Condensation

[Spittybug]

I think it was Bitsyncmaster that mentioned something about this previously, but I'll ask anyway. What is it about our cars that makes them spit such a large volume of water out of the tailpipes? I went for a few spins today to dial in my acceleration enhancement with the Megasquirt. After shutting the car down for a few minutes to analyze the data and makes some tweaks, I started it back up and let it idle while I checked a few more things. The engine was at temp at this point. Both tailpipes are spitting water out all over the garage floor. Of course the carbon residue is leaving nice little black spots. They'll clean off the painted floor fine, but why so much moisture? It's a dry, cool day here in Houston. Do all cars create this much water? Maybe our cars are just better at purging it before it cooks up and comes off as vapor? I was surprised that the system wasn't so warm as to just evaporate it since I'd already put several miles on the car before I started it up this second time.
Odd.

[DMCMW Dave]

What is it about our cars that makes them spit such a large volume of water out of the tailpipes?

Our exhaust system (compared to a regular car) is extremely short. I think that gives the moisture more chance of condensing out for some reason. I'm not really sure why but that's a big difference. Any physics guys out there?

[Bitsyncmaster]

I only see the water drops spitting out the tail pipes during a cold engine warmup. I notice it on the cement floor and can not leave anything near the tail pipes during warm up.

[Ryan King]

http://www.youtube.com/watch?v=uGSsuEhORlA

http://www.youtube.com/watch?v=uGSsuEhORlA

[David T]

All cars with internal combustion engines produce a lot of water as a by-product of combustion. You only notice it when the exhaust system is cold because it condenses inside on the cold metal till the exhaust warms up. At that point it is water vapor and you don't see it anymore. Many cars have small holes located at strategic low points in the exhaust system so the water will not collect and rot out the metal parts. One of the reasons you should always get the motor to operating temperature and not run it for just a couple of minutes once in a while during storage. Very common on commuter's cars doing a short drive to the train station or carpool lot to destroy an exhaust system quickly. If you start seeing a lot of white smoke and have to add coolant often you may have a blown head gasket. The reason for a lot of the water is that the motor is using the atmosphere for combustion oxygen and the atmosphere (air) contains a lot of water vapor. Some water is also created during the combustion process. As the weather gets colder it becomes more noticeable, especially on older cars that do not warm up fast. Deloreans do not seem to be any better or worse than most.
David Teitelbaum

[LEVY]

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Catalytic converters produce water on all vehicles equiped with this device, our vehicles have a very short distance from the catalytic converter to the tail pipes, thus giving the water no chance to evaporate, other cars, on the other hand have a lonng distance and allow evaporation, even those drop water from the tailpipe. Vehicles withy CC removed should not have this problem, any coments from members with CC removed?


Levy

[DMCMW Dave]

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Vehicles withy CC removed should not have this problem, any coments from members with CC removed?


Levy

I don't really consider this a problem, but it does show why, in climates where you store the car for the winter, just running the engine in your garage for a short while every couple weeks is a bad idea. By springtime you'll have a gallon of water in the muffler.