How Cylinder Honing Improves Piston Ring Seating

Piston rings are engine parts that seal the combustion chamber, transfer heat from the piston to the cylinder wall, and help regulate oil consumption.  During normal engine operation, only small amounts of exhaust gases and unburned fuel escape the piston rings and enter the crankcase. If there are gaps between the piston rings and the cylinder walls, however, too much “blow-by” can enter the crankcase and overwhelm its ventilation system. The results range from power loss to engine damage.

“The piston ring is sort of the poor stepchild of the high-performance engine,” explains Keith Jones of Total Seal, a Phoenix-based manufacturer of piston ring sets for street and racing engines. “They get blamed for just about everything.” Without the proper fit between the piston ring and the cylinder bore, however, compression blow-by and oil leakage can sideline the kinds of car used in IRL, NASCAR, and World of Outlaws events.

High-Performance Surface Preparation 
As an article in the October 2014 issue of Performance and Hotrod Business magazine explains, Flex-Hone® tools from Brush Research Manufacturing (BRM) can help increase piston ring performance. In “Rings True”, part of the publication’s Precision Engine section, automotive writer Ed Sullivan describes how BRM’s flexible hones “allow for the fine-tuning of cylinder bores”, even in engine blocks made of harder metals that can make piston ring break-in challenging.

BRM Flex-Hone® tools feature abrasive globules that are permanently laminated to flexible nylon filaments, and a sturdy metal stem that mounts in handheld power tools or CNC machinery. Self-centering, self-aligning to the bore, and self-compensating for wear, flexible cylinder hones are ideal for deglazing the walls of cylinders that are not out-of-round, and for improving the surface finish of bores that have been honed to size already.

Flexible honing tools aren’t designed for heavy-duty material removal, however, nor should they be used for initial honing, cylinder resizing, or geometry correction (i.e., out-of-round bores). Instead, use BRM Flex-Hone® tools to impart a plateau finish that optimizes engine lubrication for reduced friction and wear. The crosshatching that flexible honing imparts provides a uniform series of grooves for excellent oil retention, and a superior surface finish that supports piston ring seating and sealing.

Engine Hones and Cylinder Wall Surface Finishing 
BRM’s engine hones are available in 11 different abrasive types and 8 grit sizes. The Flex-Hone® Resource Guide explains how to select and use ball hones, as Flex-Hone® tools are also known. Industry experts such as Keith Jones of Total Seal also provide insights. As Jones told Performance and Hotrod Business magazine, “We recommend this type of hone because it works very well, is easy to use with a hand-held drill motor, and is really foolproof for someone who is not an experienced machinist.”

Michael Miller, BRM’s Vice President of Global Sales, adds that Total Seal “does its homework” when it comes to choosing specific Flex-Hone® tools. The levigated alumina super-fine abrasive that the engine parts maker recommends “works best for their piston rings in harder engine block materials.” Members of the automotive aftermarket and performance racing industries are encouraged to contact BRM with questions about flexible cylinder honing. “We provide this type of support all the time”, Miller explains.

BRM Gets Ready to Hit the Road  
Do your tradeshow plans include a visit to the Automotive Aftermarket Products Expo (AAPEX) in Las Vegas, Nevada next month? From November 3 to 6, BRM will be at APAEX 2014 in Booth #1152 at the Sands Expo. Then in December, BRM’s technical team will visit the Performance Racing Industry (PRI) show in Indianapolis, Indiana. From December 11 to 13, look for Brush Research at PRI 2014 in Booths #5511 and #5513.