This 2.5L BC stroker kit for the Mitsubishi Evo X 4B11T engine platform incorporates a 98mm stroke crank. Depending on bore size that you decide, the BC kit will take you up to a 2.5L with a sleeved 90mm bore. The kit utilizes premium steel billet connecting rods with ARP2000 fastener bolts. As usual, each BC kit features custom CP pistons, steel alloy wrist pins, full ring pack and locks.
Vehicle Fitment:
2008-2015 Mitsubishi Lancer Evolution X
(4B11T CZ4A Evo X GSR and MR models)
Purchase Includes:
4340 billet crank – 98mm stroke
I-Beam rods (5.659 c-to-c)
ARP2000 Rod Bolts
Custom pistons (choice of bore/compression).
Wrist Pins, Full Ring Pack, and Locks
| Part Number: | Description: | Crank: | Rod: | Piston: |
| BC0137 | 2.5L 4B11T | BC5139 – 98mm | BC6137 – 5.659″ | BC7139 – Custom |
Notes:
ACL Race bearings available separately.
Feautres:
• BC 4340 steel billet crankshaft (98mm stroke).
• BC Pro Series connecting rods.
• CP or JE aluminum forged pistons (any bore size, any compression ratio).
• 5100 Series carbon steel alloy wrist pins. 9310 Series pin upgrade avail.
• Ductile iron plasma top rings, tapered second ring, low tension oil rings.
• Fully system balanced and ready to install. (50% deposit required)
About BC Crankshafts:
BC crankshafts are crafted from premium aerospace-grade 4340 steel billet. They are CNC machined on advanced 5-axis Mazak Integrex 300-IV CNC machines to precise tolerances of .0001″. Each crankshaft boasts large radius journals for enhanced rigidity, ideal for high horsepower, high boost, and high RPM applications. The gun-drilled, CNC ground oil holes feature a smooth surface for optimal oiling, with tear-dropped oil scoops and cross-drilled main feeding holes. These cranks are stress-relieved, shot peened, magnaflux inspected, and nitrided for ultimate performance. Fully profiled counterweights are designed to reduce windage in the crankcase, improving RPM potential.
About BC Connecting Rods:
BC connecting rods are CNC machined from aerospace-grade 4340 steel billet and are available in either the European-influenced H-beam or traditional I-beam design, depending on the application. Each rod features a deep, double-ribbed cap that maintains the big end housing bore’s integrity at high RPMs, ensuring uniform bearing crush for optimal oil supply and load capacity. H-beam rods have a deep radial groove pin bushing and oil holes at 5 and 7 o’clock for critical wrist pin lubrication, while I-beam rods have an oil hole at the 12 o’clock position for stability under high boost. Choose between ARP2000 fasteners (rated to 210,000 psi) or ARP’s Custom Age 625+ fasteners (rated to 280,000 psi).
Piston Options:
Choose from top piston brands CP or JE, available in any bore size and compression ratio. Both brands produce custom BC stroker pistons from 2618 T6 high tensile strength forged aluminum. These pistons are designed for strength and minimum weight using computer technology. Each piston is CNC machined for optimal accuracy and superior grain flow. 3D modeling and rigorous Finite Element Analysis ensure the pistons are the strongest and lightest for your application. Custom pistons feature tighter clearances, less noise, better ring seal, and enhanced durability. Standard features include pin fit, carbon steel wrist pins, and either spiral locks or rail supports, with options for upgraded 9310 alloy wrist pins, lateral gas ports, skirt and top coatings, and lightweight design.
