ENGINE BLOCK COMPONENTS

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.

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+

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