Forged Rods & Pistons Kit – BMW B48

A complete forged bottom-end kit for the BMW B48, pairing 4340 chrome moly H-beam rods with 4032 forged pistons. Together they give a tuned B48 the strength for high boost and high RPM that factory internals can't match, whether you're building a track car or a daily-driven sleeper. ARP 2000 bolts included.

Specifications

What it does

• Handles big power, with 4340 H-beam rods and 4032 pistons that take high boost and cylinder pressure together, rated to 800–1000+ hp.
• Lasts under load, both forged, CNC-machined and shot-peened for fatigue resistance under detonation and knock.
• Runs cooler and smoother, with 4032 pistons that reduce thermal expansion and slap, everything balanced within ±1.5g per set.
• Built around ARP, with precision-machined caps and deep locking grooves that seat genuine ARP bolts for maximum clamping force.

Build quality

Matched forged rods and pistons, precision CNC-machined for true bores and tight clearances and shot-peened for stress relief. Pair with upgraded bearings, head studs and proper cooling for the complete forged bottom end.

Compatibility

Fits all Gen 1 and Gen 2 BMW B48 engines across 1, 2, 3, 4 and 5 Series, X1, X3, X4 and MINI (F- and G-chassis).

Please confirm piston compression height and crown clearance for 20i & 30i, and confirm Gen 1 vs Gen 2 B48 variant before assembly.