Review on 💪 Boost Efficiency with the Proform 66785 Piston Ring Filer Manual by Matt Sirmons

Bought this product to sharpen my piston rings for a heavy duty engine. Very simple product, initially it seemed to work well. Upon closer inspection, I noticed that the cutting disc is not level - it wobbles as it rotates. This wobbling can cause some problems as most piston rings are coated with plasma molybdenum and as the blade oscillates it is constantly pressing the top or bottom of the bezel against the tool and scraping the plasma molybdenum off your rings. The handle is too close to the tool, I have been grinding 4.060" diameter rings and with every rotation you slap your hand holding the ring in place. creates an edge on the outside and on the top or bottom of the ring depending on how you place the ring on the deck. Plasma molybdenum on the outside of the ring Pretty bad design overall.