Blackwater - home remedies?

[Bob Riding]

No, not the 70's Doobie Bros song -the stuff coming out of my tailpipe on the '40 wagon. I know why- It know doubt ran rich as I over carbed it with 2 Carters for 5 years. Now I've switched to Langdon's Weber 32/36 clone and it runs pretty good, except every time I start it up I get sooty water out the exhaust from carbon buildup. I've taken it out and "opened it up" - full throttle,  a number of times- but still have the black stuff (exhaust is clean, light gray). Any home remedies that proved effective? I've heard spray water into the carb, Seafoam, etc. 

[Ivan_B]

That looks just like my setup - 40 tail pipe with water stains and cardboard to the left 😅

Sorry, I don't think you can do much about it. Other cars will do this too, depending upon the configuration of the exhaust, its age, and other factors. My newer fuel injected vehicle does not spit out of the pipe but it has a small rusty hole at the bottom of the front edge of the muffler and the black water comes out of there every-time you run it. Sometimes, a lot of water comes out 🙄

Edited Saturday at 05:12 PM by Ivan_B

[Los_Control]

I was thinking water myself, is known to "steam clean" the inside of a engine and remove carbon ..... I need to try this myself.

 

I have seen some just dribble it into the carb from a bottle while keeping engine at a fast idle .... others use a spray bottle and squirt it in.

Rev up the engine and watch the black soot pour out of it.

 

While I do use seafoam annually in my fuel tanks .... I'm a bit skeptical on how well it works inside the engine from the oil. ... It might help.

 

Currently I'm running about a quart of ATF with my oil to help clean sludge and hopefully unstick some rings .... not your problem though, but is a good cleaner on internal engine parts. .... I just feel I would get more benefit adding ATF to my oil then I would seafoam.

 

I use the ATF by adding it to the oil before changing ... run it awhile like a week or so, loosens things up.

Then change oil and add a quart ATF to the fresh oil and run it for a few weeks to really clean the engine good, then change it again .... depending how clean the oil comes out determines if I keep adding ATF .... is a good cleaner and a quart will not damage the engine.

[Sniper]

It's carbon, a byproduct of burning hydrocarbons.  Modern cars have cats that run at high temps to help ameliorate that.

 

Probably jetted too rich still.  But just using the choke will richen it up anyway.

[greg g]

We used  to say  it needs an Italian tune up.  Make suree your choke is fully open, at high idle pour about 1 quarter can of Berrymans carb cleaner slowly down the carb, pour about half of whats left in the can into the gaa tank.  Now drive out to the country roads then drive the wheels off it till you run about about a quarter tank through it. 60 to70 miles or so. Get every thing g nice and warm then let her eat.  In the words of Enzo Ferrari, "Brakes?  We don't need brakes!  They only slow you down!"  Make sure you use all the carb circuits, idle, acc pump, climb so long hills to get the step up valve gets some work. Speaking of the step up, if it's not working correctly it might be stuck open, which will cause wet exhaust, black smoke, lousy fuel milage and fouled plugs.  What do your sparkplug look like?

[kencombs]

IMHO, nothing fed into the carb inlet will do much of anything beyond the exhaust manifold.   Water and/or alcohol will clean the combustion chambers well, but the resulting loose carbon will get deposited in the muffler.   The exhaust just cools too much beyond the manifold.  

 

 

The 'italian tuneup' is likely the best solution, but wait for nice warm weather and find a location with lots of uphill runs to get as much temp increase as possible for as long as possible.   And repeat weekly.

[FarmerJon]

 As much as I like engine cleaners and Italian tuneups, I dont think they will get any of the soot out of the tailpipe(s). 

Some soot is natural, but if the weber is giving a better air/fuel ratio, it should be much slower to build up. 

 

I would fashion something that you can swab out the tailpipe with. Think gun brush, but broomstick based. You may be able to find a bottle brush of the correct size at a hardware store or on Amazon, but a rag stapled to a broomstick would also work. 

I would get the exhaust nice and hot, then stick the wet swab up the pipe a few times. 

 

Of course this will only get it clean for the foot or two before it loops over the axle, and you may find that black water from deeper in the system still runs out. Maybe a few cleanings will remove enough of it that it isnt splattering your bumper and garage floor.

Good luck!

[Ivan_B]

Guys, are you seriously advising the "Italian tuneup" on a 1940 American car? 🙄 

Also, to clean the engine sludge out - use synthetic oil with detergents, and change often, works very well.

Also #2, seafoam will just evaporate from the oil before you know it.

[oldodge41]

On 1/11/2025 at 5:07 PM, Sniper said:

It's carbon, a byproduct of burning hydrocarbons.  Modern cars have cats that run at high temps to help ameliorate that.

 

Probably jetted too rich still.  But just using the choke will richen it up anyway.

Word of the day is "ameliorate". I looked it up. Learn something new everyday. LOL

[Sniper]

Sorry I spent a lot of time out at sea. I read every book on the ship that wasn't a tech manual and started reading the dictionary.

[Plymouthy Adams]

reading the dictionary could likely induce stuttering......c-c-c-c-c-c-c-c-c-c...

[Dan Hiebert]

The only way to reduce the "black" is to reduce the carbon.  Either the production of, or buildup of.   That is what the aforementioned remedies do.  The water itself is inevitable, that is just condensation from the combustion process working its way through the exhaust system.  New cars spit water, too. 

[p15-1948]

I wonder if the new setup is still too rich?

[Bob Riding]

12 minutes ago, p15-1948 said:

I wonder if the new setup is still too rich?

Good question. What would be the best way to find out? I do have this beast that I've been wanting to play with...

[Dave72dt]

Does it have a probe for the exhaust gases?  That machine should have been hooked up and used for all your tuning and diagnosis on pre- OBD cars and could be used for some aspects on those.  That oscilloscope provides a wealth of information.

[Bob Riding]

No tailpipe sniffer, or vacuum gauges. Electrical only- 

[greg g]

I wasn't referring to the color of the pipe, I was referring to the moisture drops  on the driveway. Some condensation is to be expected, but if it is chronic it indicates the exhaust is running cold.  The Italian tune up is just a way of encouraging lengthy bouts of extended spirited driving within of course  the limitations of the brakes,  tires and traffic and operator's handing iimits.

Edited Tuesday at 09:00 PM by greg g

[greg g]

Ameliorate is a big word for extend, increase, accelerate, enhance, or to render enfavorable changes and or conditions.