Reinforced cylinder head gasket Saab 9000 900 9-3 2.0 2.3 16V B204I B204L B204E B204R B204S B234I B234L B234R B234E

The Saab engines covered

The Saab B204I, B204L, B204E, B204R, B204S, B234I, B234L, B234R and B234E petrol engines, of 2.0 and 2.3 litres, are fitted to the Saab 9000, 900 II and 9-3 models listed below.

The original gasket carries the part number 91 44 528. Saab publishes neither the bore, nor the construction, nor the thickness. It is designed for standard combustion pressure: as that pressure rises, the clamping load relaxes, the cylinder head lifts and coolant seeps into a cylinder.

Reinforced cylinder head gaskets

Sealing does not depend on the gasket alone: the fasteners that clamp the head onto the block play an equal part. Above 100 N/mm², a composite gasket settles for good; the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and recovers its shape at each combustion.

This page brings together the part numbers of Cometic, an American maker of racing gaskets, in two constructions: the multi-layer steel MLS and the CFM-20, with a steel core coated in a soft compound. Every gasket has a 91 mm bore and thicknesses from 0.69 to 3.56 mm, enough to 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

Gasket volume is the space left free above each cylinder. It is added to the combustion chamber, and the larger it is, the lower the compression ratio falls. Only compare these values between gaskets of the same bore.

Preparation and fitting

Before fitting, rest a straight edge on the head and block gasket faces to confirm they are flat, then have them resurfaced if required. There is no need to coat the gaskets: Cometic gaskets arrive already coated.

Technical guide

The two constructions offered

	CFM-20 Cometic A galvanized steel core covered on both faces with a soft asbestos-free compound made of aramid fibres, mineral fillers and elastomer binders. This laminated construction, part metal and part fibre, combines the strength of steel with the softness of the compound. It is offered here as a single gasket, with a 91 mm bore and a thickness of 1.09 mm.
	MLS Cometic Stainless steel sheets stamped and riveted together. The outer sheets carry active beads around each cylinder and each fluid passage. A moderate tightening torque is enough to seal and the bore distorts little. This versatile solution suits the tuned naturally aspirated engine through to moderate boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS (C4974) and the Cometic CFM-20 (C14107) are offered in 91 mm, in that bore only.

Thickness. The thickness of the original gasket is not published by Saab. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

If you opt for a thickness below the original one, use a dial gauge to measure how far the pistons sit above the block deck: this reading shows the clearance left between piston and head.

The brand

Cometic Gasket, Inc., an American company founded in 1989 in Concord, Ohio, makes engine gaskets and sealing solutions. Its know-how is the made-to-measure gasket, cut to the bore and thickness requested. Manufacturing stays entirely in the United States, with American materials.

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, not published by Saab 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: 91 44 528.

Important: the part numbers on this page fit only the B204I, B204L, B204E, B204R, B204S, B234I, B234L, B234R and B234E engines: check your vehicle's engine code before placing an order.

Why switch to a reinforced gasket?

When the original gasket reaches the end of what it can do, the reinforced gasket steps in: under higher combustion pressure it keeps its shape and does not settle.

As soon as you fit a turbo or a supercharger, or raise the compression ratio, the cylinder head takes higher loads and its gasket becomes the weak link. A reinforced gasket rules out the leak and the head removal that would follow.