327 Small Valve Heads - NCRS Discussion Boards

327 Small Valve Heads

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Dan White

    327 Small Valve Heads

    My 66 (68 Camaro 327) motor currently has small valve heads (1.72" intake, 1.50" exhaust) which I believe are origional to the engine. Can these heads be taken up to 2.02/1.60 size valves? Or would I be better off with 1.94/1.50? Thanks in advance, Dan
  • Joe L.
    Beyond Control Poster
    • February 1, 1988
    • 43193

    #2
    Re: 327 Small Valve Heads

    Dan-----

    If your cylinder heads are GM casting #3917293 I would not recommend attempting to do anything more than enlarge the intake valve to 1.94". Even that might get you in trouble inasmuch as this casting was never used for any valve size larger than the 1.72/1.50. These cylinder heads were never intended to be a performance-type cylinder head.

    Actually, rather than spending money on these heads, a better plan would be to obtain a better set of heads. 1.94/1.50 heads are very plentiful and the cores are not too expensive. Some of these can be enlarged to 2.02/1.60 without too much trouble, but if you really want to go to the larger valve size, I'd look for a set that was already that size.
    In Appreciation of John Hinckley

    Comment

    • Patrick H.
      Beyond Control Poster
      • December 1, 1989
      • 11608

      #3
      Re: 327 Small Valve Heads

      Joe,

      Or, better yet, if numbers and originality don't entirely make a difference, I'd buy a set of Sportsman S/R cast iron cylinder heads. These will work better than an unworked set of originals and be new to boot. Paint them orange and the vast majority of people will never know.

      I looked at them closely for my 71 350/270 before I decided instead to pull an extra wrong date head out of my spares and install it on the car. I think that these are the most cost-efficient new replacement cast iron head out there without going to the Vortec heads and required manifold swap.

      Of course, I went and found a correct date matched pair of heads for future use, too.....

      Patrick
      Vice-Chairman (West), Michigan Chapter NCRS
      71 "deer modified" coupe
      72 5-Star Bowtie / Duntov coupe. https://www.flickr.com/photos/124695...57649252735124
      2008 coupe
      Available stickers: Engine suffix code, exhaust tips & mufflers, shocks, AIR diverter valve broadcast code.

      Comment

      • Clem Z.
        Expired
        • January 1, 2006
        • 9427

        #4
        Re: 327 Small Valve Heads

        any SB head you install bigger intake valve you must unshroud the chamber wall next to the valve. check a 2.02 head to see a example.

        Comment

        • John H.
          Beyond Control Poster
          • December 1, 1997
          • 16513

          #5
          Re: 327 Small Valve Heads

          Clem's exactly right - 1.94 heads enlarged to 2.02 will actually flow LESS than stock 1.94 heads unless the chamber is machined to unshroud the intake valve; factory 2.02 heads all had additional machining around the intake valve for just that reason.

          Comment

          Working...

          Debug Information

          Searching...Please wait.
          An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

          Please push the back button and reload the previous window.'
          An unexpected error was returned: 'Your submission could not be processed because the token has expired.

          Please push the back button and reload the previous window.'
          An internal error has occurred and the module cannot be displayed.
          There are no results that meet this criteria.
          Search Result for "|||"