweat in a 90 degree copper plumbing pipe and longer copper tube, similar to the OEM one. But for now, the 5/8" ID washing machine hose will have to do. This hose is really stiff, which is why I could not get it to bend 90 degrees like the OEM tube, but had to run it forward under the compressor and up against the (non-operative) AC fan. I was also unable to force it onto the tube stub all the way, per the pix, but it is secure.
The OD of the OEM tube is 17mm, which is close enough to the 5/8".
Anyway - the mod seems to work - it feels like there is more air being sucked into the converter...
Tom M.

takza · Post by **takza** » Fri Oct 28, 2005 3:41 am

Those converters get MAJOR hot....if you smell burning rubber..... :blink:

Post by **ARCHINSTL** » Fri Oct 28, 2005 12:03 pm

Actually, there are two other hoses before this one.
The long metal tube leaves the converter and goes forward 3 feet or so to the reed valve (which is welded into the tube). Then a rubber hose connects to the bulbous filter, and then another hose connects the filter to the L-shaped tube (which was the crimped one in my instance). So the newly spliced-in tube I did is at the end.
Tom M.

takza · Post by **takza** » Sat Oct 29, 2005 3:18 am

Those reed valves can get insects and so forth lodged in them...I modded the opening for the air source so unfiltered air can't get into the valve...just used some duct tape.

If they mess up...you get an exhaust noise.

Post by **ARCHINSTL** » Sat Oct 29, 2005 2:26 pm

takza -
Interesting that you mentioned filtering the air, which is why I ran the tube into the AC fan shroud. I figured that would take care of any road debris/etc. I had not considered actual insects, though.
Anyway, when I installed the new converter, the tube came off with the converter (OEM welded in place), and so I had to modify it to work with the new converter. I checked/cleaned the reed valves - the reeds give an interesting key of ? when you blow through the tube :wacko: , but fortunately found few fauna (actually none, but I could not resist the alliteration...).
Since the car is originally from TN, perhaps MootsMan can verify the existence of arthropods in Nashville's environs?
Tom M.

Typrus · Post by **Typrus** » Sat Oct 29, 2005 2:38 pm

Takza- There is no rubber for a few feet of pipe. Don't worry about the heat. The first rubber connection is connected to, if I remember right, the starter where there is a bracket connecting to the lengths of tube. That rubber looked very in tact on my 86 Fed.
I never fully understood the purpose of the air tube....? Its not on my 84 Cal, so when I put the Fed engine in the 84 Cal, I eliminated the setup as I didn't want to figure out how to swap the converters over.

Post by **ARCHINSTL** » Sat Oct 29, 2005 3:14 pm

Since the wonderful FSM is mum on the subject, I would presume that the purpose of the tube apparati is to introduce extra air into the converter for more complete combustion of the noxious vapors?
I have casually wondered why the Federal version has this tube but not the California version - I always thought that California was the more anal about exhaust nasties...
Also, why does the Fed version have the HAC valve, and not the Cali version? I did not think the mountains in Cali were shorter than the Ozarks or Adirondacks, etc.
Tom M.
P.S. Typrus - I hasten to add that the Rockies are not shorter...

takza · Post by **takza** » Sun Oct 30, 2005 1:47 am

I have the Cal version...the air injection thing is different...doesn't go into the cat...goes in sooner...right after the cast iron header.

The air source for mine is inside the air cleaner on the bottom...for some reason 1/2 the opening is outside the filter...so I taped over this part.

Had to clean the reeds out 2xs because of this allowing stuff to get pulled into the reeds...leaving them open all the time. This is a problem if you are off road a lot...bugs, leaves, etc.

Post by **ARCHINSTL** » Sun Oct 30, 2005 2:08 pm

takza -
NOW I understand your earlier post. I wondered how bugs (save perhaps gnats) could get sucked into that small tube which opened up next to the lower fender in the bay.
I had forgotten you had the Cali version. After looking at the FSM I see how your intake could have accepted items. The FSM has only a line drawing of the intake, so I guess we can only wonder why the aperture is only partially enclosed.
This is actually virtually identical to that of my Federal '88 Dodge/Mitsu pickup's system, save for the placement. There was a failure of the reed valve, and it was allowing the exhaust to enter the air cleaner housing (and carb), and kept melting the little secondary filter in the intake, and partially melting the big cleaner. The truck also ran like crap - talk about EGR ! The mechs that had installed the new engine had no clue why the thing ran so poorly and the MPG was waaay down. I finally figured it out, so just ran a piece of conduit from the reed valve's exit to the front of the engine, and sealed up the cleaner housing. Voila! The Jasper engine ran as it should have, and the MPG went back to the new-car of 23+/-.
It also passed the emissions test with flying colors - of course, the tech did not look under the hood, or else it would have failed for sure. The converter is now only partially processing the exhaust, of course, and the thing is spewing exhaust instead of sucking air in, but the reed valve assembly is pushing $300 from the Mitsu dealer. My bad...
Tom M.
P.S. I wonder if a similar failure, even partial, could be a source of current problems with some Cali/Canadian versions of the 3AC? Worth checking the reed valves, I guess.