Cleaning out the pipes? Egr, Intake and exhaust how to remove carbon?

[hey_allen]

On the aircraft that I work on, we have specific instructions that Simple Green is but one of the cleaning agents that can cause issues with certain metal alloys.

There is time lapse video in part of the instruction, showing a cleaner being sprayed and then rubbed into the metal sample suspended in a tension rig. I'm not sure what time span it covers, but the thing snaps with nothing else done to it.

In the cleaning area here, they do use some cleaner, but from what I can tell, it's not simple green, just due to the smell. Simple Green is somewhat distinctive in that regard.

[UberGeek]

Grease has always been the bane of automotive mechanics and diesel cars make things far worse. Adenauer made an excellent point about the use of oven cleaner that deserves to be expanded.

The bulk of business done by our shop was engine and transmission rebuilding, requiring enormous amounts of time to be spent on thorough degreasing and cleaning of external and internal components. Both the time required and cost of cleaning products and equipment was huge and never fun. After years of experimentation "caustic soda" or sodium hydroxide (NaOH) was found to be the best kept secret for numerous cleaning operations with the added benefit of being water soluable vs those such as Gunk or Kerosene which are petroleum based. This is the active ingredient in "Easy Off", "Draino", dishwasher compounds, and virtually all cleaning products including common soaps. Once the nature of this powerful alkaline is understood, the mysteries of cleaning will be revealed. Without going overboard, there are some very important points to consider as follows:

CONCENTRATION and HEAT are absolutely the most important factors when using any product containing NaOH. On the extreme end of the spectrum I designed and used a caustic soda tank where pure crystal flake was diluted and raised to about 180 degrees. This solution could quickly strip grease, oils, dirt, and paint and leave metal spotlessly clean. It was also a dangerous operation for the inexperienced, particularly if aluminum or zinc were added by mistake, creating a violent reaction. To this day I always keep a jug of 50% concentrate for dilution. This can be commonly and inexpensively purchased as generic "liquid drain cleaner" where it can be diluted X4 for heavy duty degreasing of engines or garage floors or X8 or more for brake and mag wheel cleaner. It can be brushed or sprayed using a HD plastic spray bottle and rinsed off after several minutes with cold water. Temperature will make a dramatic difference on the effectiveness of cleaning, especially when dealing with baked on residues and carbon deposits such as those found on exhaust valves. A hot water rinse or the use of a brush, particularly when applying more solution can speed up the process but safety (see below) MUST BE carefully followed.

SAFETY - This is a very powerful base and like strong acids, especially in high concentrations, it should NEVER be used in a careless way. Safety goggles and rubber gloves are a must and caution should always be exercised when spraying or brushing since the airborne particles can burn or irritate eyes and other sensitive tissues. On the other hand, unlike solvent based chemicals, the byproducts are not toxic.

DRAWBACKS AND BENEFITS - NaOH, from concentrate down to popular diluted products such as mag wheel cleaners and soap concentrates will always attack or dull aluminum and paint. This might not be a problem on engine compartments or suspensions but in higher concentrations can leave streaks or spots on certain paint finishes. The streaks found on mag wheels are often the result of these products on clear coats. If it's really important, aluminum brightener (an acid) can be used afterwards on raw metal.
If used correctly and responsibly, this widely used alkaline has many benefits including saving huge amounts of time and money spent on fancy "salad dressing" derivatives. When applied to grease it compares to the classic chemical reaction NaOH + Lard = Soap. It has many virtues over petrol based cleaners without the oily and environmentally unfriendly byproducts like the slick ugly films deposited under the car, down the driveway, and eventually somewhere downstream. It is also far better for use on rubber, plastics, and brake system parts and provides an ideal surface prior to painting. Lastly, want to know a dirty little secret from a die hard gearhead? On special occasions I have been known to wash my hands with a dilute solution of this stuff. It burns like hell on open cuts and can dissolve the skin a bit, but using only a toothbrush there is no product known to mankind that will clean that hateful grime that spells dirtball to most humans. Just remember to apply some hand creme afterwards and when you raise a glass of wine to toast, don't tell a soul where you heard this.

I hope the forum will find this helpful and if it's not too politically incorrect... I might be encouraged to reveal other dirty little secrets, such as how to sneak a transmission into the dishwasher for a quick power cleaning while the wife's away and not get caught.

[Racekar]

If you want too smooth out the inside of your manifold you can get it Extruda honed. They flow a abrasive oatmeal like paste through it under pressure. Great for intracate manifolds that have long passages. My Contour SVT had it done at the factory, I dont think it would help a diesel out very much since most are turbocharged and it works best to increase airflow in naturaly aspirated engines. Now that alot of engines use plastic manifolds, they already have smooth inner pasages.