GM 3.8 litre v6 specifications

Discussion in 'Gas Engines' started by ozpolly, Jul 12, 2011.

  1. ozpolly
    Joined: Jul 2011
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    ozpolly New Member

    I am looking at fitting a GM 3.8 litre v6 to a 15' boat i am designing. But i need to know some important specifications .

    The distance of the underside of the sump to the engine mounts?

    From the engine mounts to the top of the engine?

    The overall length of the engine?

    From the centre line of the crankshaft, how low is it from the engine mounts?

    And the overall width and length.

    if anyone can help me with any of these questions it would be a big help..
    cheers
     
  2. whitepointer23

    whitepointer23 Previous Member

    hello ozpoly, why don't you go to the nearest wreckers and get your measurements off an engine, i assume you will be marinising a commodore engine, you can also buy a cheap haynes manual for the specs.
     
  3. Frosty

    Frosty Previous Member

    Im sure it would be a great help for a job like that but these guys here are like you and me, no one will be able to answer those questions.

    These are the problems you come up to on a job like that.
     
  4. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    its all in the OEM drawings of a Mercruiser should your engine be using the same sump and mounts
    Every dealer should have them or certainly get a drawing
    or www.gmpowertrain.com and send an email
     
  5. whitepointer23

    whitepointer23 Previous Member

    he is using a 3.8 holden v6, different to the chev mercruiser 4.3.
     
  6. judgegage
    Joined: Jun 2011
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    judgegage Junior Member

    WOW...Holden...You Aussies with your Road Warrior jokes...JK.

    OZ, The dimension are hard to find. I'm with WP23 get the measurements you need from a wrecker (can only imagine how many were made WW). That engine was converted for marine use (used in a lot of FWD cars), look for conversion parts... that should get you close to the dimensions you need on the bottom.

    I say this because you want a rear sump oil pan.
     
  7. powerabout
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    powerabout Senior Member

    oops
    then try www.kmrolco.com
    they sell marinising gear so maybe they have dimensions
    ( thats an Australian built Buick for those foreigners)
     
  8. ozpolly
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    ozpolly New Member

    thanks for the help. kmrolco was very useful
     
  9. whitepointer23

    whitepointer23 Previous Member

    they are an aus engine originally designed from a buick, but the block is different. holden made a new block with both banks in line not offset like buick. imo it is the wrong choice. i would use a hot 4 out of a jap car, you then only need 1 manifold and you have a good choice of performance engines from jap importers.
     
  10. powerabout
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    powerabout Senior Member

    so the conrods have s bends in them so they dont hit each other?
     
  11. triman692003
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    triman692003 Junior Member

  12. DCockey
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    DCockey Senior Member

    The 3.8 / 3800 engine was redesigned several times during it's long production, including the change in bore centers relative to the crankshaft. I'm certain that the Holden design was not unique but shared with north american built engines. There were both transverse (FWD) and longitudinal (RWD) versions of the 3.8 and 3800.
    http://en.wikipedia.org/wiki/Buick_V6_engine
     
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  13. judgegage
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    judgegage Junior Member

    DC, I looked at that Wiki page and was thinking about the 3.8/3800 I have worked on and 2 I've owned, I could not remember any of them having a bank offset. I thought there may have been some confusion with the even fire and odd fire versions of this engine.
     
  14. DCockey
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    DCockey Senior Member

    Even fire vs odd fire is only affected by the crankshaft geometry, not the block. The original Buick V6 was essentially 3/4 of a V8, and the V6 used a crankshaft with shared rod bearing journals, the same as a V8. The rods for opposite cylinders shared a common journal on the crankshaft which resulted in uneven firing intervals. Around 1977 GM changed the crankshaft to one with offset journals so that the firing intervals were even.

    The bore offset in the earlier engines was relatively small, 5 mm or so, and may not have been very noticeable.
     

  15. whitepointer23

    whitepointer23 Previous Member

    you are right, i did a bit of home work and found out our engine is indeed the american engine with some intake mods, sorry for giving out the wrong info, i read it in a car magazine years ago that it was an aus engine. the change in bore centers just happened to be introduced at the time holden started using it.
     
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