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Product Summary

400, 434, 350 mains Main Journal Style

    Key Specs

    MFG. Part #
    Cylinder Bore Size
    Connecting Rod TypeH-Beam
    Piston StyleDome
    Piston MaterialForged Aluminum

    Need To Know

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    Details

    Speedway introduces forged rotating assemblies, with an optional balance job. Includes new 2-pc rear main seal crank, rods and pistons. Cranks are new so they use standard size bearings.

    All Scat 4340 cranks are 2-piece rear main seal, internally balanced and weigh approximately 51-55 lbs.  All balancing is done with our state-of-the-art "hines" balancer by race mechanics with over 30 years of experience!  A kit purchased with the optional balance job will ship in 24-48 hours (must be purchased separately, part # 91510200). These rotating assembly engine rebuild kits may require additional charges for heavy metal.

    If you are going to run this crank in a sprint car motor, you must have the crank flange turned down prior to balancing the crank to allow it to go through the motor plate.

    Chevy 434: 4.125" bore x 4.00" stroke

    NOTE: Piston rings are not included and must be purchased separately. Use Style C rings.

    Item Details

    .180" dome, 460 g.
    Comp. 76cc: 12.7

    C/R 64cc=14.5, 69cc=13.5
    Piston/Pin Weight: 589 g
    Rod Length: 6"     

    Kits feature:

    • Scat 4340 Forged Steel Crankshaft
      • Standard size journals
      • Straight shot and chamfered oil holes
      • Nitride hardened and shot peened
      • Lightening holes in all rod throws
      • Large radius on all journals
    • KB Signature Series Forged Pistons
      • 2618 aluminum alloy construction
      • T-6 heat treated
      • 4.000 " bore pistons available in standard, .030, .040, or .060 sizes
      • 4.125 " bore pistons available in .030 or .040 sizes
    • Speedway 4340 H-beam Connecting Rods
      • Full floating pin in silicon bronze bushing
      • Precision bolt bushings to positively locate cap
      • 6.0 " lengths
      • 634 grams
      • Weight matched set of 8 rods
    • King HP Series Main and Rod Bearings
      • 0.015 " thick top layer for superior macro particle embedability and conformability
      • 40 Vickers hardness to resist overlay migration and extrusion
      • 450°F heat threshold for superior protection against friction and overheating
      • Mains are 3/4 grooved for improved oiling to the rod journals
      • Bi-metal aluminum silicon alloy featuring fine micro-bore finish

    Kits feature:

    • Scat 4340 Forged Steel Crankshaft
      • Standard size journals
      • Straight shot and chamfered oil holes
      • Nitride hardened and shot peened
      • Lightening holes in all rod throws
      • Large radius on all journals
    • KB Signature Series Forged Pistons
      • 2618 aluminum alloy construction
      • T-6 heat treated
      • 4.000 " bore pistons available in standard, .030, .040, or .060 sizes
      • 4.125 " bore pistons available in .030 or .040 sizes
    • Speedway 4340 H-beam Connecting Rods
      • Full floating pin in silicon bronze bushing
      • Precision bolt bushings to positively locate cap
      • 6.0 " lengths
      • 634 grams
      • Weight matched set of 8 rods
    • King HP Series Main and Rod Bearings
      • 0.015 " thick top layer for superior macro particle embedability and conformability
      • 40 Vickers hardness to resist overlay migration and extrusion
      • 450°F heat threshold for superior protection against friction and overheating
      • Mains are 3/4 grooved for improved oiling to the rod journals
      • Bi-metal aluminum silicon alloy featuring fine micro-bore finish

    Specifications

    KEY SPECS
    MFG. Part #
    BrandSpeedway Motors
    Cylinder Bore Size
    Connecting Rod TypeH-Beam
    Piston StyleDome
    Piston MaterialForged Aluminum
    GENERAL
    Main Journal Style350 mains
    Engine Stroke4.000"
    Connecting Rod Length6.000"
    Connecting Rod MaterialForged 4340 Steel
    Connecting Rod Weight634 grams
    Connecting Rod Bolt Diameter7/16"
    Piston Diameter
    Dome Height0.180"
    Piston Weight460 grams
    Piston Ring StyleC
    Crankshaft MaterialForged 4340 Steel
    Rear Main Seal Style2-piece
    Wrist Pin Diameter0.9272"
    Main Journal Diameter2.448"
    Rod Journal Diameter2.10"
    Bearing ConstructionBi-metal
    Bearing UndersizeStandard
    Narrowed BearingYes
    Coated BearingNo
    Sold in QuantityKit