I run NGK R5671A-9 & 8s in my Indy headed race engine. 14 -1 compression. What happens is After a race day when I restart the engine next time out at least the 4 corner plugs are fouled. this has been a constant thing. I think this is all from start up . I run an old 1050 8896 dominator . The car runs and idles great. It will restart after warm up with just cranking the motor no fuel required. Any thoughts, ???