unfortunatly it is a greatly possible that you have damaged your valves or pistons. find out if your engine is interferance or non-interferance, if it is a non-interferance then you have nothing to worry about. in a non-interferance motor the pistons have grooves the shape of the valves so that if the valves are wide open and the piston is at TDC they will not touch. you could do a compression test and if the compression is low do a cylinder leakage test. if you need help with the tests let me know. these tests are great for finding the problems without tearing the motor apart only to find out that you didnt need to do so. -keep me posted