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Has anyone ever heard of using water to clean the carbon off the exhaust valves, By trickling water down the carburetor while the engine is running . I read this on another forum and was wondering if any here ever tried it ?

Sal

Never heard of it, doesn't sound right to me. The only time I've heard of water injection was in some WW2 aircraft that used that at high altitude. The water apparently supplied O2 to the engine that the thin air couldn't.

I do not suggest trying this, I'm only going to mention what I have seen done on flat head engines when I was a young'n. Rotate engine to almost TDC of the firing stroke. Shove as much newspaper as you can down the spark plug hole. Lite the paper with a match and immediately shove a burning torch into the hole blowing pure O2 only. When the smoke stops blowing out of the plug hole you now have a de-coked piston top, chamber and valve faces. Another safer way is to use Seafoam as I have done for over 40 years on coked up 2 cycle outboards.

In the mid seventy's a Cadillac dealer that I worked at installed water spray systems on cars for customers to help fuel mileage,they had a 1/16th hose with a small orifice/jet in line and it teed into the egr suction line at the base of the carb and that was how water was feed from the reservoir mounted on the inner fender. The theory was that the water in a fine mist added density to the combustion chamber and added horse power and helped fuel mileage. In the early eighty's I replaced head gaskets in one of those engines (coolant was leaking)and to my surprise the combustion chambers were completely void of carbon also the valves were like new.This engine had about sixty thousand miles on it.
That same system was used in WWII on Pratt & Whitney R2800 radial engines on emergency power when the throttle was pushed through the safety gate wire and the engines made a whole Lotta let's get the fxx? out of here power!. I know this from working on those and was probably used on other engines also.
Through out the years there have been many witch's brew and top engine cleaner made by different company's to clean carbon but I have never since seen the results that were given by that water spray on the Cadillac. That car went on to run another 125k that I know of with out other problems. So what I am saying that I would not be afraid to run a system like that again as long as it is not over done.

hb

The Big Radials using ADI (Anti-Detonate Injection) included many types both fighters and heavies. It was used for added power on takeoff routinely to get off with heavier loads. These ADI systems mixed the water with methanol 50/50. I can still remember parking T29's and C118's and calling for three trucks (Fuel, Oil, & ADI). The B-52's and KC-135's I worked and flew on used straight de-mineralized water for the same purpose. We also used a mixed liquid solution for cleaning the engines on the ground while they were running.

Thanks guys for the input. I read, that water injectors were used in aircraft for years, But I never heard of using water down the carb. to clean the valves. Wayne I really don't think I'm going to stuff newspapers in a spark plug hole any time soon ..lol I used Sea foam in the past and it works great, I find it really interesting to hear about what was some of the fixes that were done years ago.


Sal

JC Whitney and Warsharsky's ? both sold water injection kits for Cars back then.

I remember that Wes, I also remember the magic tablets they use to sell, that they claimed would fix your leaking valve seals and worn rings. All you would have to do is drop one or two of them in each spark plug hole and add a can of additive to your oil and start the motor. And your motor would be better then new... lol

Sal

A few more thoughts, even though I can't speak to the water injection in engines. Water when flashed off to steam expands and builds pressure. Lastly many oil burner service guys swear by spraying water down a hot boiler to clean off the carbon build up.

way way back when I was a young wrench starting out ,I was shown the by a old hand how to run water down the carb prior to a valve job in order to clean the carbon off the valves and pistons . Bring the rpm up and run a small amount of water down the carb ,don't let it stall out and you know it worked , did it every time after that. When I was working for a GM dealer it was actually called for when a customer came in with a suspected engine knock ,which a lot of times turned out to be a carbon knock . It was quite a common procedure , of course we are talking about some 40 years ago ! I suspect the newer generation never heard of something like that , just ask a young tech to install a set of points and set the dwell and timming by hand without a computer ! . bob k

Bob, how long and how much water would it take to clean the valves? I guess trying this method of valve cleaning on newer vehicles would wreck havoc with the catalytic converters..

Sal

cuz wrote:The Big Radials using ADI (Anti-Detonate Injection) included many types both fighters and heavies. It was used for added power on takeoff routinely to get off with heavier loads. These ADI systems mixed the water with methanol 50/50. I can still remember parking T29's and C118's and calling for three trucks (Fuel, Oil, & ADI). The B-52's and KC-135's I worked and flew on used straight de-mineralized water for the same purpose. We also used a mixed liquid solution for cleaning the engines on the ground while they were running.

Cuz
I was sure there were more Engines that used this system, but I was only exposed to a few of them in the civilian world restoring War Birds and I could not remember the correct name for the system. What I didn't know was that it was used for take off power which makes sense. Thanks for the added info that stuff is very interesting.
hb

My father in law was a master mechanic way before there was ASE testing and was my mentor. I started working with him in his shop in 1976 learning engine work and general mechanics. We did the water down the carb trick alot to clean off the carbon from both the intake and exhaust and intake valves when they were sticking. We would do a compression test and the compression would come up slowly so we knew the valves were sticking and then we would pour water through the carb while keeping up the RPMs. The engine would run smoother after the treatment. We also would pour STP gas treatment down the same way, my how the smoke would roll but it did the trick. I wouldn't try it on the newer vehicles nowadays though.

I guess by some of the responds, The water trick works. I wonder with all the water in today's Gas, is it doing the same thing ?

Sal

I installed several water kits and every one of them claim improved milage. Also used to remove carbon from pistons by removing an intake vacume line and holding the windshield washer hose far enough away to allow a mist to enter the port at about 2000 RPM for 10 to 20 seconds. Worked well to stop that preignition rattle. Only thing I found to clean the valves effectively is a brush. In most cases, the carbon on the exhaust side is minimal unless poor quality fuel was used. Real trouble with build up was on intake side of the intake valves on EGR engines. It would soak up fuel and distort the mixture entering the engine.
Here's A thought. I own a Motorvac carbon clean machine, used to clean fuel systems and combustion cambers all the way to the catalist in injected engines. However, there is also a hook up for carburated units. I know it will clean the exhaust valves. The "detergent" used is available at NAPA, thats where I buy it. It's MV3 for Motorvac units. The other is MV4 used for cleaning the intake like one would use carb cleaner. Make a mixture of 1/2 gallon and MV3, feed it to the carb via gravity after disabling the normal fuel supply. Let it run on fast idle for a half hour at operating temp. Done this on an older tractor by just putting it in the gas tank and it starts easier and no longer fouls the plug.
interestion thing I learned about pulling tractors. The big horsepower modified diesels for competition type. Met this guy who trained techs for Cummins. Says the driver brings the RPM up and watches the gauge for combustion temp. When it gets just right he drop the hammer and puts the water to it. Water? The theroy is, the right temp burns off the oxegen and leaves hydrogen behind to make horsepower. Just might have something to do with those kits from the 80's. FYI, did you know the flames seen at the exhaust tips of a top fuel dragster is the atmosphere burning for the extreme heat, not fuel from the engine.