Main bearings

Discussion in 'Engine Performance + Maintenance' started by jeremyz71, Apr 7, 2021.

  1. jeremyz71

    jeremyz71 Newbie

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    I have a 98 vortec 5.7 that I’m wanting to freaking up with new bearings the main are stamped 0.0006 does any one know what bearings I should use as you can’t get those bearings anywhere
     
  2. kennythewelder

    kennythewelder B31-3 (6-G) certified

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    Your engine has to be miked, measured with a micrometer. It takes the rite tools,tooling,and knowledge to rebuild an engine. There are a ton of videos on this on youtube. I work at a machine shop, and we will not touch an automotive engine. It takes to many tools that can only be used for one job. 5000 of an inch is a huge difference and there is no way to see that with your necked eyes.
     
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  3. Supercharged111

    Supercharged111 I'm Awesome

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    If the motor is in otherwise good condition standard bearings will be fine. I did this to my 98. When I asked the same question to my local engine builder he indicated that he preferred to be on the loose end of spec. My oil pressure has not suffered for this one bit and I'm north of 280k now. This was in the 220k range.
     
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  4. Hipster

    Hipster I'm Awesome

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    .0006 was Gm's way of select fitting bearings.

    Without looking at a manual the range on serviceable specs is something like .0015 to .0028 so there's some room. There's +/- bearing so look at everything closely to make sure you're going in the right direction.
     
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  5. Erik the Awful

    Erik the Awful Supporting Member

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    Fixed that for you.

    I build my engines with plastigauge. The motor in my truck has a faint gouge in one of the bores. The latest engine I put together didn't quite clean up with a .030" overbore; there's a tiny bit at the top of the cylinder - above where the rings go - that didn't clean up. I built a 500 Cadillac with a grooved bore, and I used an angle grinder to cut down the valve stems for a big cam. A perfectionist would say this is all garbage, but they get down the road with plenty of alacrity. I've seen "perfectly assembled" motors blow up and I've seen garbage last thousands of miles. Not to say that either is bad, you just have to decide how much time or money you're willing to invest.

    The secret is knowing where you can cheat. If you want a perfectly built engine, mic everything. If you just want something that runs good, plastigauge will ensure your tolerances are "good enough". Use loctite on the fasteners that need it. If you're going big on the camshaft, check your valvetrain clearances and geometry. Know where your block plugs go. Finally, if you fire it up and it's making bad noises, shut it down and investigate. I put a .025" hole in the galley plug behind my timing chain to solve a tapping noise.
     
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  6. Supercharged111

    Supercharged111 I'm Awesome

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    You bring up a good point. I assumed this engine was still in the truck which is why I suggested the send approach. If it's scattered on the stand you should put more love into it.
     
  7. red98

    red98 OBS Enthusiast

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    Liked for using the word "alacrity." Love me some good diction.
     
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  8. jeremyz71

    jeremyz71 Newbie

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    I have the engine out of truck going to check clearance with plastic gauge on the bearings
     
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