ENGINE BLOCK COMPONENTS


【SHORT BLOCK VR38 4.3L STEP Pro+】
VR4.3L STEP Pro + short block is strengthened for stages that require even higher torque
Concept
Capable for high torque, the VR43 STEP Pro+, contains special designed I-beam con-rods which have a high buckling strength compared to the H-beam con-rods. In addition to the specifically designed crankshaft and to further enhance the torsional rigidity. The pin diameter have been enlarged, and by adopted an asymmetrical design, the cross sections between pins #5 and #6, where stress is the highest, have been reinforced.
In response to the increased weight of the pin section, the counterweight was redesigned to improve the balance ratio.
Features
- As with the STEP Pro, the material for the crank is made of high-end racing grade nitriding steel. Exclusively for the STEP Pro +, the crank is treated with ion nitriding, which increases surface strength and toughness that are required of high cycle performance crankshafts.
- By increasing the inside corner radius to 3.5 and enlarging the crankpin to D57, the structural torsional strength is improved.
- The newly developed, billet I-beam con-rods improves bucking strength by 26%.
- The front end of the crankshaft is extended 10mm to prevent crank pulley fretting.
- Designed specifically for the STEP Pro+, the pistons are coated with a special double layer coating, which is effective for both high-load and high-speed sliding.
- HKS original oversize main stud bolts are used
- Chrome Molybdenum is used to create the #2 and #3 journals to increase durability.
- Line boring process is done to ensure the roundness of the main journal
- The main bearing and connecting rod bearing were selected after numerous tests.
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Crank pin diameter and inside corner radius are enlarged to increase torsional rigidity.
(Only available for STEP Pro+) -
Newly developed Billet I-Beam connecting rods that improves buckling strength by 26%.
(Only available for STEP Pro+) -
Double-layer coated lightweight billet piston made from highly hear resistant A2618 alloy (Only available for STEP Pro+).
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Special 3D-Printed oil jets to match the I-Beam connecting rods
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Extra-strong bearing caps for #2 and #3. Made of Chrome Molybdenum, and line boring for improved accuracy.
Specifications
HKS 4.3L | 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 |
SHORT BLOCK VR38 4.3L STEP Pro+
Block Modifications | #2 and #3 Chrome Molybdenum Cap |
---|---|
Relief of crank interference parts | |
Large Main Bearing Screw | |
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 heat treatment, D57 crankpin enlarged, enlarged R fillet, extended damper mounting area) |
Main Bearing | ACL |
Connecting Rod Bearing | ACL (Width Adjusted) |
Crank Pulley | Original VR43 Damper |