With the OEM valve stem seal, oil will leak if the engine is repeatedly rotated at high speeds over 9,000 rpm. Therefore, we have designed our very own parts to prevent oil leakage in a drag GT-R. The material of this valve stem seal has been changed so that it follows the valve even at 10,000r/min and does not cause oil to drip. It is also included in the head system STEP Pro, but it can also be used alone with the genuine head specification.
