SpeedFactory K20A/K20Z H-Beam Connecting Rods

Whether it's a boosted K20A2 RSX Type-S, a K20Z3 Civic Si seeing track duty, or a high-compression all-motor build spinning past 9,000 rpm, the stock K20 rods are the fuse in the system. The SpeedFactory Racing K20A/Z H-beam connecting rods replace that fuse with forged 4340 chromoly rated for over 900 hp, at a price that leaves room in the budget for pistons and a proper tune.

What It Is and Why It Works

This is a set of four 138.98mm center-to-center rods for the K20A, K20A2, K20Z1, and K20Z3. Each rod is forged from SAE 4340 chromoly, 100% CNC machined, multi-stage heat treated, magnafluxed to catch internal flaws, and shot-peened to relieve stress. Precision alignment dowels locate the rod caps, keep the big end bore round, and eliminate cap walk under load. The pin end runs a bronze alloy bushing with dual offset oiling holes for floating wrist pins.

SpeedFactory includes 3/8 inch ARP2000 rod bolts rated at 220,000 psi, ARP assembly lube, and instructions in the box, and every set is weight matched to within 1 gram. At 538 grams per rod, they're light enough for the high-revving all-motor crowd while carrying a power rating that covers essentially any street or drag K20 build. These also cover the JDM K20A family, so DC5 Integra Type R, EP3 Civic Type R, and FD2 bottom ends are all fair game, along with any K20 swapped into an EG, EK, or DC2.

Specs

Fitment

Factory applications cover the K20A2 and K20Z1 in the RSX Type-S and the K20Z3 in the 8th gen Civic Si. JDM K20A engines share the same bottom end dimensions.

These do not fit the K20A3. That's the engine in the base RSX and the 2002-2005 EP3 Civic Si, so if that's your bottom end, these rods are not compatible. The pin end fits most aftermarket pistons without additional machining, and OEM style pistons will not work at all.

What to Know Before You Buy

Check your engine code before you order, not after the box shows up. The K20A3 exclusion catches people constantly because the EP3 Si looks like it should take the same parts as an RSX Type-S, and it doesn't. If you're building an EP3 and want these rods, the honest answer is that most EP3 guys doing a serious build swap in a K20A2 or K20Z bottom end anyway, and at that point these rods are exactly right.

Plan pistons and rods as one order. The bushed pin end is built for aftermarket forged pistons, so stock slugs are off the table. The typical recipe we see is these rods, forged pistons, King or ACL bearings, and ARP head studs, which holds serious boost on a good tune. If you're chasing a 9,000+ rpm all-motor setup, talk to your builder about stepping up from the included ARP2000 bolts to a stronger rod bolt spec before assembly.

Standard machine shop rules apply: verify bearing clearances, torque the ARP hardware with the included lube and a stretch gauge, and confirm balance during assembly even though the set arrives matched to within a gram. And if your build is actually a K24 block with a K20 head, you want the K24 version of this rod, not this one. Buy by the block.