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  • One way to build a strong Volvo Red Motor (aka B230)

    Posted by Ken Lanham on August 21st, 2008

    This text is lifted from the my old web page about my 1988 Volvo station wagon. I made some updates and completed the text so it now has pretty complete information needed to assemble a similar shortblock. I’m re-posting it here for so people can find it easier and search for it on google or turbobricks.com website.
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    Shortblock details

    This is how you build a strong long stroke Volvo Red Motor

    Block

    I started with a 1984 B23 block. At the time of assembly, this was considered the strongest foundation to start with. The block is a little heavier than the late blocks due to more iron in some spots, and it also has a forged steel crankshaft that doesn’t come in the later motors. Since then people have proven that the later blocks and cranks are strong enough for just about anything you can throw at them. But I started with the best at the time:

    Block Specs:
    1984 Volvo B23FT
    Bore: 3.800″ (.030″ over)
    Deck Height from crank center to top: 9.125″

    Crankshaft

    Crankshaft
    The backbone of a strong motor is the crankshaft. I started with a B23 forged crank. My machine shop did an offset grind on the rod journals to use Mitsubishi 4G63 connecting rods. The rod journals now hold the mitsu rods with about .010″ side clearance. Much nicer than the Volvo setup which guides the rods from the piston. The crank was heat treated after grinding. In metric measures, I started with an 80mm stroke Volvo crankshaft and ended up with 88.8mm stroke
    Stroke: 3.496″
    Rod Journal dia: 1.771″
    Rod Journal width: 1.130″

    Pistons
    The pistons are custom from Diamond Racing. I specified the dish shape to match the combustion chamber of the 16 valve head. And they fit the Mitsubishi 4G63 rods I am using. The piston to head clearance should be about .040″, just about right for good squish. This was a priority for me, since I’ll be trying to maximize power with this turbo motor running on pump gas. Tight squish motors help keep detonation away. As a curious observation, there are 3.800″ bore pistons for small block Chevy motors with very close compression height. It could be worth looking into if you are trying this type of build on a tight budget.
    Piston Specs:
    Diamond Racing Products Custom Pistons
    Bore: 3.800″
    Compression Height: 1.471″
    Rings: 1.5mm,1.5mm,3.0mm
    Piston Weight: 419g
    Piston to Bore clearance: .006″

    Rods

    The engine uses a set of Scat H-beam connecting rods for a Mitsubishi 6-bolt 4g63. These rods are nice and strong with an ARP 3/8″ cap screw holding the caps on. They also have a small hole drilled in the big end that sprays oil on the pistons. A nice little bonus feature.
    The rod dimensions are:
    Scat Rods for 4G63 Mitsubishi
    Length: 5.906
    B.E. dia: 1.890
    pin bore dia: .827
    Big end width: 1.117
    Small end width: 1.010


    Some pictures of the assembly coming together. The final displacement is roughly 2.65 liters. Enough for some extra low end grunt.

    IMG_2509IMG_2631IMG_3019
      16v_intake2

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