I have a set of AFR 215 heads that have done 4000 miles.Recently at a track day the car developed a bad miss,I thought it might be electrical but after a bit of searching I discovered that an exhaust valve stem had broken At the top groove where the locks fit,lucky the valve didn't drop into the cylinder.I was wondering if this has happened often or is just a one off?

 

Not sure on the AFR valves, but the stock valves have a welded tip. I would either contact AFR or for a better answer shoot a PM to Tony Mamo.

 

Contact AFR....they will get you sorted out

Try to take some good photos and call their Sales Dept. They are still open today if you have the chance

-Tony