Goodson has introduced six new mandrel sizes for its exclusive Hyper-Finish Diamond Valve Guide Sizing System. “These sizes are aimed at today’s cylinder heads with smaller valve guide bores,” says Goodson sales manager, David Monyhan. “The smallest size we offer now is 4.0mm, making them ideal for multi-valve heads.” Other sizes that have been added are 4.5mm, 5.0mm, 5.5mm, 6.0mm and 6.5mm. These are in addition to the original 7.0mm, 5/16”, 11/32” and 3/8” mandrels.
According to Jim Tapp, Goodson Tech Services Manager, the diamond abrasive delivers a fine finish on even the hardest guides. “As guides continue to be made of harder and harder materials, traditional abrasives just can’t cut it anymore,” Tapp said. “We’ve tested the diamond abrasive on a variety of materials and it produced a 25 RA finish in soft guides and between an 8 and a 10 in hardened guides.”