Reinforced head gasket Honda Civic X CR-V 1.5 turbo L15B7 L15BA L15BE

The Honda engines covered

The L15B7, L15BA and L15BE are turbocharged 1.5 litre four-cylinder petrol engines without VTEC, fitted to the Honda Civic X and CR-V V listed in the compatibility table below. Each has a single cylinder head and therefore takes one gasket.

The original gasket carries part number 12251-59B-004 on the L15B7 and the L15BE. Honda publishes neither its bore, nor its thickness, nor its construction. Sized for standard combustion pressure, it reaches its limit as soon as that pressure rises: clamping load drops, the head lifts and coolant finds its way into a cylinder.

Reinforced cylinder head gaskets

The gasket's hold also depends on the fasteners that clamp the head onto the block. A composite gasket is permanently crushed beyond 100 N/mm²; the 301 stainless steel of an MLS gasket withstands 517 N/mm², 5 times more, and returns to shape at every combustion. Replace any head bolt that is stretched or damaged. On this engine, tighten the head bolts in the manufacturer's sequence and to its torque.

This page presents part number C14019-024 from Cometic, the American maker of racing gaskets, in a single construction: the multi-layer steel MLS. Its bore is 73.5 mm and its thickness 0.61 mm. As a rule, the gasket bore chosen is at least 0.5 mm larger than the actual cylinder bore. It is sold individually, one gasket per engine.

Technical specifications

A gasket's volume is the free space it leaves above each cylinder. It adds to the combustion chamber and lowers the compression ratio: the thicker the gasket, the larger that volume. Here the single part number has a 73.5 mm bore.

Preparation and fitting

Before refitting, check the flatness of head and block with a straight edge and have the faces ground if necessary. The Cometic gasket comes pre-coated: do not apply any sealant. This check matters most after an overheating or when the removed gasket was leaking.

Technical guide

The construction offered

Cometic MLS A stack of stamped and riveted stainless steel sheets. The outer sheets carry active beads that surround every cylinder and every fluid passage. Moderate clamping is enough to seal and the bore stays stable: a versatile construction, from the tuned naturally aspirated engine to moderate boost. The part number C14019-024 on this page is offered in this construction.

Choosing bore and thickness

Gasket bore. The Cometic MLS C14019-024 comes in 73.5 mm, in that bore only.

Thickness. No thickness is published for the original gasket 12251-59B-004. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

As the original thickness is not published, use a dial gauge to measure how far the pistons stand above the block's gasket face, especially if the removed gasket is thicker than 0.61 mm: this reading gives the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American company created in 1989 and based in Concord, Ohio, specialised in engine gaskets and sealing solutions. It made its name with the custom gasket, made to the bore and thickness required and manufactured in the United States. Its MLS range also covers the L15B7 of the Honda Civic X.

Advantages over the original gasket

When a reinforced gasket becomes necessary

• Adding forced induction, or raising boost on an already turbocharged engine
• Cylinder rebored beyond what the bore of the original gasket, a figure Honda does not publish covers
• Looking for a compression ratio different from standard, higher or lower
• Engine that has already lost its gasket, or is consuming coolant
• Competition use, where the gasket goes through repeated temperature rises

Vehicle compatibility

OEM part number: 12251-59B-004 (L15B7, L15BE).

Important: the part number on this page only suits the L15B7, L15BA and L15BE engines: check the engine code of your Honda before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches its limit, the reinforced one takes over: under stronger combustion pressure it keeps its shape instead of crushing. This applies to a turbocharged engine whose boost is raised.

Fitting a bigger turbo, raising boost pressure or increasing the compression ratio puts the head gasket under strain first, as the weak link of the top end. A reinforced gasket prevents the leak, and with it a head removal far more expensive than the part itself. On a turbocharged 1.5 litre such as the L15B7, the extra pressure is felt at the gasket first.