Catalytic converter fit in 1982

[Zedman]

Hi All- I would like to get some direction on replacing a Catalytic Converter in my 1982 Avanti II. My vehicle is undergoing a frame transplant and yesterday, I removed the Catalytic Converter before we start cutting off mountings, 'X' frame and other hard-points for welding into a replacement Studebaker Lark SWB chassis.

I have two questions-

My friend, who is assisting me with much of the work, commented on the very poor presentation of what appears to be a clearance cutout in the RH side frame rail bottom flange to accommodate one corner of the original Cat Converter.  He believes that the Cat is not original and 'butchery' was performed to clear it, because " the presentation of the lousy weld doesn't compare with the other weldments on the Frame, and I don't believe its a factory job". This cutout is indeed a poorly presented piece of work, but I told him the Cat is original as there is a picture of the same type on page 45 of John Hull's book. So my first question- to settle an argument-  is, was this lousy rough cut-out indeed a Altman & Newman era factory procedure?  We are taking great pains to ensure we replicate my new frame in great detail but we're damned if we are going to reproduce this clearance cut. Picture-

Next question- Can anybody advise as to a replacement for this original, very flat Catalytic converter and does it essentially need the EGR system pipe attachment?  I don't believe I'm going to get away with deletion of the Cat when I finally road register the car so I will be needing a replacement.

Regards Steve, RQB3269

[Jim78]

Yep, that's a factory butcher job.  My '78 is the same way.  I suppose if one were looking for true "authenticity", he should hack his frame.  🙄  Others might see this as a good opportunity to lose the cat entirely and use straight dual pipes.  The more environmentally conscious owner might consider two in-line aftermarket converters.

https://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?q=catalytic+converter+universal&storeId=10001&catalogId=10002&langId=-1

[Gunslinger]

If your state allows it I would do as Jim78 says...lose the cat and install a true dual exhaust with low restriction mufflers.  Also...as he says...you can buy aftermarket cats and install them but only if you really want them.  

Installing a true dual exhaust will do wonders for performance in most cases...especially if you increase the pipe diameter from the factory pipes to 2 1/4" or 2 1/2" diameter.

[arkus]

i recently installed a complete exhaust on my '80. i got everything but the mufflers from dan booth. in vermont cats are necessary to pass yearly inspection. we don't have a "sniff test" and they don't have to be original, only there. i bought two small, inexpensive cats from summit and re-engineered dan's system to install them by themselves, no additional mufflers. being also a hot-rodder, i appreciate a good throaty exhaust note, but the sound was, i thought, a little aggressive for an avanti so i re-engineered the system again and installed an additional pair of 24" glass packs. just right!  took the better part of a day but was quite straight forward and required no welding. dan's installation kit was helpful.  about moon roofs; this car has only 56k on it and has never leaked a drop! i've had others that would give you a shower. go figure.

[pantera928]

4 hours ago, arkus said:

i recently installed a complete exhaust on my '80. i got everything but the mufflers from dan booth. in vermont cats are necessary to pass yearly inspection. we don't have a "sniff test" and they don't have to be original, only there. i bought two small, inexpensive cats from summit and re-engineered dan's system to install them by themselves, no additional mufflers. being also a hot-rodder, i appreciate a good throaty exhaust note, but the sound was, i thought, a little aggressive for an avanti so i re-engineered the system again and installed an additional pair of 24" glass packs. just right!  took the better part of a day but was quite straight forward and required no welding. dan's installation kit was helpful.  about moon roofs; this car has only 56k on it and has never leaked a drop! i've had others that would give you a shower. go figure.

So does your 1980 perform better now or just sound better to your ears?

[pantera928]

14 hours ago, Zedman said:

Hi All- I would like to get some direction on replacing a Catalytic Converter in my 1982 Avanti II. My vehicle is undergoing a frame transplant and yesterday, I removed the Catalytic Converter before we start cutting off mountings, 'X' frame and other hard-points for welding into a replacement Studebaker Lark SWB chassis.

I have two questions-

My friend, who is assisting me with much of the work, commented on the very poor presentation of what appears to be a clearance cutout in the RH side frame rail bottom flange to accommodate one corner of the original Cat Converter.  He believes that the Cat is not original and 'butchery' was performed to clear it, because " the presentation of the lousy weld doesn't compare with the other weldments on the Frame, and I don't believe its a factory job". This cutout is indeed a poorly presented piece of work, but I told him the Cat is original as there is a picture of the same type on page 45 of John Hull's book. So my first question- to settle an argument-  is, was this lousy rough cut-out indeed a Altman & Newman era factory procedure?  We are taking great pains to ensure we replicate my new frame in great detail but we're damned if we are going to reproduce this clearance cut. Picture-

Next question- Can anybody advise as to a replacement for this original, very flat Catalytic converter and does it essentially need the EGR system pipe attachment?  I don't believe I'm going to get away with deletion of the Cat when I finally road register the car so I will be needing a replacement.

Regards Steve, RQB3269

Get an aftermarket cat that fits so you do not have to recreate what was never a great idea in my opinion. THere are newer, smaller and more efficient cats out there than were available back then.

My hats is off to you for doing a frame replacement. It would take me several flats of VB to get through that job🍻

[Zedman]

Thanks for the feedback this far everybody....  Pantera, thanks for the kudos mate - we do have a bit of a drink after each work session but it's never VB (rubbish, there is far better than that to be had nowadays !  😋).  As Gunslinger suggests- I would prefer to do away with it- mainly based on the available space (the original was one skinny bugger).  Our legislation states that cars pre 1986 manufacture don't need a Cat, BUT on another line elsewhere states that if the car was manufactured using a Cat, it is to retain it. I'm preparing for one scenario but hoping for another. Bottom line is I don't want a s@!t fight with Vicroads when I go for club registration. Futher query... will it matter if the EGR system is not connected to it if I do replace the Cat  with one without provision for such ?

Steve

[Gunslinger]

Again...depending on your state laws and assuming they have special license plates for antique or historic cars, the car may be exempt from emissions regulations.  If that's the case you can do as you like.  You'll have to check with the state for that.  

EGR systems existed before catalytic converters so whether you keep it may have no effect otherwise...not sure of that.  I used to have a '78 Corvette that I got rid of the cat and installed a true dual exhaust, got rid of the EGR and the car ran great.  

[pantera928]

13 hours ago, Zedman said:

Thanks for the feedback this far everybody....  Pantera, thanks for the kudos mate - we do have a bit of a drink after each work session but it's never VB (rubbish, there is far better than that to be had nowadays !  😋).  As Gunslinger suggests- I would prefer to do away with it- mainly based on the available space (the original was one skinny bugger).  Our legislation states that cars pre 1986 manufacture don't need a Cat, BUT on another line elsewhere states that if the car was manufactured using a Cat, it is to retain it. I'm preparing for one scenario but hoping for another. Bottom line is I don't want a s@!t fight with Vicroads when I go for club registration. Futher query... will it matter if the EGR system is not connected to it if I do replace the Cat  with one without provision for such ?

Steve

What is better in your opinion? Not Tooheys

[Zedman]

Anything else!...we recently tried a Carlton breweries "Black Ale"....damnn good 🙃