Product Summary

350 mains Main Journal Style, 3.875" Engine Stroke

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    Key Specs

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

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    Return Policy

    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. 

     

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

    Piston Weight: 433 g. Rod Length: 6.0"
    Bore & Stroke: 4.000 x 3.875
    Ring Style: E

    64 CC  14.2:1  compression ratio

        

    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
    • 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
    • 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

    Application

    • 350 build
      • Piston Diameter = 4.030 Inches (.030" overbore) 
      • Engine Stroke = 3.875 Inches 
      • Computed Engine Displacement (CID) is 395

     

    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 Stroke3.875"
    Connecting Rod Length6.000"
    Connecting Rod MaterialForged 4340 Steel
    Connecting Rod Weight634 grams
    Connecting Rod Bolt Diameter7/16"
    Piston Diameter
    Dome Height0.400"
    Piston Weight433 grams
    Piston Ring StyleE
    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

    Questions & Answers

    4 Questions • 4 Answers

    What do I need to tell my machine shop to do to make this work on a stock 350 block

    by Jeremiahking

    • 9 years ago

    1 answer

    is there any special needed to a stock 060 over 350 block to run this assy thanks

    by elmo

    • 9 years ago

    1 answer

    what is compression ratio with 64cc head and do pistons come 60 over

    by elmo

    • 9 years ago

    1 answer

    can i run this .400 dome piston setup with a stock vortec head?

    by butch1988

    • 11 years ago

    1 answer

    4 of 4 questions shown

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