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Corvair Center Forum :
Corvair Center Phorum - presented by CORSA
![]() Corvair Center Re: Catalytic Converters Posted by:
Marco_a_p
() Date: January 08, 2021 04:09PM Keep in mind that modern fules are not the same as they were in the "good ole days" Fuel is more volatile and evaporates more rapidly then back in the day. Hence why modern cars have a "Closed" fuel system. Pressurized by evaporating fuel etc. Marco A 2nd Gen Monza Wagon, a 2nd Gen GB 8door, a 2nd Gen (61's were 1st Gen) R/s and a 62nd Gen Turbo coupe.. Hanging out with the scorpions, king snakes, road runners, coyotes and quails In the southern desert of the silver state Mesquite NV 89024 Re: Catalytic Converters Posted by:
CoCoCo
() Date: January 08, 2021 04:32PM I was able to buy a couple of Magnaflow cats a couple of years ago from one of the local O'Reilley's with no trouble. A friend's brother works there, but I don't think that had anything to do with the availability since they were either in stock, or were delivered to the store within a day. Paul Re: Catalytic Converters Posted by:
Brizo
() Date: January 09, 2021 08:34AM KenHenry Wrote: ------------------------------------------------------- > 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. Does your '51 Ford still have the open crankcase vent pipe? If so, the passengers may be smelling blow-by vapers coming through holes in the firewall. Excess fuel pressure may cause hot soak flooding leading to vapor leaking into the car also. ? Dan Brizendine, Circle City Corvairs '64 8 door Greenbrier, +.060, stroked 1/4", 186 ci.140 PG. "In beautiful Wanamaker Indiana...with one stop light and 5 pizza shops" Re: Catalytic Converters Posted by:
KenHenry
() Date: January 09, 2021 09:21AM Fuel percolation after shutting down was always an issue, and one of the reasons I converted it to EFI (Megasquirt with Ducati fuel injectors). I also set up a PCV system for it so I think the remaining smell is mostly unburnt hydrocarbons due to the rich idle. The idle gets choppy when I try to lean out the idle, wonder whether it would work better with port injection... ![]() Ken Henry, Rochester, NY USA 1965 Corvair Corsa 140 hp, 4 speed Re: Catalytic Converters Posted by:
alphasud
() Date: January 09, 2021 09:40AM Combustion chamber design is the reason you can’t run lean. I think in your case a good old fashioned thermal reactor to do with the HC is all you could do. I know on the air cooled VW’s if you leaned the idle below 3% CO the HC’s would start climbing from the misfires. David North Idaho 1965 Corsa Turbo converted to 140 1971 Super Beetle with 2.5L Subaru engine 1988 Citroen CX 25 GTI Turbo Re: Catalytic Converters Posted by:
wittsend
() Date: January 09, 2021 02:50PM Quotes by cschneider53 "...but my tolerance for the smell of unburned fuel is a lot different than it was 20 years ago." "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." As I've re-read all of this it seems like the main complaint is "unburned fuel" and it comes after he enters the garage. I mean even if he has to "power" into the garage how many seconds is the engine running to do so.., two seconds (and likely with the exhaust pointing out the door)? The cost of EFI and CATS seems rather pricy for the few seconds the Corvair drives in the garage to eliminate an odor - if it even would. Is CATs in this case like putting a tourniquet around the neck for a nose bleed? A few have mentioned evaporating fuel and I'm inclined that is (at least the greater part of) the real problem. Whether from a fuel leak, evaporating fuel in the float bowls (most likely), fuel tank venting etc. A hot oil (leak or otherwise) can also contribute "vapors," especially in the absence of a PCV system. Perhaps a greater analysis by the poster and more information would help to reasonably solve the problem. Re: Catalytic Converters Posted by:
didget69
() Date: January 11, 2021 06:23PM Most muffler shops in my area that are 'quality' shops can install an aftermarket cat, even with thin washcoat, that will last their 24 month / 24k mile warranty period. I was the recent 'recipient' of a cat hack-attack,on a Honda Element (top 10 candidate for a cat-ectomy...) and local shop replaced cat with aftermarket for $300 installed with 24/24 warranty - and I'm fine with that. They've always stood behind their work, and guarantee no emission/exhaust related codes for warranty duration. Local garages trust their Cat work to this one shop... and have for over 20 years. bryan in NC Re: Catalytic Converters Posted by:
cschneider53
() Date: May 19, 2022 10:42AM Bringing this topic back from the dead… A few tings have changed. I’m back in CA, I have Ted’s EFI running well and have been daily driving my Vair with the wonderful spring weather. It has a wideband lambda and there is still some fuel curve adjustment that is ongoing. The fuel smell sitting is not really much of an issue but the exhaust is still an annoyance especially if I’m sitting in traffic with the top down. I can monitor the AFR in real-time and even at 14.7 it’s still smelly. The motor is very tight with excellent compression (as it should after a full rebuild only 400 miles ago). The 260 cam does provide for a slightly lumpy idle and I certainly would be just fine with less exhaust noise. Will I really mess something up if I have a local muffler shop weld on some cats? Re: Catalytic Converters Posted by:
Seth Emerson
() Date: May 24, 2022 11:35PM Remember that the catalytic converter process creates heat. You will have to add insulation and/or shielding near where you choose to position the converter. And it cannot be too low either. Stay safe. Seth Emerson Check my new Performance Corvair Web site: [www.perfvair.com] Located in lovely San Jose, California Re: Catalytic Converters Posted by:
alphasud
() Date: May 25, 2022 07:39AM With the Ted Brown EFI and running at stoch. You should be able to fit a cat or cats and be okay. With a Corvair you will be close enough to the heads to light the cats quickly. Bear in mind aftermarket cats only have a portion of the metals that a factory cat has. Even in the best environment a replacement cat is only good for 15K-30k miles. If you can find a good used one they will be more robust and even more efficient. Bear in mind even the best cats won’t last long when the engine exceeds 10% leak down numbers. David North Idaho 1965 Corsa Turbo converted to 140 1971 Super Beetle with 2.5L Subaru engine 1988 Citroen CX 25 GTI Turbo Re: Catalytic Converters Posted by:
cschneider53
() Date: May 25, 2022 08:30AM Talked with the local muffler shop the other day and the owner said he’s done a number of classic car cat installs for the same reason. When I told him I had a Corvair he said it’s possible but where to actually fit them is going to be the challenge. Good thing is he’s owned four Corvairs over the years so at least I’m starting with someone who has familiarity. Re: Catalytic Converters Posted by:
scottymac
() Date: May 26, 2022 04:45PM joelsplace Wrote: ------------------------------------------------------- > "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, You neglected to mention option #7 - get rid of the woman. That's what I chose, though in hindsight, all your options are cheaper. Much. Scott Danville, In. '65 Corsa coupe basket case '66 Monza coupe ![]() Re: Catalytic Converters Posted by:
CoCoCo
() Date: June 02, 2022 11:30PM A vent and electric fan in the garage might also be a helpful modification. Could be less expensive (depending on the fan and how much work you farm out to someone else) but worth it for the other benefits. Cooler summers maybe... Paul Re: Catalytic Converters Posted by:
guthrie1068
() Date: June 03, 2022 03:29AM Joel is cracking me up... I installed an exhaust fan in the garage for this very reason, and it helps. I also leave the garage door up for awhile after I park. Lastly, I have an old furnace fan that moves a lot of air, sometimes I'll plug that in and aim it out of the garage. Chad Guthrie Rives Junction, MI '63 convertible Re: Catalytic Converters Posted by:
cschneider53
() Date: June 05, 2022 07:32AM It's still at the muffler shop. He's waiting on parts to dry fit and see if anything will be small enough to work. Re: Catalytic Converters Posted by:
cnicol
() Date: June 05, 2022 08:44AM One thought: Is your PCV hooked up and functioning correctly? Crankcase fumes account for about half of the aromatic, unburned HC produced by an engine and they can be a significant source of foul odors in the cabin. If crankcase fumes are allowed into the engine compartment, they're sucked into the fan and distributed to the cabin through leaky heater seals when the heater is off and more so if the heater is on to any degree. This is the problem created by so many when they put a little air filter on the end of the crankcase vent instead of routing the fumes to the air cleaner. Craig N. Coeur d'Alene ID. 66 Black Monza 4dr, 4.2L V8 49k 61 Seamist Jade Rampside 140 PG 65 Canadian Monza 4dr 110/PG 40k 66 Sprint Corsa convt - First car! Re-purchased 43 years later 2+2 gnatsuM 5691 +17 Tons of parts Re: Catalytic Converters Posted by:
cschneider53
() Date: June 06, 2022 05:42PM That’s an excellent point Craig! As soon as I get the car back I’m going to deal with that too. Re: Catalytic Converters Posted by:
ROD
() Date: June 06, 2022 07:07PM Install one of these you won't smell a thing Rod Tetrault El Cajon , CA 65 Corsa Yenko Clone / 65 Corsa EO Creampuff Vert 66 Corsa "JIMISH" Mid engine Turbo LS1 currently 2nd fastest Corvair in the USA Corvair powered Buggy x 3 Enough hidden parts to build a space ship ![]() Attachments: ![]() Re: Catalytic Converters Posted by:
63turbo
() Date: June 06, 2022 07:14PM cschneider53 Wrote: ------------------------------------------------------- > That’s an excellent point Craig! As soon as I get the car back I’m going to deal with that too. You might be suprised at how much having a good PCV system gets you in terms of de-stinking the engine compartment, especially at low speeds. The key is to have the crankcase gasses go to the intake manifold, not to the aircleaner! One of the neat side benefits of systems like that are that the annoying seeper oil leaks are dramatically reduced. ------------------------------------ Kevin Nash Friday Harbor Washington 63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com] first test start on EFI here:[www.youtube.com] first official EFI boost test here:[www.youtube.com] My new fan! [corvaircenter.com] engine less 62 Spyder Canadian 64 Monza Parts car Test Start#2 [www.youtube.com] ![]() ![]() ![]() Re: Catalytic Converters Posted by:
RexJohnson
() Date: June 06, 2022 07:23PM I believe that the car has a real PCV system. That is a hole to let clean air into the oil fill tube and another using a PCV vale out of the original hole to the balance tube to get rid of the bad stuff. It would be like the one on Craig's rampside. RJ tools Salem,Oregon ![]() Sorry, only registered users may post in this forum. |