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dilligaf 11-20-2012 05:35 PM

liquid from exhaust
 
I am getting a lot of liquid mixed with carbon from the exhaust pipes. It seems to be way to much for condensation. The inside of the pipes are coated with black soot. This problem was there with the old exhaust and the new exhaust that I just had done. It blows out when I first start the engine cold and after I have ran the engine for several miles. The temp after several miles was at 195. I am running a 650 Edelbrock on a small block with a mild cam. I mention this because all along I thought it might be raw gas mixing with the soot in the pipes.

painted jester 11-20-2012 06:04 PM

Its normal, moisture from the air is turned to steam in the cylinders and condenses in the exhaust pipes and muffler and is then forming water droplets at the exit of your tail pipes and carbon collects there street mufflers have small weep holes in them to drain this condensation! Dont worry till you get clouds of heavy white steam that's usually damage!! Larger carbs and cams increase the moisture drawn in with more air and you see more at the tail pipe! Mine blows smoke rings with the lumpy cam my grand son thinks its cool LOL But when pipes all get hot you wont see the steam but as long as the pipes are cool the water will condensate! The longer the pipes the longer it takes to get hot!!

Jester:thumbup:

poncho62 11-20-2012 06:10 PM

Quote:

Originally Posted by painted jester (Post 1613760)
Its normal, moisture from the air is turned to steam in the cylinders and condenses in the exhaust pipes and muffler and is then forming water droplets at the exit of your tail pipes and carbon collects there street mufflers have small weep holes in them to drain this condensation! Dont worry till you get clouds of heavy white steam that's usually damage!!

Jester:thumbup:

That said, with the black soot and it having a Holley, its a good bet that its running a bit rich

painted jester 11-20-2012 06:13 PM

It could be the choke is opening late too causing a rich Idle! When cold!! Or not opening all the way!

Poncho its a 650 Edelbrock, but it doesn't make any difference your right!

Jester

oldbogie 11-20-2012 07:25 PM

Quote:

Originally Posted by dilligaf (Post 1613753)
I am getting a lot of liquid mixed with carbon from the exhaust pipes. It seems to be way to much for condensation. The inside of the pipes are coated with black soot. This problem was there with the old exhaust and the new exhaust that I just had done. It blows out when I first start the engine cold and after I have ran the engine for several miles. The temp after several miles was at 195. I am running a 650 Edelbrock on a small block with a mild cam. I mention this because all along I thought it might be raw gas mixing with the soot in the pipes.

A bit more than half of the exhaust is water vapor from the combustion of gasolne. The chemical formula looks something like this:

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

What this is saying in chemists shorthand is that 2 molecules of octane is reacting with 25 molecules of diatomic oxygen (the way oxygen is found in the atmosphere) to make 16 molecules of carbon dioxide and 18 molecules of water. This is perfect reaction of octane and oxygen from the air, in reality the chemistry of gasoline has other stuff in it like benzene, toluene, zylene all stuff best not gotten on your skin. Also, there isn't time inside a running engine for these reactions to complete so there's always some unburnt hydrocarbon left over and carbon monoxide that didn't have time or the free oxygen to burn to carbon dioxide. In addition the atmosphere is mostly made of nitrogen while this doesn't contribute to the reaction at high temperature it will combine with oxygen to make the many types of nitrogen oxides shown as NOx in the common press. Oxygenates are added to the gas to provide some extra oxygen without leaning the mixture to help the hydrocarbon and CO to CO2 burns to get at completion, today's love affair is with ethanol (grain alcohol) in the past they used methyl tert-butyl ether (MTBE) which is a throughly dangerous material you sure don't want on you and has mostly been banned, worked really good though.

The carbon can be from too much cold running to where it doesn't burn off. Or it can be from a rich mixture; this could be too much or too long on the choke, too much fuel pressure, too high a float setting, power valve (metering rod) comes on too early, the intake manifold is too cold, engine coolant and running temp is too cold, the ignition is not powerful enough resulting in miss and late fires, the air filter is dirty or in the case of K&N type oil wetted gauze being too oily.

Lots of choices to go look at.
Bogie

lakeroadster 11-20-2012 08:02 PM

Great thread. "2 C8H18 + 25 O2 → 16 CO2 + 18 H2O" Pretty cool when Chemistry = Stuff I have observed!

I put true duals on my C10 and have noticed it too tends to exhaust a lot of moisture when I first start it. Initially I was concerned about a blown head gasket. I keep a close eye on the oil (no signs of water) and on the radiator (no drop in antifreeze level).

Additionally the moisture in the exhaust that ends up on the concrete driveway evaporates away, no signs of antifreeze. I guess all's well that end's well?


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