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  • #61
    JT I will say this much --- the newer three piece steel head gaskets are finicky from the start (with their allowance specs) but I think because their not "spongy" they don't allow a head to wander all that much in a "meltdown"

    it's actually very surprising to me, I mean were talking in a few cases enough heat to melt a plastic timing belt cover, and the head will only be out something like a couple thou,

    in fact I really only remember having to go beyond .002" very few times and it was only for an extra thou or so, this is great news for engines with overhead camshafts that have to maintain all of it's main bearing running surfaces in alignment --- many an engine rebuild has gone bad for people who think all they have to do is get a head flat again then seize up their cam(s) first trip around the block...

    anyhoo, it's pretty much a one pass skin cut - heads are nasty for interrupted cut patterns but if the tool is sharp and your DOC is nil you don't even pick up a pattern...

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    • #62
      Makes me wonder what kind of gaskets they're selling nowdays for older designs, such as the Continental F-163 engine. I see these getting rebuilt all the time (Lincoln welder engines). I think that if your block moves around enough to screw up a gasket, then you have a poor design. Not enough meat in between the bores nowdays. And yes, most everything I have ever done, has a spec for surface finish to help retain the gasket, its a lot rougher than many would think. (Older Chevy/AMC sixes and V8's)

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      • #63
        It's a good point about not getting too carried away with your finish - I try to mimic what the factories doing with sometimes taking things one step further with engines I know have issues in certain areas, a little piece of 800 grit or coarse scotch bright sometimes and putting strategically placed "holding area's" not really removing any material just changing the grain a little, ditto on the block...

        any head gasket replacement is a fair size job - I don't like doing stuff twice...

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        • #64
          Originally posted by A.K. Boomer View Post
          It's a good point about not getting too carried away with your finish - I try to mimic what the factories doing with sometimes taking things one step further with engines I know have issues in certain areas, a little piece of 800 grit or coarse scotch bright sometimes and putting strategically placed "holding area's" not really removing any material just changing the grain a little, ditto on the block...

          any head gasket replacement is a fair size job - I don't like doing stuff twice...
          I once watched a guy on another forum rebuild a 1936 welder with a Waukesha engine, he was actually able to cross reference new gaskets for it from Fel-Pro. What really amazed me tho, what the condition of the original block and head surfaces: it was very obvious they had been planed with a shaper! And I thought how that pattern of cutting marks had helped retain the gasket.

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          • #65
            Originally posted by nickel-city-fab View Post

            I once watched a guy on another forum rebuild a 1936 welder with a Waukesha engine, he was actually able to cross reference new gaskets for it from Fel-Pro. What really amazed me tho, what the condition of the original block and head surfaces: it was very obvious they had been planed with a shaper! And I thought how that pattern of cutting marks had helped retain the gasket.
            If an engine company was serious about production,
            most blocks and heads would be flat broached.
            More common than you might realize.

            -Doozer
            DZER

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            • #66
              Originally posted by Doozer View Post

              If an engine company was serious about production,
              most blocks and heads would be flat broached.
              More common than you might realize.

              -Doozer
              I've heard from insiders that this is how GM currently creates the cylinders in their engines. Basically they broach them all in one go. The only purpose for honing is to create just enough surface to break in the rings and retain some oil. Flat surfaces such as the bearing parting surfaces and oil pan/cover rails are likewise flat broached. I get this info first hand from a tour of the Tonawanda engine plant.
              Last edited by nickel-city-fab; 01-17-2020, 05:55 PM.

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