I used this tool to line bore dozens of cases over the years and it has always done an excellent job for me. In 1980 I purchased a Mainliner, I READ THE INSTRUCTIONS. I started rebuilding VW motors while I was still in high school.
I am 60 years old and have been a machinist/mechanic all my life. I was surprised to see negative postings about the Porta-Tool Mainliner.
