Hot cams is the first camshaft company to produce its own cores for the dirt bike and ATV market. This means no more core charges or having to send in your camshaft for welding. At hot cams our camshafts for welding. at hot cams our camshafts have been dyno-developed to guarantee improved perfromace. Regardless of what you're riding, your best choice for performance camshafts is always hot cams. No core required (keep your old camshafts), designed to use stock valve springs and rockers, and upgrading to a performance camshaft is the best engine modification for the money.