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Current Page: 3 of 4
Re: Catalytic Converters
Posted by: 67 airvair ()
Date: June 07, 2022 05:11AM

My first thought on this thread was that it should be labeled OT - off topic. After all, we are concerned with Corvairs, which never had catalytic mufflers.

My second thought, after seeing someone ask as to how to put them on a Corvair, was WHY?

My third thought is that, unless you are an automotive engineer with the proper test equipment and lab, you are really guessing as to what the results, good or otherwise, are going to be, as these things are best designed by a qualified engineer in the field. Having an engineering degree, I see and can understand this point probably better than most on this forum.

At this point, I am brought back to question #2.

-Mark

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Re: Catalytic Converters
Posted by: slow61 ()
Date: June 07, 2022 05:21AM

67 airvair Wrote:
-------------------------------------------------------
> My first thought on this thread was that it should be labeled OT - off topic. After all, we are concerned with Corvairs, which never had catalytic mufflers.
>
> My second thought, after seeing someone ask as to how to put them on a Corvair, was WHY?
>
> My third thought is that, unless you are an automotive engineer with the proper test equipment and lab, you are really guessing as to what the results, good or otherwise, are going to be, as these things are best designed by a qualified engineer in the field. Having an engineering degree, I see and can understand this point probably better than most on this forum.
>
> At this point, I am brought back to question #2.
>
> -Mark


Similar thoughts could be had on any number of modifications done to Corvairs or any other cars for that matter.

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Re: Catalytic Converters
Posted by: jjohnsonjo ()
Date: June 07, 2022 07:41AM

I find this an interesting topic. At one time I thought about putty one on my turbo, mostly to increase the EGT which drops off a lot in our systems. This isn't rocket science. I have gone though two wood stoves with CATS.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 12, 2022 08:37AM

I'm super happy with this result. The engine note is more pleasing (less "clacky") and the "sweet" smell of unburned hydrocarbons is essentially eliminated. The catalytic converter is made by Flowmaster and is 8.25 inches long, 2.5" inside diameter to fit the custom two-into-one exhaust on my 140hp. I tacked it in place and then completed the welds on the bench. Note that my muffler is a little shorter than a stock Corvair muffler. This engine is running a custom EFI Megasquirt setup so typical AFRs are 13-14 and richer at WOT. Ken

9D5AE45F-B68C-426B-945F-5C85D4A72AD8 by kenhenry_06268, on Flickr

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: SpyderMan ()
Date: June 12, 2022 10:03AM

Wow, that looks great. I am am putting that on my list to try with my wagon.

Sam Russell
Durham NC
1962 Monza Wagon Ted Brown EFI Gen II
1964 Spyder coupe


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Re: Catalytic Converters
Posted by: wittsend ()
Date: June 12, 2022 10:43AM

Originally the negative to me was the cost (even if it is other peoples money). Here in California we HAVE to buy California Certified CATs that typically cost 3-4 times what a 49 State CAT cost. So, that was the price rattling in my head when you proposed this. The other was the carbureted A/F ratio rendering the CAT ineffective in short order. But now seeing you have an EFI system, it is only one CAT (I was thinking dual exhaust and the cost of two) and likely not a California priced CAT this seems a very favorable project. I would assume if the wife is smiling you will know the system is still working,

While the world certainly needs engineers it also needs people willing to step out and give something different a try. In that thought of 'stepping out' two very impacting films on my young life were the original "Flight of the Phoenix" and this audience applauding scene from the film "Airport" Mr. Petroni - GET OUT! . smiling smiley

------------------------------------------------------------------------------

***'61 Lakewood, a "Freebie" in hibernation for 27 years - In the process of applying CPR.***

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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 12, 2022 11:06AM

Part number 2000125 is what I used. $82 and not for sale in CA unfortunately. Ken

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: June 15, 2022 08:09AM

Thanks Ken! Nice looking setup. I just sent your picture over to my muffler guy. He promised me he's going to get going on it this week and he's pretty confident he will have something that works.

The CA cats are quite a bit more expensive but that isn't simply a CA tax with no benefit. The additional cost is directly related to the wash coat. CA requires much more liberal wash coats for the cats to be certified. This means higher prices in the beginning but also means longer life and greater efficiency at catalyzing.



Edited 1 time(s). Last edit at 06/15/2022 08:13AM by cschneider53.

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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 15, 2022 01:43PM

Thanks! Here's my PCV setup. It uses a 93-2001 Lexus GS300 3L PCV valve and uses a fresh air inlet from the air cleaner to the oil fill tube. I was initially getting some oil spray up the tube and into the air cleaner (pre rebuild, lots of blow by) which was corrected with a small baffle inside the alternator/oil filter adapter. Now the only issue is I need to pull the PCV valve out of the breather coupler to add oil without it rudely burping back at me!! The base of the PCV is wrapped with friction tape for a good seal. Ken

E579F7F0-0BEE-4DAA-B0FE-752FC2630C58 by kenhenry_06268, on Flickr

E98983F5-EDFF-401D-ADEF-238D2B9D2612 by kenhenry_06268, on Flickr

843BF116-38D0-43E0-B885-CC82D2C7DBE9 by kenhenry_06268, on Flickr

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: June 21, 2022 03:10PM

Here's the completed system. Looks real clean. Huge thanks to Ken for posting pics of his setup. Hopefully I get a few good days of driving out of it before the meth heads come with the sawzall.




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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 21, 2022 04:26PM

Wow, that looks amazing! 1. How’s it smell? 2. How’s it sounds? Very clean install

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: June 21, 2022 04:31PM

KenHenry Wrote:
-------------------------------------------------------
> Wow, that looks amazing! 1. How’s it smell? 2. How’s it sounds? Very clean install

I haven't even picked it up yet. My muffler guy took the pics on the rack. I sent him your pictures and as you can see, he basically copied your setup with a subtle change on the Y.

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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 21, 2022 04:57PM

Nice! So he made a big single for your 140hp? I copied the basic plan from info posted on here by Al Lacki, just added the cat. Looking forward to the full report !! thumbs up best, Ken

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: Paulsgt ()
Date: June 21, 2022 04:59PM

This is pretty cool! If I do an EFI I would consider adding a cat. You guys have such nice clean installs! It'll be interesting to know if you have heat problems back there. Those cats need to get really dang hot to work properly. Might cause problems for air cooled cars. Maybe some sort of heat shield?

Vairy cool stuff guys!

Enjoy the Corvair!

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


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Re: Catalytic Converters
Posted by: KenHenry ()
Date: June 21, 2022 05:04PM

All is can say is that the engine is not running any hotter based on my gauge. That said a heat shield might be prudent thumbs up

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Catalytic Converters
Posted by: alphasud ()
Date: June 21, 2022 05:11PM

I used header wrap on my converters when I installed the Subaru engine in the Bug. Worked fine. Also used a thermal barrier on anything close to the cats.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1988 Citroen CX 25 GTI Turbo

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: June 21, 2022 06:01PM

I thought about a heat shield but I’m going to wait and see for now. With the Nashfan, my temps are really low so I wouldn’t be surprised if I can get away without worrying about a shield.

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: July 03, 2022 03:38PM

It finally cooled down enough in the Bay Area for me to take the vair out and not start sweating within seconds. The setup definitely does what it was designed for as far as the smell goes. It's gone. Smells like a 90s era vehicle now. The problem with the setup now is that it drones way too much for me. With the single muffler it's a thunderous exhaust note. I'm sure there are some who would love the sound, just not me. Definitely looks like I'll have to spend some more money and go to dual.

The goal is to muffle as much as possible. Two things I'm wrestling with are whether to keep the crossover and turn downs.

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Re: Catalytic Converters
Posted by: American Mel ()
Date: July 03, 2022 03:52PM

I would say that the problem is not the number of mufflers, but rather the SIZE.
That looks like a fairly good sized tail-pipe.
Something a bit smaller will quiet it down, more than adding another muffler of the same size..

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WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: Catalytic Converters
Posted by: jjohnsonjo ()
Date: July 03, 2022 05:25PM

When GM was designing the turbo Vair, they did a lot of experimenting with different mufflers. They discovered that the length of the exhaust tip had a great deal to do with the sound. Once they got the correct length for the turbo exhaust tip they could run a nearly wide open muffler. This still works as I have played with it over the years.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Current Page: 3 of 4


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