We advise customers every day on how to choose the right Flex-Hone and have made grit recommendations for Flex-Hones for many years. Based on our experience it is usually a pretty straight forward proposition. In the case of automotive combustion cylinders, 120 grit works for older cast ring sets or where the cylinder has been re-bored and is a little rough. 180 and 240 grits are good choices for general deglazing where the cylinder is not going to be bored or honed. 320 grit is often used in high performance applications with chrome molly rings. I sometimes see the guys running dragsters ask for a 400 grit but they are re-honing after every few runs. So you can imagine my surprise when the phone started ringing off the hook asking for a 4” Ballhone made with Levigated Alumina.
We make the Flex-Hone in 11 abrasive types and 8 grits but this is the first time anybody has asked for Levigated Alumina for their big block Chevy. Levigated Alumina is a special abrasive we use for several industrial applications. Easily identifiable by its white abrasive, it only comes in one grit: extra fine (approximately 1000-1200 grit). I gave them my usual spiel about maybe this being a little too fine but they were adamant. I scratched my head a few times knowing the customer is always right and filed it away for future thought until the phone kept ringing with more requests. Turns out my good friend, Keith Jones, over at Total Seal High Performance Piston Rings had hit on something and he was advising all his customers to call Brush Research to order one. It didn’t take me long to get Keith on the hook for a little education.
Keith told me that Total Seal had developed a new piston ring that profited from the super smooth finish provided by the levigated alumina material. Total Seal had tested it and were really excited by the results. Keith also mentioned that using Levigated Alumina is very effective after the two-step diamond honing process which has become so trendy these days. He explained because the two -step process produces a surface with very little “valley” depth for oil retention, it is important to create a plateau finish with minimal material removal. He found the Flex-Hone with levigated alumnia to be just the trick. This makes a lot of sense after I think about it and I guess you can say this is one old dog that has learned something new.
Written by Mike Miller, BRM
Posts
