1956 soot comes from exhaust

[cviater]

Black carbon-like “soot” comes from exhaust when starting. This 56 T’bird was in the shop for about a year. Wondering if this is just a build up in the exhaust system or does the engine need some maintenance after sitting for such a long time.

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[biddle]

Use the 4-digit model year in the subject as prompted on your future posts. Also you can omit the make/model of the car to shorten your subject since we are exclusive to Ford Thunderbirds.

 

[Ward 57]

Black carbon-like “soot” comes from exhaust when starting. This 56 T’bird was in the shop for about a year. Wondering if this is just a build up in the exhaust system or does the engine need some maintenance after sitting for such a long time.

Most likely normal carbon build up. Being started and moved around a lot would not let it warm up enough to pull off the choke. I wouldn't worry unless it continues after several start up and drive cycles getting up to full temperature for a while.

 

[74 Harley]

It can also be from over choking, if it doesn't go away.

 

[CtCarGuy]

I think most of what you are seeing is the rich mixture on startup. You may want to lean out the choke a little. I just had my teapot carb rebuilt and other than some black moisture, it starts clean.

 

[Shawnski]

Black carbon-like “soot” comes from exhaust when starting. This 56 T’bird was in the shop for about a year. Wondering if this is just a build up in the exhaust system or does the engine need some maintenance after sitting for such a long

After sitting that long, they always have that issue. Once you start driving it and getting it up to temp, it goes away.

 

[Frankie the Fink]

I think most of what you are seeing is the rich mixture on startup. You may want to lean out the choke a little. I just had my teapot carb rebuilt and other than some black moisture, it starts clean.

This is the answer, its pretty typical of vintage carbureated cars of the era and not something to loose sleep over.

 

[Goldwinghg]

Black carbon-like “soot” comes from exhaust when starting. This 56 T’bird was in the shop for about a year. Wondering if this is just a build up in the exhaust system or does the engine need some maintenance after sitting for such a long time.

That is pretty common,on these old cars with a carb. They offer a electronic fuel injection in place of the carb. The seems to help alot. You turn the key. It start right up. No smoke or soot. Pretty pricey,but they do stsrt,start, run better.

 

[Frankie the Fink]

My two four barrel 61 Corvette spewed a bit of soot out after every cold start up and I would track the nastiness into the house and get a "talking to" fromt the wife about it - I put rubber mats under boths sides of the car at the rear to mitigate it.
This is PERFECTLY NORMAL for old carbureated muscle cars that start up quire rich when cold (assuming a working choke). Do NOT worry about it. When the hot exhaust first passes through the cold exhaust, condensation forms and eventually is evaporated as the car warms up; but it will leave behind a sooty residue inside the pipes that gets blown out on the next cold start up.

I certainly wouldn't go to one of those electronic carbs (called aftermarket fuel injection in the ads) because of it; you'll have a whole host of new issues, like linkage fabrication in some cases, fuel line routing, hood clearance, tuning for best operation, etc.