Wet Black Soot Exhaust
 

My 38 runs well, however when I start the engine wet black soot shoots out the exhaust pipes. It makes a mess in the driveway. No drop in coolant or increase in oil. No gray smoke in exhaust. It does seem to be more than condensation. What is it?

Re: Wet Black Soot Exhaust
 

Since your not loosing coolant, the water has to be condensation and the black soot is most likely a rich burning condition. Pull several plugs and check for the soot deposits on them. If you baby the engine a lot or the carb has problems, the soot can build up. Depending upon the moisture in the air the there can be a lot of condensation.

Re: Wet Black Soot Exhaust
 

i had that till I blew the carbon out of her. rich idle condition contributed greatly. Ken ct rebuilt the carb. It was after that the soot quit showing up. I do run 100 miles a week at highway speed, 60-65. as for the water you can put 1/8 holes at the exhaust low point etc. but I'm not seeing that either anymore and I didn't drill the exhaust..

Re: Wet Black Soot Exhaust
 

Put a large bottle of Barr's heavy duty aiuminum stop leak in and it will stop. G.M.

Re: Wet Black Soot Exhaust
 

Barr's stops condensation in your exhaust? And carbon from a rich mixture?? ..B.

Re: Wet Black Soot Exhaust
 

would you happen to live in a damp climate? as I do, if so bk53 is correct and do pull the plugs to look at them. I have been using NGK and Autolite 216 with better results than the AC plugs for some strange reason also check for a good spark

Re: Wet Black Soot Exhaust
 

I have LOTS of old Fords and most did this and the Barr's stops it. On a cool day you will get a little condensation but what was described is a typical small leak. This mixes with the carbon in the pipes and muffler and makes the black mess. G.M.

Re: Wet Black Soot Exhaust
 

If you're running too rich, do you turn the jets in or out?

Re: Wet Black Soot Exhaust
 

the idle mixture screws ... in leans them out I think. I never got it right and finally had an old t-bird guy do it. he didn't say what he did but its perfect and so I ain't even looking at them. Somebody else here knowsd way more about it than i do. I think proper timing for your setup will make a big difference too.

Re: Wet Black Soot Exhaust
 

Set with vacuum guage. Rather than type it all, I pasted this.

http://www.chevyhiperformance.com/howto/45638/

Re: Wet Black Soot Exhaust
 

Aren't the idle mixture screws strictly for what they are called? Adjusting the idle. If you are running rich I would think that means you need to change your jet size or your choke is not open all the way. ?

Re: Wet Black Soot Exhaust
 

That only affects the idle mix. ken ct.:)

Re: Wet Black Soot Exhaust
 

Right as rain 4d. ken ct.:)

Re: Wet Black Soot Exhaust
 

Water is one of the products of combustion, and is most noticeable before the engine gets to operating temperature. It is still present at operating temperature, but not as a liquid. Warmup on choke adds the carbon, thus the typical driveway mess. Use thermostats and warm it up on the road. ..B.

Re: Wet Black Soot Exhaust
 

Actually the idle circuit continues to provide fuel at low load/low throttle angle driving conditions. So a rich idle can also lead to poorer gas mileage.

Re: Wet Black Soot Exhaust
 

Don't forget, Barrs Leak and MMO will fix almost any problem on a flathead.

Re: Wet Black Soot Exhaust
 

just curious about how long you are running your engine....trips??....getting engine temp up to normal and running it that way for a while??....thanks....Mike

Re: Wet Black Soot Exhaust
 

tom b

take off aircleaner.

start engine.

look down carb and make sure

you don't see gas pouring into engine.

that's stuck float.

use a bright flashlight and safety glasses,

in case of backfire.

bye

Re: Wet Black Soot Exhaust
 

So: What is it?:confused:

Will adjusting theese screws cure fouling/Carbon on plugs?

Thanks/Christian

Re: Wet Black Soot Exhaust
 

In..! If your still fouling plugs,rebuild the carb.

Re: Wet Black Soot Exhaust
 

Great! Will try that (thought it was out!):cool:

Re: Wet Black Soot Exhaust
 

Gasoline molecules are basically composed of some crazy arrangement of Hydrogen and Carbon. (It's a "hydrocarbon" material.) When gasoline burns in the presence of Oxygen, the Hydrogen and Carbon separate and they both combine with the Oxygen, forming "oxides." There are two forms of oxides of Carbon- Carbon dioxide (two atoms of Oxygen with one atom of Carbon, and Carbon monoxide (one atom of Oxygen with one atom of Carbon. If the mixture of gasoline and Oxygen is incorrect, there might also be small of plain carbon, or black soot. The oxide of Hydrogen is Hydrogen dioxide (water.) Since the oxides produce large amounts of heat, the water exists in the combustion chamber as steam and if the engine and exhaust system are hot, it will exit the tailpipe as invisible steam. When the engine is shut off, all of the steam that's in the exhaust system will condense into water droplets as the metal cools off and lie in the pipes and muffler until the engine is restarted, and then the new exhaust will blow the old water, and soot if there is any, out the tailpipe.

Re: Wet Black Soot Exhaust
 

One way to adjust the idle screws is to screw it in till the engine starts to stumble, then back off a half turn to a full turn. Do each idle circuit, one at a time.

Another way, and a better way is to use a vacuum gauge.

Re: Wet Black Soot Exhaust
 

Same instructions on a Stromberg would sure help.

Re: Wet Black Soot Exhaust
 

Is it just me, or doesn't anyone know that a combination of a little choke and cold exhaust pipes will result in wet sooty exhaust?

Re: Wet Black Soot Exhaust
 

What about 2 deuce, straight linkage? Do you hook up the vacuum and go in some series a little bit at a time until the vacuum drops off?

Re: Wet Black Soot Exhaust
 

Great answers! - I have experienced the soot and water from exhaust. Will try the adjusting.
But: IF car still fouling/sooting plugs after this, what can I do then? (except from buy a new carburetor, or car..) Have changed for warmer plugs (NGK 4)
Float level?

Re: Wet Black Soot Exhaust
 

it's been a while but on my 34 coupe the tail pipe ends were really black & sooty & the car did not run very well although it started & idled fine. That was whem\n I purchased it around 06 so forgive my PP memory. To get to the point the P O had an electric fuel pump & no regulator. I installed a regulator adjusted the float level & installed a new fuel hose from the regulator to carb & bumped the timing one notch. I had already installed a heavier battery cable 1/0 from the trunk located 6V battery to the starter as P O had 12V type wires & cable. Car runs as smooth as a well oiled machine can run. I do use MMO & marine sta-bil in the gas. Make driving a pleasure for sure. Oh no more black sooty exhaust tips.

Re: Wet Black Soot Exhaust
 

Have reduced mixture screws now to one turn from closed. This have eliminated a slight hesitation when picking up - now its as gentle as can be - a pleasure!

Not sure about the fouling yet. Will investigate.

However: now it backfires a lot...

Think I will go out and check float level now

Re: Wet Black Soot Exhaust
 

If you live where the air is moist it seems inevitable. 10 Years living in eastern Oregon with our 51 Merc. gave me two permanent soot spots on the driveway. Lots of time and money trying to correct a problem that wasn't really a problem. Always started and if we ran it long enough to get warm no fouling. Now that we have moved the car to Las Vegas she only marks her parking place with a small oil drip.

Don't sweat the small stuff have fun

Les Bliss
51 Merc

Re: Wet Black Soot Exhaust
 

I meant western Oregon.

Les

Re: Wet Black Soot Exhaust
 

Not sure how it can be a pleasure and back firing at the same time. :)

You might have a vacuum leak in the carb. But... You certainly need the right pressure and float setting first.

To get rid of the back fire, see if backing the idles out a turn will help first.

One turn out from seat, for me, only barely starts the car for a minute.But it is definitely a great starting point. Then you know both idles are at equal points.

It's certainly a combo of things to dial it in perfect.

Re: Wet Black Soot Exhaust
 

Remember the days when we burned leaded gas how the exhaust pipes were a light grey in color? We always thought that was the indication of a good engine and a well tuned one. Nowadays all exhaust pipes are black.