Pontiac Repair: 2.4 head, valve piston, clearance issues

Question
I have a 2.4L head that was milled .030". Will I have valve & piston clearance issues?

Answer
Hi Patrick:

Good question: And I don't have a good answer for you I do know on that engine that the piston doe come all the way up to the deck of the block. The engine is an interferance engine as well meaning if the timing were to jump there is not any clearance between the valves and the piston. My job is just to fix em not to machine the parts. I guess the machine shop would be the place to ask. My gut feeling is no it will not cause a clearance issue but You more than likely will have an issue with spark knock if you use cheap fuel by milling the head you are increasing the compression ratio. If if is not a clearance issue you may have to run 89 or 91 octane fule in this engine especially if the engine do not have an EGR valve. Sorry I couldn't be of more help then that. Good luck. If you get a definitive answer send me an e-mail back just for my own knowledge.