Both cast iron cylinder heads and aluminum cylinder heads are difficult to clean whether by hand or with a cleaning system because of the passages and oil galleys in the designs. Cleaning the cylinder heads requires manual labor and can be difficult to accomplish in a high-volume production situation.
The process of cleaning cylinder heads may involve removing years worth of gunk and debris or it might involved cleaning a new head. Whatever scenario you are faced with, you need to ensure you have cleaned the cylinder head thoroughly before you can put it back to work or you’ll be looking at engine failure down the road.
Cleaning Solutions
There is a lot of concern about the typical cleaning products used for cleaning cylinder heads. Aluminum cylinder heads will not tolerate high temperatures so baking the dirt off is not an option. It may work for cast iron cylinder heads but may not be as efficient as other options.
Environmental concerns have prompted many from using VOC solvents because of the toxic effects it can have on humans and because solvents tend to evaporate quickly, making it harder to clean. There are also standards for disposing of the solvent waste to protect the environment.
Another option that is becoming more popular is an aqueous-cleaning system that uses water-based detergents. The Environment Protection Agency reports that aqueous cleaners contain less than 5% of VOCs. They have proven to be effective at cleaning aluminum and cast iron cylinder heads as well as the old solvents did. Plus the cleaning systems offer detergent solutions that will work on both aluminum and cast iron. The key to successfully using aqueous-based cleaning processes is the choice of detergent being used. Cleaning products are made for specific kinds of material such as cast iron and aluminum. There are also general purpose cleaners. Keep in mind that detergents can make all the difference and provide different results on one type of material you will not get on another type of material. If you have to clean aluminum and cast iron cylinder heads regularly, it may be worth the money to invest in separate cleaning systems as one cleaning product does not work effectively on both types of materials.
Some places are using ultrasonic parts washers that can remove dirt and oil effectively with high-frequency vibrations that essentially sends high pressured shock waves along the cylinder head that scrubs away the dirt by pulling it away from the cylinder head. The agitation also works well to loosen the oil and debris from the design cavities.
Thermal cleaning ovens have been used to clean cast iron cylinder heads very effectively. Some prefer the heat tactic because it dissolves the oil and dirt without much manual labor. In addition to the heating process, there must also be a step that involves the blasting of air. When the debris is loosened, the air is used to blast it off the part. The thermal cleaning process produces a very clean finish, making the part look new again. Other types of cleaning systems can not generate this same result for the finish results.
Your cleaning method for aluminum or cast iron cylinder heads will depend on what results you are looking to achieve as well as what your customers are looking for in a finished product. All are viable methods for cleaning cylinder heads and the choice is ultimately based on what works for your needs.