Cylinder head machining

Can someone tell me or show my how to machine out the valve reliefs on then head for a head that is a 308 head?
I'll be machining my head .060, i just need to know how to mill out my head  for the 7X head valves.


  • Ol racerOl racer Posts: 2,574Senior Contributor
    I usually don't modify the combustion chamber for 7x valves unless install a hilift cam, then only fly cut over the Exh valve area slightly
  • supercubsupercub Posts: 149Member
    You may need a rotary table on a Bridgeport and hold the head on a sine plate or angled fixture if the reliefs are angled, as the valves may be?
  • Courtesy ManCourtesy Man Posts: 207Expert Adviser
    I think I would start by placing the head on the block, with a dial indicator on top of the head and a gasket or shim between head and block. Turn engine by hand wrench and see if valves are pushing the head up. If so then you may need to cut reliefs but I am unclear why a rotary table is recommended. Certainly the head needs to be angled correctly and indicated over the valve face - don't know how you would locate over the valve. And as Ol Racer noted you may not need to do this at all.  Gert
  • supercubsupercub Posts: 149Member
    I was a toolmaker for 15 years, I guess that a rotary table and a radiussed end mill would be my first instinct. A CNC... even better. A dremell tool- even worse.
  • HansHans Posts: 185Senior Contributor
    For a quick look. does any one still use childs play clay, just to get an idea of any interference ?
  • blondwookieblondwookie Posts: 239Member
    I like to build performance engines. Building a flat head engine is new to me. I've built high performance small and big block Chevy and and B and RB Chrysler. These are big block engines. All of the input i get to get more power out of my engine will help me a lot. 
  • GlowplugGlowplug Posts: 2,232Expert Adviser
    There is a wealth of information on my website that I have gleaned from experts who have made Hudson engines produce HP. 
    Check the Engine section of my site and read the selections throughly the experience detailed there can not be purchased.
  • BigSkyBigSky Posts: 976Senior Contributor
    Glowplug’s site is a great resource & here is the link to Hudsonator’s 308 engine build on the site:
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