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Offset crank grinding - May Car Craft 400 chev story

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  • #1

    Offset crank grinding - May Car Craft 400 chev story

    I just read the May CC story on their 400 with some disappointment... they left the pistons anywhere from .062 to .074 in the hole? Holy crap. 40* of timing? Yikes.

    I figure some of the problem was from not having a hell of a lot of deck to work with, stock pistons, slop buildup, whatever, but I kinda freaked. This thing will probably ping like a bitch under any load.

    Right, so enough of me bashing the dirtball build. I've done some pretty dirtball stuff myself, but I'm pretty sure I wouldn't have bothered putting the heads on that one. The question I have here is why not offset grind the crank and deck it at least .010?

    Is there any reason you couldn't offset grind and use 5.7" rods with a 2.0 journal size to get your deck reasonable?

    We've got shops around here that will offset grind a crank for 150.00... 225.00 for Eagle small journal 5.7 rods. It just seems like they left a hell of a lot laying on the table in the name of "budget" but still spent quite a bit on machining. I wasn't impressed with the outcome and almost fell off the stool when I read how much timing it needed.

    Thoughts?
    Flying south, with a flock of bird dogs.
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  • #2
    what was the CR? (I don't have the magazine yet).... however, if it's low enough, a turbo will solve all its problems
    Doing it all wrong since 1966

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    • #3
      Mag is at home, but I think it worked out to 8.36:1 on the .074 in the hole cylinder and they couldn't find a shim gasket for the big bore, so I'm guessing it had at least a .040 gasket. Quench? HAHAHAHA. I wouldn't run a turbo on it either. I guess if you had a [email protected] cam it might make some cylinder pressure, and be on it's face at 4300.

      I think I would have considered an offset grind and 5.7 small journal rods if I were going super cheap. They resized and ground the crank in the story, that could have gone towarks an offset grind and new rods with decent bolts already. I found the 5.7 smalll journal rods for 225.00 with ARP bolts already in them. You'd lose a little bit of stroke, but get decent rods and get the pistons where they needed to be. I don't know what the story is on Chevy cranks though - is there any reason why you couldn't do this?
      Flying south, with a flock of bird dogs.

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      • #4
        offset grind.

        why not get the correct stuff in the first place.

        maybe they know something of stretch or settling in for some of their materials..



        altho, if it is like that, they coulda smacked the same materials off the head and ran it.
        Previously boxer3main
        the death rate and fairy tales cannot kill the nature left behind.

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        • #5
          guess I'll skip that months mag..

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          • #6
            In their defense, there are a million or so disclaimers about the build. It just seemed like a little out of the box thinking and a few more bucks would have picked up a lot. 240 for a crank grind and 100 for resizing the rods would have been almost the same at my local joint as offset grinding and new longer rods with decent bolts... 150/225 respectively. 340 v. 375 ?

            Still, I'm wondering if there is any reason why you couldn't take the pin size down to 2.0 on a 400 crank? I have heard crank hardening blah blah for years from some places and heard it's a myth on others. Anyone wanna speak to that for Chevy cranks? I've been considering doing this with some Ford stuff to close up the deck height rather than cutting the deck since the prices are close to to same and was wondering if there would be problems. In my case the pin is already in good shape, so if I went .030 cut on an offset, it would go .015 higher up the bore and wind up zero deck. Not cutting the deck means I don't have to worry about cutting the intake.

            Or have I picked the wrong week to stop sniffing toluene?
            Flying south, with a flock of bird dogs.

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            • #7
              Originally posted by Beagle View Post
              In their defense, there are a million or so disclaimers about the build. It just seemed like a little out of the box thinking and a few more bucks would have picked up a lot. 240 for a crank grind and 100 for resizing the rods would have been almost the same at my local joint as offset grinding and new longer rods with decent bolts... 150/225 respectively. 340 v. 375 ?

              Still, I'm wondering if there is any reason why you couldn't take the pin size down to 2.0 on a 400 crank? I have heard crank hardening blah blah for years from some places and heard it's a myth on others. Anyone wanna speak to that for Chevy cranks? I've been considering doing this with some Ford stuff to close up the deck height rather than cutting the deck since the prices are close to to same and was wondering if there would be problems. In my case the pin is already in good shape, so if I went .030 cut on an offset, it would go .015 higher up the bore and wind up zero deck. Not cutting the deck means I don't have to worry about cutting the intake.

              Or have I picked the wrong week to stop sniffing toluene?
              in a build like this you could reharden the crank journals.. or just run it..
              or for the same money order a cast or fordged crank already with the 2.0 rods journals
              I'd like to see how bad the flamefront is with the mess they bolted together..

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