Click and Clack at it again - De-carbonizing an engine.

[roccaas]

This guy puts his Blazer hood first into a Florida pond. No water gets into the cylinders. Mechanic checks everything over, replaces some electrical parts, and the truck runs MUCH smoother than before the half drowning.

Tom and Ray feel that there was enough moisture in the intake manifold to de-carbonize the engine, hence smoother running (who knew??). They admit to introducing water by a vacuum hose (off the carb?) into engines to take out the carbon.

Now there is a machine they can upsell to clean your engine, so they don't do the water thing anymore.

Two questions:

1. How much water, where and how introduced to rid the A of carbon?

2. Does this have anything to do with the thread some 2 years ago on FB about how much smoother a car runs after a rainstorm? (I thought we'd decided on denser air providing better combustion?)

First Carb icing, now de-carbonizing with H2O!

[hardtimes]

Hey roccaas,
Using water to decarbonize an internal combustion engine is nothing new. Of course, you can't run tooo much water and have to know what you're doing. I don't think that running an engine into a cannel is representative of the proper way to do it and/or a good idea.

[J Franklin]

In auto shop we were told to add water as a mist while the car ran and increase mist till is stalled out (don't pour it in). let it sit overnight and don't restert it near the garage door or you will need to clean the door of carbon soot.

Your car will run nice in a rainstorm because the water vapor in the air expands entering the hot cylinder and gives a compression boost.

[hardtimes]

Originally Posted by J Franklin

In auto shop we were told to add water as a mist while the car ran and increase mist till is stalled out (don't pour it in). let it sit overnight and don't restert it near the garage door or you will need to clean the door of carbon soot.

Your car will run nice in a rainstorm because the water vapor in the air expands entering the hot cylinder and gives a compression boost.

X 2....both comments!

[sphanna]

Moist humid air is less dense than dry air. So the density of the atmosphere is less and this robs power from the engine. If the air has water vapor in it, it is already vaporized and will reduce the effective air charge density. So in order to see the effect of increase power, you must inject liquid water into the cylinder. This water charge then instantly turns to steam and increases the compression. It also will remove carbon as this steam cleans the cylinders. That is what I have been taught anyway and confirmed by operating aircraft engines for 50 years.

[Mike V. Florida]

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Originally Posted by sphanna

Moist humid air is less dense than dry air. So the density of the atmosphere is less and this robs power from the engine. If the air has water vapor in it, it is already vaporized and will reduce the effective air charge density. So in order to see the effect of increase power, you must inject liquid water into the cylinder. This water charge then instantly turns to steam and increases the compression. It also will remove carbon as this steam cleans the cylinders. That is what I have been taught anyway and confirmed by operating aircraft engines for 50 years.

Mustangs in WWII used water injection for a power boost.

[Patrick L.]

Its been done for years. Its best to use a spray bottle and not pour it in. Raise the idle speed and start spraying which will steam clean the cylinders, don't let the engine quit. It came back into vogue during the early days of computer controls as these engines would build carbon to the point of knocking. GM even sold pressurized cans of water just for this purpose.