catted h-pipe and fumes?

[93project]

Simple question... Would a catted h-pipe cut down on some of the smell if I have zero emissions equipment? I've got a carb'd 331, TFS heads , long tubes, 3" cat back and the bbk short off road h. My car has always smelled but I'm just trying to cut it down a bit....

 

[gearheadboy]

It will cut down on some of the fuel type smell. You will get a lot more moisture out the pipes. Have you tried carb tuning?

 

[93project]

I had the carb tuned after I did my "tuning" its not overly bad.. Its about the same as when I was efi with no emissions.. The car is not running rich. Its got a good a/f. But, I just don't like having that smell on me when I get home as much as I used too...

 

[93project]

I'm also planning on dynomatting my interior to help seal it better... I have openings in the firewall that aren't plugged. I bought new door and hatch weather strip so that's helped

 

[jrichker]

More reasons to keep my EFI and smog equipment working correctly. It all shuts off at WOT (Wide Open Throttle) except for that cats, which cost maybe 10-15 HP. The small HP penalty is more than made up by the increased miles per tank of gas and the no stink smell of the car & driver. Soap and water to clean up the driver is cheap, but the gasoline has gotten expensive over the last 10 years...

 

[89stang1]

im running the same exaust longtubes with bbk shorty or h-pipe, and ive always been dealing with fumes too. After checking codes for and ignition problem i found i was also getting codes for 02 sensors, so i changed the two closer to front of car and it definitely made a difference but i live with whats left. BTW i have dynamat under entire interior and all door and hatch gaskets are newish yet i do get some fumes the worse when starting car in garage

 

[93project]

Thanks guys, well except jrichker, you always derail carb threads with your preachy efi sermons. We all know your feelings about it already.
Anyway, I'll add a catted h and see how it goes... Gotta sell off my off road first tho...
Love my carb!

 

[7991LXnSHO]

Ford was pumping air into the exhaust for many years before EFI. If you do not want the cats to clog, you will probably want a smog pump too.

 

[jrichker]

Thanks guys, well except jrichker, you always derail carb threads with your preachy efi sermons. We all know your feelings about it already.
Anyway, I'll add a catted h and see how it goes... Gotta sell off my off road first tho...
Love my carb!

I am licensed to preach...
And I do it every week....

 

[93project]

Sometimes daily

 

[7991LXnSHO]

A preacher and a mechanic? I guess the new testament guys all had day jobs.

My carb cars always start up quicker than the stock EFI ones, no matter what the weather. And the Carb cars are always cheaper to fix if they need a tune up or have some driveability issue. (I can do it myself.) Of course that is good - they need much more frequent tune ups compared to the EFI ones. Try finding a young mechanic who knows what to do with a set of points now. Even EEC-IV is a mystery for some younger mechanics! If I listen to enough sermons, maybe I will get to the point where EFI is just as easy too.

If you are having to go to all this work to avoid the stink, 1. the carb must not really be tuned that well or 2. there is a leak outside of the carb. That leak could be anywhere from the fuel cap, vent line, fuel lines, or the carb. What did you do about the fuel pump and do you have a pressure regulator?

 

[89stang1]

cats and smog pump=YUK! i dont care how bad it smells

 

[TOOLOW91]

Ford was pumping air into the exhaust for many years before EFI. If you do not want the cats to clog, you will probably want a smog pump too.

old converters needed it. new style usually don't need an air pump.

 

[jrichker]

A preacher and a mechanic? I guess the new testament guys all had day jobs.

Yes... fishermen, tax collectors. tent makers, political activists and me, a computer service tech for 35+ years.

old converters needed it. new style usually don't need an air pump.

Newer catalytic converters do not use the Thermactor Air System (smog pump) because they are designed to work with an improved computer system that runs leaner and cleaner
They add an extra set of O2 sensors after the catalytic converters to monitor the oxygen and HC levels. Using this additional information, the improved computer system adjusts the air/fuel mixture for cleaner combustion and reduced emissions. If the computer cannot compensate for the added load of emissions due to wear and poor tune, the catalytic converters will eventually fail and clog. The periodic checks (smog inspections) are supposed to help owners keep track of problems and get them repaired. Use them on an 86-95 Mustang and you will slowly kill them with the pollutants that they are not designed to deal with.

 

[93project]

Newer catalytic converters do not use the Thermactor Air System (smog pump) because they are designed to work with an improved computer system that runs leaner and cleaner
They add an extra set of O2 sensors after the catalytic converters to monitor the oxygen and HC levels. Using this additional information, the improved computer system adjusts the air/fuel mixture for cleaner combustion and reduced emissions. If the computer cannot compensate for the added load of emissions due to wear and poor tune, the catalytic converters will eventually fail and clog. The periodic checks (smog inspections) are supposed to help owners keep track of problems and get them repaired. Use them on an 86-95 Mustang and you will slowly kill them with the pollutants that they are not designed to deal with.

That's very good "non preachy" help on my question. Makes a lot of sense. So what if the car is driven less than 2000 miles a year? Newer cats wouldn't clog up too fast

 

[93project]

A preacher and a mechanic? I guess the new testament guys all had day jobs.

My carb cars always start up quicker than the stock EFI ones, no matter what the weather. And the Carb cars are always cheaper to fix if they need a tune up or have some driveability issue. (I can do it myself.) Of course that is good - they need much more frequent tune ups compared to the EFI ones. Try finding a young mechanic who knows what to do with a set of points now. Even EEC-IV is a mystery for some younger mechanics! If I listen to enough sermons, maybe I will get to the point where EFI is just as easy too.

If you are having to go to all this work to avoid the stink, 1. the carb must not really be tuned that well or 2. there is a leak outside of the carb. That leak could be anywhere from the fuel cap, vent line, fuel lines, or the carb. What did you do about the fuel pump and do you have a pressure regulator?

Fuel pump is an in line holley mounted under the spare tire well, just in front of the diff. Its regulated to 7psi. As for the tune, the car isn't running rich, it drives incredibly well, starts up great, idles great. To be honest, the smell isn't that bad, its just that I get a look and a "you stink" from my wife when I drive the car. As stated though, it was actually worse smelling when I had efi. Gt40 irons, no cats , mass air, whole 9. plus it idled like crap with efi and drove like a$$ in cold weather

 

[f8tlfiveo]

If you know your way around a carb and don't want to mess with efi that's fine. But if you were having trouble when it was efi, something wasn't right. My efi mustangs all have been well running machines. I never really had any issues with startup or cold weather driving. The efi system is designed to compensate for different temps and altitudes unlike a carb. It just seems like alot of work to swap a fox over to carb rather than fixing the efi prob. But to each is own I guess. How do you pass emissions?

 

[93project]

I didn't intend to remove the Efi... A lot of the problem was a severely damaged engine harness... I attempted to solder and repair it but it was fubar... So, carb.