Say good bye to your spark plugs as the cylinder pressure punches them through your bonnet along with the alluminum holding them in a genuine 630bhp zetec will do this.

A customers 530bhp engine we were mapping did this on the dyno, we were seeing 570 from pauls and are not holding too much confidence of it being reliable. But have done everythg possible to try.

Someone needs to recast these heads before seeing reliable and genuine BIG bhp