Reinforced head gasket Volvo B19 B200 B21 2.0 2.1

The Volvo engines covered

The B19A, B19E, B19ET, B200E, B200ET, B200F and B200K are 2.0 litre petrol engines; the B21A, B21E, B21F, B21FT and B21ET are 2.1 litre petrol engines. They power the Volvo 240, 260, 340-360, 740, 940 and 960 models listed in the compatibility table below.

The original gasket carries part number 1 378 645-4. Volvo publishes neither its bore, nor its thickness, nor its construction. Each engine takes one cylinder head gasket, sized for the standard combustion pressure; when that pressure climbs, the clamping force eases, the head lifts slightly and coolant seeps into a cylinder.

Reinforced cylinder head gaskets

Sealing does not rest on the gasket alone but also on the fasteners that press the head onto the block. Beyond 100 N/mm², a composite gasket compresses for good; the 301 stainless steel of MLS gaskets takes 517 N/mm², 5 times more, and recovers its shape at every combustion. Also check the condition of the head bolts and replace any that are stretched or damaged.

This page brings together 21 Cometic part numbers, from the American maker of competition gaskets, for a single construction: MLS, multi-layer steel. Four bores are offered: 92 mm (C4498), 92.5 mm (H2554SP4051S), 93 mm (H2554SP8051S) and 94.5 mm (H2554SP5051S). The 92 mm bore comes in 18 thicknesses from 0.69 to 3.56 mm; the other three come in 1.30 mm only. An engine takes a single gasket: order one part number. The thicknesses offered let you adjust the compression ratio without touching the pistons or the cylinder head. As a rule, the gasket bore chosen is at least 0.5 mm larger than the actual cylinder bore. Each part number 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. Compare only gaskets of the same bore: 92, 92.5, 93 or 94.5 mm here.

Preparation and fitting

Before reassembly, check the flatness of the head and block mating faces with a straightedge and have them resurfaced if needed. Cometic gaskets arrive already coated: do not apply any sealing paste. Also clean the gasket faces thoroughly before fitting.

Technical guide

The construction offered

Cometic MLS Several stainless steel sheets, stamped and riveted together. Each outer sheet carries active beads tracing the outline of every cylinder and fluid passage. A moderate clamping load is enough to seal, and the bore distorts very little. This versatile gasket suits anything from a tuned naturally aspirated engine to light boost. All the part numbers on this page are offered in this construction.

Choosing bore and thickness

Gasket bore. The Cometic MLS is offered in 92 mm (C4498), 92.5 mm (H2554SP4051S), 93 mm (H2554SP8051S) and 94.5 mm (H2554SP5051S, for the B21 engines only).

Thickness. No thickness is published for the original gasket 1 378 645-4. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

To choose a thickness below the original, first use a dial gauge to read how far the pistons stand above the block face: that figure gives the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American company founded in 1989 and based in Concord, Ohio, which designs and builds gaskets and sealing parts for engines. It earned its name with made-to-measure gaskets, cut to the bore and thickness required, all made in the United States from American materials. Its part numbers for these Volvo engines are offered here in four bores.

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 92 to 94.5 mm bores of these gaskets 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: 1 378 645-4.

Important: the part numbers on this page suit only the B19A, B19E, B19ET, B200E, B200ET, B200F, B200K, B21A, B21E, B21F, B21FT and B21ET engines: check your Volvo's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket is no longer enough, the reinforced gasket replaces it: under higher combustion pressure it keeps its shape instead of collapsing. For the Volvo models on this page, it is the answer as soon as the engine goes beyond its original output.

Whether you add a turbo, raise the compression ratio or rev higher with livelier cams, the cylinder head gasket becomes the weak link of a high-output engine. A reinforced gasket prevents the leak and the head removal that goes with it, far costlier than the gasket. On these Volvo engines, the reinforced gasket is the first item to address once you go beyond the original output.