I drove my '67 fastback around 100 miles today. My lungs hurt and I'm short of breath. The car is a little rich, not a lot rich 331 with 343 rwhp. YES I know cat's didn't come out untill '76 however I want to run them on my 'stang is there anyway? yes I understand that I'll loose a couple of hp. it's better than a few years off of my life. how long will cats live with out a pump?
cat's with out pumps!
- Thread starter usedtobe 67p51d
- Start date
89MustangGX
I have nothing productive to add!
I would tend to look back a little bit and see why you are "suffocating." Maybe you have an exhaust leak, or you don't have the tailpipes oriented correctly? I know I've personally ridden in plenty fo cars without cats and never even smelled the exhaust unless I got out of the car while running. All this is aside from the fact that those cars never came with them -- you shouldn't need them!
Cantslowdown
New Member
You can put cats on there. But man if its that rich to burn your eyes and stuff trying tuning your car. Are if you have dumps run the pipes to the back.
lots of cars run cats with no smog pump. it sounds like you really need to tune the thing though. a well-tuned car should run clean w/o cats ( i know you know this)...but with as rich as you are running, they wont last long.....
Michael Yount
Mustang Master
Please tell us more about your engine so we know what we're dealing with - carbed? EFI? In any event, the catalytic converters won't solve your mixture problem - if I were you I'd work on that separately and try to get the engine working with reasonable a/f ratios before you put your cats on.
The emissions systems on cars are designed to work in concert -- all the pieces work together. Generally speaking, the EFI uses feedback from O2 sensors to keep the air fuel ratio in a pretty small range - so that the catalytic converter has the capacity to catalyze further oxidation in the exhaust stream AFTER the products of combustion have left the combustion chamber. By carefully controlling the mixture with efi and feedback from the O2's, the amount of harmful emissions the cats have to clean up is limited. Specifically, there are oxides of nitrogen (NOx), unburned hydrocarbons (HC - if you're rich, you've got lots of these), and carbon monoxide (CO) - these are the 'harmful' controlled emission products. The emissions systems are designed to reduce these. The cats are constructed in a way that they speed up additional chemical reactions when the harmful emissions (above) pass over the ceramic matrix inside the cats - turning most of the harmful HC, CO and NOx into harmless CO2 and H2O. In order for those chemical reactions to occur, excess oxygen needs to be present in the exhaust stream - and that's what the air pump does - it provides the excess oxygen necessary for the cats to do their job by pumping air into the exhaust system. Matt90 - the airpump is DEFINITELY there for the cats - both components work together to reduce emissions. But here's the thing - the cats don't work so well when the mixture gets a long way off from what they were designed for, and they also don't work well when there's no excess oxygen for the chemical reactions the cats support. So, cats without excess oxygen (air pump) and mixture control may not work like they're supposed to. EDIT - as cars have gotten newer, and fuel injection systems and combustion chamber design has gotten even better at controlling the mixture and resulting products of combustion, many newer cars have been able to do away with the need for the air pump. But that doesn't mean it's not required to optimize an older system.
So, just throwing a set of cats on thinking it's gonna help "burning lungs and shortness of breath" probably ain't gonna work - it's likely only to result in burning lungs, shortness of breath, and a shortness of cash in your wallet.
The emissions systems on cars are designed to work in concert -- all the pieces work together. Generally speaking, the EFI uses feedback from O2 sensors to keep the air fuel ratio in a pretty small range - so that the catalytic converter has the capacity to catalyze further oxidation in the exhaust stream AFTER the products of combustion have left the combustion chamber. By carefully controlling the mixture with efi and feedback from the O2's, the amount of harmful emissions the cats have to clean up is limited. Specifically, there are oxides of nitrogen (NOx), unburned hydrocarbons (HC - if you're rich, you've got lots of these), and carbon monoxide (CO) - these are the 'harmful' controlled emission products. The emissions systems are designed to reduce these. The cats are constructed in a way that they speed up additional chemical reactions when the harmful emissions (above) pass over the ceramic matrix inside the cats - turning most of the harmful HC, CO and NOx into harmless CO2 and H2O. In order for those chemical reactions to occur, excess oxygen needs to be present in the exhaust stream - and that's what the air pump does - it provides the excess oxygen necessary for the cats to do their job by pumping air into the exhaust system. Matt90 - the airpump is DEFINITELY there for the cats - both components work together to reduce emissions. But here's the thing - the cats don't work so well when the mixture gets a long way off from what they were designed for, and they also don't work well when there's no excess oxygen for the chemical reactions the cats support. So, cats without excess oxygen (air pump) and mixture control may not work like they're supposed to. EDIT - as cars have gotten newer, and fuel injection systems and combustion chamber design has gotten even better at controlling the mixture and resulting products of combustion, many newer cars have been able to do away with the need for the air pump. But that doesn't mean it's not required to optimize an older system.
So, just throwing a set of cats on thinking it's gonna help "burning lungs and shortness of breath" probably ain't gonna work - it's likely only to result in burning lungs, shortness of breath, and a shortness of cash in your wallet.
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