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Topic Review (Newest First)
08-16-2002 12:53 PM
Mertz Here is a quote from the Corvair Forum concerning the water decarboning.

"Posted by Ken Schifftner on August 16, 2002 at 13:26:45.

In Reply to: Re: Water in the carb debate posted by Matt N. on August 16, 2002 at 10:11:54.

I certainly agree with Matt.

We've done the water cleaning trick a couple or three times at the Coyote Club meetings. We even came up with a fogger nozzle that blows a mist into the carburetors (if the idea of pouring water slowly into them makes you squeamish). You don't want to hydraulically lock the engine with water.

What actually happens, I'm told, is that CO (carbon monoxide) is produced more than any blasts of steam. This technique is also used (sometimes with ammonia addition) on incinerators to help burn out carbon. Since extra CO is produced, you should certainly do this outdoors.

It does work.
An old mechanic who lived near me in NJ when I was growing up would start every tuneup with, first, an inspection of the plugs, then he'd replace them and do the decarbon ritual."
08-16-2002 07:27 AM
WoodsEdge DMorris, I also remember when the thing to do was pour trans fluid in carb,60s-early 70s. It was supposed to clean carbon from everything. Also remember running 4 quarts oil and 1 quart trans fluid in engine to prevent sludge. Don't know how well all this worked but I did put 200,000 on a 66 289 before I sold it. Still had good power and used no oil between changed
08-16-2002 04:14 AM
dmorris1200 Well I'll definately agree that you can always tell which cylinders were leaking by the nice clean pistons. But I wonder if that's a result of the anti-freeze properties or would it create the same result if it was straight water.
08-15-2002 09:46 PM
juxtoposed I do agree that pouring water or and other thing down your carb is probably not a good thing, but I have changed a thousand blown headgaskets on a thousand cars in my career and every one of them had the most shiny and brand new looking piston top and combustion chamber from running with the steam in it. All the other cylinders would have carbon in them but not the one with the leak.

Just what I have seen, your results may vary. (but I doubt it!)
08-15-2002 05:54 PM
78 monte I've done the water trick too.Had a 305 w/ 200,000mi on it held the rpms up slowly poured water down it,it stumbled blew a black soot cloud out ran better for a littlr while.Don't think I'd try it on any of my good motors though.
08-15-2002 04:52 PM
COCHEV i know this is a hotrod forum but qjets are the best for offroading too. small primaries and a central float boal make for good off idle throttle response and less stalling at severe angles.
08-15-2002 02:54 PM
dmorris1200 While on the topic of pouring stuff down your carb, I remember way back when I was still in school pouring trans fluid down the carb and smoking out all your neighbors. Anyone else remember doing that. I think if I can still remember it was supposed to clean your valves or something, I just liked the smoke. Used to have to drive the car around the block a few times when done.
08-15-2002 02:41 PM
Mertz Like I said I have never taken one apart after doing the water thing so I'm sure that your experieince has more clout than my speculation. I can say that the truck did run better after I did it but that might not have been due to a reduction in carbon.

As for the Corvair, there is documented proof that it works in this high temperature engine. There are hundreds of Corvair nuts like myself that have done it with great success. They are built to run hot. The concern and warning is alway that if your doing it and you kill the engine you'll never start it again.

Thanks for all the comments. I always learn something here. I looked into water injection and found an interesting site. <a href="" target="_blank"></a> This might work for those on a budget that have detonation problems. Might improve gas milage too.
08-15-2002 02:31 PM
4 Jaw Chuck I hope I don't sound preachy but after seeing hundreds of motors apart including mine I don't think anything can prevent carbon buildup. Your right about water injection working wonders on high compression engines, I have used it myself with excellent results. Guess what, those engines had the same carbon buildup as any other I had built. This leads me to believe that water has no effect on reducing carbon buildup.

If done carefully I don't think it really hurts anything but the potential of causing real harm if you inadvertantly kill the engine with excess water and the cold water hit a hot get the picture. The same goes for those pour in combustion chamber cleaners, I have yet to see one that works better than plain old diesel fuel poured into a cold engine with the plugs out and cranking it with the starter.

Just my opinion.

BTW if you want a clean engine, switch to deposits in the combustion chamber but lots of condensation in the oil. <img src="graemlins/drunk.gif" border="0" alt="[drunk]" />
08-15-2002 11:49 AM
Dave E Shank Hey Mertz; Glad to hear you got the old Quadrajet working. I got mine fine tuned, although it is a little hard starting when cold but I still think it is the best carb for street use. I never heard of putting water down the carb but I have learned a lot on this site about new things. Only thing that bothers me is that you see a post a sometimes never hear from the guy again. I wonder if he didn't do himself in??? Dave E Shank
08-15-2002 11:30 AM
Mertz If spraying water down the carb is bad then why are people installing water injection. I am not talking about dumping a gallon of water down the carb of a hot engine. I am applying a controlled spray of water in more of a heavy mist.

I agree that a cold liguid suddenly applied to a hot metal part like a ring could crack it. Theoretically the water becomes steam as it enters the combustion chamber so it is never really a cold liquid.

4jaw Thanks for the history of the battery on the concrete. I always wonder where these things come from. I remember jar batteries but didn't know they used glass batteries in cars.
08-15-2002 11:12 AM
bullheimer hey, neat trick. 4jaw-if thats an old wives tale how come it seems like every time i pick up a battery that i left on the garage floor it's always dead? i know plastic is an insulator so ?

[ August 16, 2002: Message edited by: bullheimer ]</p>
08-15-2002 11:11 AM
4 Jaw Chuck .......and cracking a ring. This is one of those things that many people do and never get into any trouble out of every 1000 or so crack a ring doing this, pouring any liquid down the carb is an invitation to disaster. Yea I know people have been doing it for years but every engine I've torn down needed bead blasting to remove the carbon from the piston domes, I doubt the water gets very much out. Mostly the black you see coming out of the exhaust pipe is the soot that has accumulated in the muffler, not carbon in the engine. I hate to be a party pooper but......This is like the "don't ever put a battery on concrete" wifes tale that never seems to die. I wouldn't do it - ever. A good hard run on the highway will unfoul the plugs just as efficiently.

In case your wondering where the battery fairy tale came from, they used to make battery cases out of glass and the were much heavier than they are today due to the heavy plates. Ever try to put a 150 pd chunk of thin hollow glass down gently on concrete? It would be kind of like trying to put down a full fish tank.
08-15-2002 10:18 AM
Harlequin Dumping water down the carb while the engine is running is one of the best ways of getting rid of all that nasty carbon...
08-15-2002 09:43 AM
Mertz I have been working on a Corvair for a couple of years and have spent a lot of time on the Corvair forum. This is a standard recommendation for cleaning carbon out of an engine. The idea is that it creates steam in a hot engine that loosens the carbon that then goes out the exhaust. The Corvair runs at about 350 degrees so it is pretty effective in making steam.

I have seen other people recommend this proceedure on "standard" engines as well. I figure give it a try it couldn't hurt. I did this with a tank type sprayer when I first got the truck and it seemed to smooth up the idle right after I did it.

Keep the revs up and spray in the water with a garden sprayer until you have put in about a quart. Take it out for a good hard drive (the fun part) and your done. Someday when I need to pull heads I will try this just before I pull them. Some people recommend putting in a little alchohol.

I'm not sure this is a good idea on computer controled cars. It will probably mess up some sensor.
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