351W .30 over bore = ?

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by Mstng2, May 14, 2004.

  1. Mstng2

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    Hey here one for the engineers out there and High perfomance engine guys/gals! I am going to put the displacement of the engine on the side of my cowl scoop when it's finished. It's a 351W bored .30 over. Does anyone know or can calculate the actual displacement of the engine for me?? I'm guessing around 368 or so but would like to be specific and have custom graphics made for it.
    THanks in advance! :nice:
     
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  2. cobraii351

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    A .030 bored 351 is 357cid.

    Tim
     
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  3. Power Surge

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    A 351 bored .030 over will give you about 5 extra inches. So you'd wind up with a 356. Just for reference, a 302 would go to a 306, and a 460 would go to a 466.
     
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  4. a351Must2

    a351Must2 Windsor II
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    and a 351W bored .060" over will give you 362ci of hot running, thin cylinder wall, overheatin' fun :D
     
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  5. jeffnoel

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    Ditto on the 356.
     
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  6. Blue Thunder

    Blue Thunder Active Member

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    3.5 stroke x 4.030 bore rounds up to 357 cubic inches. (unless you remove all floating points, of course, which is against standard mathematical rules)

    You actually gain more cubic inches from boring a motor with a longer stroke than you do by boring a motor with a shorter stroke, but it's not usually a big difference.

    If you increase the bore of a motor by .030" which has a 2" stroke, you will only gain 3 cubic inches of displacement. While boring a motor by .030" which has a 5" stroke will yield an increase of 7 cubic inches. (rounded up, when applicable)
    Of course, that difference, while remaining proportionately similar, becomes far more apparent(and valuable from a performance perspective) when you further increase overbore:
    2" stroke x +.100" = +11 cubic inches.
    5" stroke x +.100" = +25 cubic inches.

    By the way, why not take a jab at the imports and put 1.9L (x3) on the cowl?
     
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  7. 77sleeper

    77sleeper GO BUCS!
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    AND more compression too :nice:
     
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  8. zwhitr

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    http://www.edelbrock.com/automotive/math.html


    Formula for CID (cubic inch displacement)
    CID = NUMBER OF CYLINDERS x SWEPT VOLUME


    Note: CID = N x 0.7854 x bore x bore x stroke (all in inches)

    Example: What is CID of a V8 with a “30 over”, 4 inch bore and 3.48 inch stroke?

    CID = 8 x 0.7854 x 4.030 x 4.030 x 3.48 = 355 cu. inches


    or you could use Volume = Pi X r(squared) X H




    About Compression Ratio

    Formula for CR
    CR = COMPRESSION RATIO = CYL. VOLUME @ BDC ÷ CYLINDER VOLUME @ TDC


    = 1 + (SWEPT VOLUME ÷ VOL @ TDC)
    = 1+ (0.7854 x BORE x BORE x STROKE) ÷ (CCV + HGV + PDV)
    CCV = Combustion Chamber Volume, in cubic inches

    Note: if volume is given in cc’s then ÷ 16.4 to get cubic inches.

    HGV = Head Gasket Volume, in cubic inches,
    = Head gasket compressed thickness x 0.7854 x bore x bore
    PDV = (Piston Deck Volume) + (Piston Dome Effective Volume)
    = (0.7854 x bore x bore x deck to piston distance) + (volume of piston depressions - volume of piston bumps)

    Example: What is CR of the engine in #9 if heads have 72 cc chamber, head gasket is compressed to 0.040 inch and flat top pistons give 0.025 deck clearance at TDC?

    CCV = 72 ÷ 16.4 = 4.39 cubic inches
    HGV = 0.040 x 0.7854 x 4.030 x 4.030 = 0.51 c.i.
    PDV = 0.025 x 0.7854 x 4.030 x 4.030+ 0- 0 = 0.32 c.i.
    CR = 1+ (0.7854 x 4.030 x 4.030 x 3.48 ÷ (4.39 + 0.51+ 0.32))
    = 1+ (44.39 ÷ 5.22) = 9.5 CR



    http://www.edelbrock.com/automotive/math.html
     
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  9. 77sleeper

    77sleeper GO BUCS!
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    like I said

     
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  10. Johan

    Johan Member

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    You talk like a bowtie boy. That's a bored over 350.

    A 351 has a bore and stroke of 4.000 x 3.500

    CID = 8 x (pi/4) x bore^2 x stroke
    = 8 x 0.7854 x 4.030" x 4.030" x 3.500" = 357 in^3
     
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  11. zwhitr

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    Thems fight'n words. :uzi: :chair:

    Check the link I was cut'n and past'n

    Edelbrock tends to cater to them there chebbies

    on a quiet night you can just sit and here a chevy rust.
     
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  12. Apsychotic

    Apsychotic New Member

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    357

    Hey, in my opinion, the "357C.I." would look the coolest on the cowl anyways. :D :flame:
     
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