Do the job right and stop costly comebacks!! If customers counterbores are worn down and they are hesitant to spend a few extra dollars to do it right, do not warranty the repairs. Too many jobs I do were recent overhauls or have had multiple head gasket repairs, the customer is unhappy and in many cases has taken the engine to different shops to “have it done right”. Counterbore wear is a growing problem. Engines that never had an issue are now failing. I believe the main reason is that horsepower levels are being increased in the same engine design. For example, a John Deere 400 series engine originally was 95-horsepower. Now the same liner sleeve will support 250-horse power or a Cummins L10 originally was a 300-horse power engine and now an ISM with the same liner is an easy 420-horse power. This is a 40% increase!! Also the coolant being used has been changed. I don’t know if this is part of the problem or not but counterbore erosion in a growing concern. For more information, contact Mike Hennes at 320.974.8090.