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Studebaker V8 head nominal dimension check

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  • Studebaker V8 head nominal dimension check

    Greetings, SDCers,

    We are getting several sets of Studebaker V8 heads together to do a small production run of performance heads. I always check to see how much, if any the head has previously been milled. This is checked by measuring the nominal dimension from rocker cover rail to head deck, which IIRC, is 3.5625". The nominal dimension from the head bolt boss to the head deck is 2.875"

    Today, I pulled out a set of '63 R1 original, never milled 570 heads, miked the first one and yes, 3.560". For the past fifty years, I've only checked one end of each head. Studebaker pride caused me to assume they made it right the first time. For whatever reason today, unfortunately, I checked both ends. One head was .010" different end to end and the other was .007" different.

    When we mill heads, we level fore-and-aft and side-to-side off the existing factory deck with a Starrett machinist's level, so we know we end up parallel to where we started. I checked one set we had done some time back. They vary from .005" to .007" end to end, so those were off from the factory, as well.

    Just for shirts and giggles, if any of you have any known-original heads lying around, put a caliper or micrometer on them and let us know what you find. I measured mine at the outside end of each rocker rail.

    Now, I'm going to CC the combustion chambers to determine if this difference in end-to-end thickness measurement translates to any real difference in combustion chamber volume. It may not make any difference at all, but when we try to control all our machining dimensions to .0005", it does disappoint one that Studebaker apparently didn't give us a fixed reference point from which to work.

    Studebaker always made much of their fully machined combustion chambers, so anyone have any idea from a blueprint or any other source whether the factory used the rocker rail, the head deck or the head bolt bosses as a reference point when machining the combustion chambers?

    thnx, jack vines

  • #2
    Wow, it looks like we need a Studebaker Foundry/Machine Shop Dept. Tech to help us out here! I wonder if any are still on the top side of the Planet?
    Second Generation Stude Driver,
    Proud '54 Starliner Owner
    SDC Member Since 1967


    • #3
      Hey Jack -

      Yea, I've seen that too.

      But to be fair, I've also seen it in the rest (GM, Ford Chrysler) of the factory heads.

      It seems to vary. I can port 3 or 4 sets of heads for people, and see just a coupla thousands...then for some reason, I'll see two sets, like you say are basically full height heads that are .007"-.009" end to end difference.
      I don't pay it much mind, too easy to correct during my normal port work..!

      And absolutly, don't try to correct chamber sizes till after deck milling.
      Though I haven't cc'd chambers before hand, since I do a ton of work in the chamber (you've seen it), I know there's gonna be a little additional work.