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HKS COMPLETE ENGINES

COMPLETE ENGINE

Top-of-the-line STEP Pro+ added to COMPLETE ENGINE VR4.3L

・Focused Driving Situations: Street
・Maximum Torque: ～1900N・m

* Maximum torque is a value calculated based on our in-house test data, we do not ensure that the product can be used without failure.
*Please note that the figure of torque is fluctuated depends on the condition such as vehicle spec, track condition, driving situation or the distance of driving.

For the COMPLETE ENGINE VR4.3 STEP Pro + that is capable for even higher torque, a special I-beam con rod was developed that has a higher buckling strength than the H-beam con rod. In addition, specially designed crankshaft to further increase torsional rigidity. The area of the dangerous cross-section is enlarged by larger pin diameter, and the asymmetrical design of the critical section between pins #5 and #6, where the stress is highest, is thickened only. This minimizes the increase in weight and optimizes the balance ratio by reviewing the counterweight to match the increased weight of the pin section.

Features

STEP Pro+

  • In addition to STEP Pro crank made of high-end racing grade nitriding steel, STEP Pro+ crank is treated with ion plasma to increase surface strength and toughness required of high cycle performance crankshaft.
  • Enlarged crankpin to D57, and inside corner radius to 3.5 for improved torsional strength.
  • New billet I-beam connecting rod for SETP Pro + made from a single piece of flat forged steel has 26% higher buckling strength.
  • 10mm extension in the front of crankshaft to prevent crank pulley fretting
  • Double layer coated piston is specially designed for Pro + effective for sliding under high loads and rotation.
  • Special 3D-Printed oil jet to fit the I-Beam connecting rod.

HKS Complete engine series

  • HKS original oversize main stud bolts
  • #2 and #3 main journal made of Chrome Molybdenum for improved durability
  • Line boring to ensure the roundness of main journal.
  • Main and connecting rod bearings were selected after numerous rigorous tests
  • High thermal conductivity beryllium-free copper valve seats and phosphor bronze valve guides
  • HKS metal head gaskets and extra-strong head studs for improved sealing
  • HKS high lift camshafts for improved performance in high rpm

Note: HKS recommends using HKS Racing Pro 10W50 engine oil.

Connecting Rods

New billet I-Beam connecting rods for STEP Pro + improved buckling strength by 26%.
H-beam connecting rod is lightweight, tensile and buckling strength are excellently balanced. However, looking only at buckling strength, the side walls where stress is high are thinner which could be a fracture origin at high torque. (red part)
Thick side I-beam connecting rod for STEP Pro+ was developed to improve buckling strength significantly. Stress will not concentrate on one area benefit from the new lightweight design. (red part)
Big end is also developed to distribute the surface pressure of connecting rod bearing.

  STEP3 /
STEP Pro		 STEP Pro+
Weidht 720g 752g
Torque
Capavility		 150kgf.m
(approx.)		 190kgf.m
(approx.)

  • STEP3/STEP Pro
    H-Beam Connecting Rod

  • STEP Pro+
    I-Beam Connecting Rod

  • STEP Pro+
    I-Beam Connecting Rod

  • Special 3D-Printed oil jet to fit the I-Beam connecting rod

  • Pistons

    STEP Pro+ double-layer coated lightweight billet piston made from highly heat resistant A2618 alloy.
    (only for STPE pro +)

  • Port and Polish Heads

    Combustion chamber and in/ex ports have been mirror finished by HKS's one of the most experienced engine builders.

  • Connecting Rod Bearing

    Bearing for billet I-beam connecting rod
    (D57, only for STEP Pro+)

  • Crankshaft

    Crank pin diameter and inside corner radius are enlarged to increase torsional rigidity.
    (only for STEP Pro+)

  • Main Journal

    Extra-strong bearing caps for #2 and #3 made of Chrome Molybdenum, and line boring for improved accuracy (STEP Pro & STEP Pro+)

  • Crank Pulley

    Original VR43 crank damper
    (co-developed with ATI)

  • Exclusive Emblem

    DLC coating emblem exclusively for Pro+

  • Original Crankshaft

    Asymmetric crankshaft designed to increase strength and decrease inertial weight at the same time

Specifications

  HKS 4.3L KIT STOCK
Bore 95.5mm 95.5mm
Stroke 99.0mm 88.4mm
Comp. ratio (t=0.8) 8.6 9.0
Allowable RPM 7,400rpm 7,000rpm
Displacement 4,255cc 3,799cc

COMPLETE ENGINE VR38DETT 4.3L STEP Pro+

Engine Head Modifications Seat: Beryllium-Free Copper / Guide: Phosphor Bronze
Step removal and polishing around the sheet
Combustion chamber polishing finish
Camshaft HKS IN：270° / LIFT 11mm
HKS EX：278° / LIFT 11mm
Valve Spring HKS Strengthened
Valve Adjusted to seat
Head Gasket HKS Metal Gasket (t=0.8)
Head Bolt ARP Strengthened Stud Bolt
Block Modifications #2 and #3 Chrome Molybdenum Cap
Oversize Main bearing thread
Enlarged ladder cap hole
Journal oil hole line boring
Honing
Main Bolt HKS M12 Stud Bolt (625+)
Piston HKS billet (Double-layered molybdenum coating)
Connecting Rod STEP Pro+ billet I-Beam
Oil Jets STEP Pro+ 3D-Printed
Crankshaft STEP Pro+ HKS billet (nitride steel & ion plasma heat treatment D57 crankpin enlarged)
Main Bearing ACL
Connecting Rod Bearing ACL (width adjusted）
Crank Pulley Original VR43 Damper
Cover Baking finish
Spark Plug HKS M50HL
HKS COMPLETE ENGINE

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