Built To Survive The Stroke Increase Stock KA24DE Cranks Cannot Handle
The Brian Crower BC5218 is a fully counterweighted 4340 billet crankshaft engineered specifically for Nissan KA24DE builds that need more displacement without sacrificing durability at high RPM. Machined from a solid 4340 chromoly billet rather than a cast core, this crankshaft delivers a 96mm stroke with large radius journals and a nitrided finish, giving engine builders a stronger foundation for turbocharged, supercharged, and naturally aspirated KA24DE combinations. Every unit is CNC machined to tight tolerances and fully counterweighted for smoother operation than a stock or reground crank, making it a common upgrade for 240SX, Altima, Frontier, and Xterra builds that are being pushed well past factory power levels.
Key Features
- 4340 Chromoly Billet Construction: Machined from solid billet bar stock, not cast, for significantly higher fatigue strength under boost and high RPM loads
- 96mm Stroke: Increases displacement over the stock 90mm KA24DE crank for more low end torque and additional power potential
- Large Radius Journals: Reduces stress concentration at the fillet area, a common failure point on stock and reground cranks
- Nitrided Surface Treatment: Improves surface hardness and wear resistance on the main and rod journals
- Fully Counterweighted Design: Reduces vibration and improves rotating assembly balance compared to lightweight or partial counterweight designs
- CNC Precision Machining: Machined to Brian Crower’s tight dimensional tolerances for consistent fitment and balance
This Part Fits
| Year Range | Make | Model |
|---|---|---|
| 1991-1998 | Nissan | 240SX |
| 1993-1997 | Nissan | Altima |
| 1998-2004 | Nissan | Frontier |
| 2000-2004 | Nissan | Xterra |
Specifications
| Detail | Value |
|---|---|
| Part Number | BC5218 |
| Material | 4340 Chromoly Billet Steel |
| Stroke | 96mm |
| Rod Journal Diameter | 49.96mm |
| Main Journal Diameter | 59.97mm |
| Journal Radius | Large Radius |
| Surface Treatment | Nitrided |
| Counterweighting | Fully Counterweighted |
| Country of Origin | United States |
| Lead Time | Special order, allow extended production time |
What’s Included
- One (1) Brian Crower BC5218 4340 billet crankshaft, 96mm stroke
About Brian Crower
Brian Crower has manufactured performance camshafts, crankshafts, connecting rods, and valvetrain components in the United States for decades, with a catalog built around Japanese and European engine platforms that see heavy use in road racing, drag racing, and time attack. The BC5218 reflects that same race proven approach applied to the KA24DE platform, giving builders a billet foundation designed to hold up under sustained high RPM and boosted operation.
Related Parts
- ACL Nissan KA24DE Standard Size High Performance Rod Bearing Set
- ACL Nissan KA24DE .25mm Oversized High Performance Rod Bearing Set
- ACL Nissan KA24DE Standard Size High Performance Main Bearing Set
- Clevite Nissan KA24DE Series Main Bearing Set
Frequently Asked Questions
What is the BC5218?
The BC5218 is a Brian Crower 4340 billet crankshaft for the Nissan KA24DE engine, machined with a 96mm stroke, large radius journals, and a nitrided finish for high horsepower street and race builds.
Does this crankshaft increase displacement over the stock KA24DE crank?
Yes. The stock KA24DE crank uses a 90mm stroke, so the 96mm stroke here increases displacement and adds low end torque once the rest of the rotating assembly is matched to it.
Can I reuse my stock rods and pistons with this crankshaft?
Not typically. A stroke increase changes piston travel and compression height requirements, so most builders pair a stroker crank like this with stroker specific rods and pistons rather than reusing stock components.
Does installing this crankshaft require a full engine teardown?
Yes. Crankshaft replacement requires complete disassembly of the engine block along with clearance checks, bearing selection, and a full balance job before reassembly.
Will this crankshaft work with a turbocharged KA24DE build?
Yes. It is commonly used in both turbocharged and naturally aspirated KA24DE builds thanks to its billet construction and large radius journals.
Does this crankshaft come pre-balanced?
No. Like most aftermarket billet cranks, final balancing is performed by the engine builder as part of the complete rotating assembly, since balance depends on the specific rods, pistons, and pins used.
What bearings should I run with it?
Builders typically run high performance rod and main bearing sets sized to the crank’s journal diameters rather than reusing stock KA24DE bearings, which are matched to the factory crank tolerances.
Is machine shop work required before installing this crankshaft?
Yes. Standard practice includes verifying journal clearances, checking block deck height and boring as needed, and confirming rod and piston compatibility before final assembly.
How long does Brian Crower take to produce this part?
This is a special order item, so production and shipping timelines run longer than in stock parts. Confirm current lead time before finalizing a build schedule.
Install Instructions
- Fully disassemble the KA24DE engine block and remove the factory crankshaft, rods, and pistons
- Inspect and machine the block as needed, including boring for new pistons if the rotating assembly is being upgraded alongside this crankshaft
- Select rod and main bearings sized to the crank’s journal diameters and verify clearances with plastigauge or a micrometer
- Install the BC5218 into the block with the selected bearings, torque main caps to spec, and confirm the crank rotates freely
- Assemble rods and pistons matched to the 96mm stroke, checking piston to wall and rod side clearances
- Have the complete rotating assembly balanced before final engine assembly
- Complete reassembly of the KA24DE engine and verify oil pressure and clearances before first startup
