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Catalytic Converters
Posted by: cschneider53 ()
Date: January 08, 2021 08:48AM

Anyone running cats on their Vair. I saw at least thread from a member but it was a decade ago.

I know they don't need them and I have no smog requirements in WA but my tolerance for the smell of unburned fuel is a lot different than it was 20 years ago.

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Re: Catalytic Converters
Posted by: RobertC ()
Date: January 08, 2021 09:05AM

Get an exhaust gas analyzer and adjust your carbs.

Will not be as clean as a new car, but a lot cheaper.

Catalytic converters will not last long on a rich running engine anyway.

Might look for exhaust leaks?

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Re: Catalytic Converters
Posted by: wittsend ()
Date: January 08, 2021 09:08AM

cschneider53 Wrote:
-------------------------------------------------------
... my tolerance for the smell of unburned fuel is a lot different than it was 20 years ago.

As much as I hate to admit it I nearly choke at car events, especially in the summer from venting fuel bowls. Hard to believe there was a time when gasoline seemed like a manly cologne.

Unfortunately without the precise control of EFI a CAT probably wouldn't last too long.

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: January 08, 2021 09:54AM

After I've had some time with the engine running well, I'm considering going to Ted's EFI with wideband lambda sensors. I figured this would pair well with a set of cats to make it bearable for my wife to have the Vair in the garage. I can roll it out to start but can't roll it in after shut off because of the slope of the driveway.

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Re: Catalytic Converters
Posted by: KenHenry ()
Date: January 08, 2021 10:01AM

I put Flowmaster catalytic converters on my 1951 Ford flathead V8, mostly to quell passenger complaints as these engines engine need a fairly rich idle (~12.5:1) even with EFI added and sealing of the passenger compartment is poor. I have a WB02 mounted and cruise and light acceleration are fairly lean.

They worked great for a few thousand miles over 2 months but now the exhaust stink is back and as bad as ever. I don't think they are plugged - just not functional.

One limitation: they were mounted 4 or 5 ft down the exhaust system due to space limitations and may not have run hot enough to live a long life! Maybe one would last longer closer to the manifolds but hard to know. These are fairly inexpensive cats as well which may be a factor.

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

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Re: Catalytic Converters
Posted by: joelsplace ()
Date: January 08, 2021 10:30AM

They do have to be closer to the engine. The OEMs use stainless in front of the cats to keep the heat up even when run close to the engine. Some engines have the cat bolted right to the head.
The smell in the garage - are you sure it isn't raw fuel? Lots of people complain about that. The hot engine boils off the fuel in the carburetors and smells. Heated fuel in the lines can also push into the carburetors on hot soak.
Fuel injection would fix all that except for the fuel tank vent.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Catalytic Converters
Posted by: 66vairman ()
Date: January 08, 2021 11:06AM

I've mentioned before that younger folks near an idling old car DO comment on the "stink".

There is a trend to make restomod old cars run cleaner with new engines or electric conversion. I suspect the cost of making a Corvair engine "clean" and have it perform well is not practical. So you'll probably see electric conversions keep them going on the road.

I remember the carburetor/catalytic converter era before EFI and those cars were awful due to poor driveability and mediocre fuel economy.

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Re: Catalytic Converters
Posted by: SpyderMan ()
Date: January 08, 2021 11:27AM

I have been thinking about this for my wagon that has the gen2 Ted Brown EFI. It is much better as as far a smell goes but I wondered if a cat would eliminate the little bit of smell that is left.

The EFI eliminates the after run smells completely and I have been amazed how much of the bad heater smell was carb related. I am still running a road draft tube but I have everything gathered to add a PCV system. This plus the cat I think might eliminate 95% or more of the odors.

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


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Re: Catalytic Converters
Posted by: KenHenry ()
Date: January 08, 2021 11:28AM

I've seen many OEM converters mounted several feet back from the exhaust manifold, sometimes with a closer pre converter as in Fox bodied Mustangs, and so had hoped it might work. The Flowmaster 200 series converter was about $70 so probably not great quality. You should have not trouble getting a converter nice and hot with the short Corvair exhaust system, though finding enough space for one could be tough! The main objectional fumes from my Corvair are from when oil drips on the exhaust.

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



Edited 1 time(s). Last edit at 01/08/2021 11:30AM by KenHenry.

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Re: Catalytic Converters
Posted by: Timothy Shortle ()
Date: January 08, 2021 11:44AM

I just heard from my tenants (auto repair shop complex) that someone showed up in the night with a saw and removed a bunch of converters (over 10) from customer cars left outside. It is a mess to say the least. Somehow I thought this topic might be about the theft of this valuable auto part.

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Re: Catalytic Converters
Posted by: cschneider53 ()
Date: January 08, 2021 11:49AM

Timothy Shortle Wrote:
-------------------------------------------------------
> I just heard from my tenants (auto repair shop complex) that someone showed up in the night with a saw and removed a bunch of converters (over 10) from customer cars left outside. It is a mess to say the least. Somehow I thought this topic might be about the theft of this valuable auto part.


Maybe I'll check craigslist for some killer deals on lightly used ones. spinning smiley sticking its tongue out

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Re: Catalytic Converters
Posted by: wittsend ()
Date: January 08, 2021 11:49AM

KenHenry Wrote:
-------------------------------------------------------
> ... The Flowmaster 200 series converter was about $70 so probably not great quality. ...

Not sure where the original poster lives but in California you can only buy certified CAT's. And those sell for about $350 (smaller, very common cars) upwards of $800 each depending on application. I took a quick look and it doesn't appear you can buy many, if any generic CAT's.

I wonder when they say you can't "sell or USE this Convertor in California" how that works for a car that doesn't need one. I mean going by the (ridiculous) letter of the law you would be in violation.



Edited 1 time(s). Last edit at 01/08/2021 11:50AM by wittsend.

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Re: Catalytic Converters
Posted by: Timothy Shortle ()
Date: January 08, 2021 11:53AM

I believe the Calif. law is only for cars with OBD II (1996 and newer). Before that aftermarket parts are acceptable. I also believe the thieves sold these to a scrap yard and then purchased (drugs?).

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Re: Catalytic Converters
Posted by: American Mel ()
Date: January 08, 2021 11:56AM

KenHenry Wrote:
-------------------------------------------------------
> I've seen many OEM converters mounted several feet back from the exhaust manifold, sometimes with a closer pre converter as in Fox bodied Mustangs, and so had hoped it might work. The Flowmaster 200 series converter was about $70 so probably not great quality. You should have not trouble getting a converter nice and hot with the short Corvair exhaust system, though finding enough space for one could be tough! The main objectionable fumes from my Corvair are from when oil drips on the exhaust.


You are correct, as I have seen this also. (My first vehicle was a Chevy Van, and the Cat was at least six or seven feet from the manifold!)
I am thinking that many of these vehicles also had smog-pumps that introduced fresh Oxygen just ahead of the Catalytic Converter.
That extra Oxygen might be the key to getting that truly hot burn in the Cats on your Ford.
But then again, just using a Smog-Pump might be enough to burn off that excess unburned fuel?
THAT IS what they were designed to do!
I know that nobody wants to install power robbing devices on their Corvair, or any other Classic for that matter.
BUT I wonder, of those that still have Factory Smog-Pump Set-ups on their car, how many of them are complaining of Stinky Exhaust?
Is it possibly just that simple?

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
'65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dually, approaching 400K
'03 Honda Del Sol
17'Terry
[corvaircenter.com]



Edited 2 time(s). Last edit at 01/08/2021 12:02PM by American Mel.

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Re: Catalytic Converters
Posted by: joelsplace ()
Date: January 08, 2021 12:04PM

"I can roll it out to start but can't roll it in after shut off because of the slope of the driveway."
There are several ways to fix that:
1) Get good at coasting and carry enough speed to make it into the garage so you can kill the engine beforehand.
2) Install a winch in the garage.
3) Leave the garage door open for a few minutes after you pull in.
4) Install an exhaust fan in your garage. A timer triggered by a garage door opener would be good.
5) Build a detached garage.
6) Move.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Catalytic Converters
Posted by: wittsend ()
Date: January 08, 2021 12:05PM

Timothy Shortle Wrote:
-------------------------------------------------------
> I believe the Calif. law is only for cars with OBD II (1996 and newer). Before that aftermarket parts are acceptable. I also believe the thieves sold these to a scrap yard and then purchased (drugs?).

Unfortunately no. I just did a check on a very generic 1990 Honda Civic (OBD I for sure) at Rock Auto and they still require C.A.R.B approved CAT's (though they are less than I have seen for other certified CATS).

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Re: Catalytic Converters
Posted by: alphasud ()
Date: January 08, 2021 12:48PM

Many factors to consider before installing a cat on a Corvair. Most important is to have good fuel control so efi and either a O2 sensor or wideband is a must. Also running the engine as close to stoch. I.e. 14.7:1 will make the cat the happiest. Also the engine has to be tight with leak downs less than 15% otherwise the excessive blow-by will coat the matrix in the cat and render it useless. And last but not least you get what you pay for buying aftermarket cats. The cheaper cats have a thinner wash coat of the precious metals so they don’t last very long. In fact when I replace cats on modern cars I have had aftermarket cats still create a check engine light BC they are ineffective. I don’t think you will have to worry about the cat being too far back on the Corvair unless you have the tail pipe coming out if front of the front tire.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1965 Corsa mid engine project
1973 Mercedes 280 project

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Re: Catalytic Converters
Posted by: SpyderMan ()
Date: January 08, 2021 12:59PM

Do we think an OEM cat for a 2 liter or bigger would flow enough for my 145ci motor? I know that our short stroke motors are just under 2.4 liters.

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


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Re: Catalytic Converters
Posted by: KenHenry ()
Date: January 08, 2021 01:04PM

As an alternative I've considered handing out activated charcoal masks to people who complain about the smell!!

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

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Re: Catalytic Converters
Posted by: Timothy Shortle ()
Date: January 08, 2021 01:13PM

A C.A.R.B. (California Air Resource Board) approved part can be an aftermarket part. My mothers 1995 Volvo got a "direct fit" catalytic converter that was an aftermarket part so it would pass an emission test.

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