Cometic L15B7 MLS Head Gasket 73.5mm .024in Civic Si 1.5T

Cometic L15B7 MLS Head Gasket 73.5mm .024in Civic Si 1.5T

The head gasket is the known weak point of the L15B7 once you turn the boost up. Tuned 2017-2020 Civic Si and 1.5T Civic owners have been fighting head lift and slow coolant loss for years, and this Cometic L15B7 head gasket (part number C14019-024) is the multi layer steel fix most of them land on when the factory composite gasket taps out.

What It Is and Why It Works

This is Cometic's HP series MLS head gasket for the Honda 1.5 liter turbo family: L15B7, L15BA, and L15BE. Three layers of stainless steel replace the single factory gasket, with embossed outer layers coated in Viton that stays sealed through heat cycles up to 482 degrees F. The embossing spreads clamp load evenly across the deck, so there is no re torque after installation and no sealant required. It is built for the aluminum head on aluminum block setup these engines use.

Bore size matters more than anything else on this page. The L15B7's cylinders measure 73mm, and this gasket's 73.5mm bore is intentionally a half millimeter larger. A head gasket bore always needs to be slightly larger than the actual cylinder bore so the sealing ring sits on the deck surface, never overhanging the cylinder. If a gasket's listed bore is smaller than your pistons, it is the wrong gasket, full stop.

Thickness is the other decision. This is the .024 inch compressed version, and Cometic also makes this gasket in .031 and .054 inch. Thicker gaskets increase deck clearance and lower static compression, thinner ones raise it. Run the .024 if you want to keep compression close to where a healthy stock engine sits, and step up in thickness only if you are compensating for a decked block or deliberately pulling compression out of a high boost build.

Specs

Fitment

Cometic lists this gasket by engine, so any 1.5T Civic or CR-V running the L15B7, L15BA, or L15BE is covered, including 2016 Civic 1.5T models. It does not fit the 2.0T Civic Type R; the K20C1 uses a completely different 86mm bore gasket.

What to Know Before You Buy

If you are pulling the head on a tuned car, do the job once. The factory head bolts are torque to yield, and the community consensus on boosted L15B7 builds is to pair this gasket with aftermarket head studs, ARP or equivalent, for consistent clamp load. An MLS gasket is also only as good as the surfaces it clamps: Cometic calls for a deck and head finish of 50 RA or smoother, so if the head has been overheated, have it checked for flatness and resurfaced before assembly. While you are in there, budget for new coolant, a thermostat, and a fresh set of TGV and intake gaskets so you are not doing this twice. If your car is stock and not leaking, you do not need this part; it earns its keep on tuned, tracked, or previously overheated engines.