Cometic K20 K24 Exhaust Manifold Gasket for RSX, Si, TSX

Cometic K-Series MLS Exhaust Manifold Gasket - Part #C4162-030

Every header install on a K20A2 RSX, a K20Z3 Si, or a K-swapped EG or EK ends the same way: the factory exhaust manifold gasket is crushed, cracked, or half-stuck to the head, and the auto parts store wants to sell you a paper one. Cometic's C4162-030 is the .030 inch MLS gasket cut for the K-series exhaust port, and it's what we'd put between a K20 or K24 head and a 4-2-1 header, a stock manifold, or a turbo manifold.

What It Is and Why It Works

Cometic builds this gasket from embossed stainless steel layers, the same construction as their MLS head gaskets, and cuts the four ports at 1.975 by 1.730 inches to match the stock K-series head. The embossments spring back with every heat cycle and hold their torque set, so the gasket doesn't loosen the manifold nuts over time or push out between the ports the way a fiber gasket will after a few hundred heat cycles on a header. It seals an aluminum head against a cast iron manifold or a stainless header without sealant, and it survives the thermal shear between those two materials. It interchanges with the Honda 18115-PNB-003 gasket and covers the K20A2, K20Z1, K20Z3, K24A1, K24A2, K24A3, K24A4, K24A8, and K24Z1, which means one part number handles the RSX Type-S, 06-11 Civic Si, 04-08 TSX, 03-07 Accord 2.4, and 02-06 CR-V, plus the K24 and K20 combinations people swap into 90s Civics and Integras.

Specs

Fitment

Also correct for any K20A2, K20Z1, K20Z3, or K24A swap into an EG, EK, DC2, or other chassis. Cometic's engine list does not include the K20A3 found in the RSX Base and EP3 Civic Si; the port layout is the same family, but confirm against your manifold before ordering for one of those. V6 Accords and the K24Z3 and K24Z7 cars from 2008 on are not covered.

What to Know Before You Buy

MLS wants flat, clean flanges. Scrape the head face down to bare aluminum and check an aftermarket header flange with a straightedge before you trust it; a cheap header with a wavy flange will leak with any gasket, and this one won't hide it. Install it dry, with no sealant on the gasket itself, and put anti-seize on the studs, not the sealing surface. Torque the nuts to factory spec in a cross pattern and re-check them after the first few heat cycles. If the studs are rusted or the nuts rounded on the way off, replace them; a fresh set of 8mm studs and copper nuts costs less than the gasket and saves the next person a broken stud. Order a second one if you're doing a header now and a turbo manifold later, since you'll want a new gasket each time the manifold comes off.