This tool works perfectly for surfacing exhaust ports on most horizontally opposed air cooled aircraft engines. Pays for itself when you consider the alternative of having to remove cylinders for resurfacing of exhaust ports. Tool is very well constructed (made in USA) and should last for many years. Ive saved a substantial amount in labor costs just in two uses on both and Continental and Lycoming engines. The tool offers excellent control of material removal during the cutting operation. Definitely would buy again, but like I said, the tool is well constructed and will likely last a long time. Be sure to select the proper application mounting bracket for your particular engine. Price is for tool and set of cutter head inserts. You must add the appropriate bracket.

Fast and does a good job, but at $600, needs some serious improvements. Tightening wheel began slipping immediately - cleaned up the glue and fixed with red Loctite®™- worked perfectly. Difficult to center on port - needs some kind of port plug to help center. Also flexed a little and cuts outside of port more than inside. Fix with single-sided razor blade between tool and adapter along outside edge of junction before tightening screws. TapFree® or similar cutting fluid essential to prevent clogging of cutters. Also a file card to clean them.