BMW N55 Forged Internals — Rods & Pistons Kit
The BMW N55 3.0L inline-6 is one of the most tunable engines BMW has ever produced — found in the 335i, 435i, 535i, M2, M135i, and M235i. The stock cast internals handle 500–600whp reliably, but beyond that the rods and pistons become the limiting factor. Our N55 forged internals kit replaces the stock components with race-grade forged units capable of handling serious power builds on pump fuel, E30, or full E85.
What's Included:
Forged connecting rods — 4340 aircraft-grade steel, H-beam or I-beam design
Forged pistons — CP or equivalent specification, 84mm bore (stock)
ARP rod bolts included — 220,000 PSI rated
Wrist pins — standard or heavy duty (HD recommended for 850HP+ builds)
Balanced and matched set — within ±1.5g
Ring set included
Power Capability:
Standard configuration — 1,000HP capable
With HD wrist pins — up to 1,600HP capable
Suitable for pump fuel, E30, E85, and methanol builds
Compatible Vehicles:
BMW 335i — E90/E91/E92/E93 (2010–2013) · F30/F31/F34 (2011–2015)
BMW 435i — F32/F33/F36 (2013–2016)
BMW 535i — F10/F11/F07 (2009–2017)
BMW 640i — F06/F12/F13 (2011–2018)
BMW 740i — F01/F02 (2012–2015)
BMW M135i — F20/F21 (2012–2016)
BMW M235i — F22/F23 (2013–2016)
BMW M2 — F87 (2016–2018)
BMW X3/X4/X5/X6 xDrive35i — various years
All N55B30 variants — N55B30M0, N55B30O0, N55B30T0
Why Upgrade the N55 Internals?
The stock N55 uses cast connecting rods and pistons. While durable at moderate power levels, cast components crack under sustained high-boost operation. At 600–700whp+ the rods are the first failure point — typically bending or snapping under high-RPM boost spikes. Forged internals eliminate this risk entirely, giving you a foundation that can handle whatever turbo and fuelling combination you choose to run.