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THIS ISSUE: PG 44 >> SEMA Engine
PG 47 >> Profitable Performance
clean cast iron and aluminum parts in the same batch. High temperatures inside a cleaning oven can also loosen the seats and valve guides in aluminum heads. If the seats and guides are being replaced anyway, it’s no big deal and may save you some disassembly time. On the other hand, if the original seats and guides are being reused, and you don’t want them to fall out, thermal cleaning may not be the best option for aluminum heads. The cleaning technique (or combination of methods) you use should leave the heads and block free of dirt, grease, carbon and lime deposits. Residual carbon deposits that are still clinging to combustion chambers or exhaust ports can be brushed or blasted away, but that requires additional manual labor (which should be avoided to minimize your cleaning costs). The cosmetic appearance of the metal doesn’t matter until the final postmachining cleaning has been completed and the block and heads are
PG 50 >> Supply Line
ready to be assembled, painted and/or bagged and returned to the customer. Bagging is highly recommended to keep out dirt while parts are being stored and transported. When final cleaning an engine block, the cylinders should be manually scrubbed with hot soapy water to remove all traces of honing residue from the bore surfaces. Wiping the cylinders with ATF or WD-40 can prevent rust but it won’t remove honing residue. You have to use detergent to loosen, lift and wash away the residue. Dry blasting aluminum with glass beads, aluminum oxide grit or steel shot (stainless works well and lasts a long time but is expensive) can remove discoloration. But this requires an additional cleaning step to make sure no beads, grit or shot are left behind in any of the nooks and crannies of the casting. Masking off the valve guide and cooling jacket openings prior to bead or grit blasting can reduce the risk of media being retained. Another cleaning alternative is to
use a soft blast media such as plastic beads, walnut shells or baking soda to clean both cast iron and aluminum castings. Baking soda has proved to be an effective cleaning media on cast iron and aluminum, and can be used dry or mixed with water to create a cleaning slurry. Adding some aluminum oxide to the mixture can increase its cutting action even more. Baking soda is relatively soft compared to other traditional blast media (only 2.5 on the Mohs hardness scale), and it is inexpensive and is water soluble (making it easy to wash off afterwards). It can scour away carbon, rust and paint, but unlike other media dry soda can only be used once (wet soda can make several passes). When baking soda hits the surface of the metal, it fractures as it knocks loose the surface contaminants. This creates a lot of dust, so the blasting has to be done in a sealed cabinet. By comparison, wet soda blasting is a closed-loop process that eliminates the dust. ■
ARMEX® Baking Soda Blast Media — Discover the Difference Case Study:
Engine Parts Cleaning Application Overview: Clean aluminum cylinder heads without leaving particles behind in critical passageways risking engine failure and increasing warranty issues. Process: ARMEX Maintenance Formula XL at 50-60 psi in contained cabinet system. ARMEX Turbine Formula at 45 psi for heavily burned in carbon. Followed by a water rinse. Results: Achieved a higher level of clean, lowered process time and energy consumption. Reduced labor, no post process detailing required. Eliminated warranty issues due to media lodging. “We’re saving money, time and cutting hazardous waste.”
Feature
APPLICATIONS USE ON: Engine parts, aluminum components, composite materials, and chrome REMOVE: Paint, grease oil, burned in carbon, and corrosion.
BENEFITS – Safe on most surfaces even glass – Rinse residues from surfaces and passageways – Safer for workers and the environment
For further case studies and more information go to
ARMEX.com or call 800-332-5424 ARMEX® and ARM & HAMMER® are registered trademarks of Church & Dwight Company. ISO9002 Circle 43 for more information
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