400 port and polish ?

1 reply to this topic
  • TuningFork426

Posted March 27, 2007 - 03:19 PM


so heres the thing, I bought a ported and polished 400 head off ebay for my 426. Upon further inspection i found that the intake is really smooth. I looked into it and read smooth is bad. I'm not sure who did the porting/polishing,
how much performance could i lose?

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  • Birdy426

Posted March 27, 2007 - 05:24 PM


I doubt you will lose any performance. The blending and grinding away of casting flash and "flow trips" will improve performance. It looks like there was some reshaping done as well to control intake charge velocity. What "rough" does, and rough is a relative term, is keep the boundry layer flow turbulent, which helps keep the fuel atomized. If you are concerned about it, take the head to a good machine shop and have them glass bead the intake port. You'll be "In like Flynn" and it won't cost you much. (Be sure they mask off the seats, guides, etc first!)


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