Reinforced cylinder head gasket Opel 3.0 C30SE C30SEJ

The Opel engines covered

The 3.0 litre Opel petrol engines C30SE and C30SEJ, with twenty-four valves, are fitted to the Omega A, Senator B, Carlton Mk III, Senator Mk II and Bitter Type 3 models listed below.

This original gasket carries the part number 607973. Its bore is 97 mm; Opel publishes neither its construction nor its thickness. It is designed for standard combustion pressure: when that pressure rises, the clamping load weakens, the cylinder head lifts and coolant seeps into a cylinder.

Reinforced cylinder head gaskets

The seal does not come from the gasket alone: it depends on the fasteners, which press the cylinder head onto the block. With the O-Ring the roles are shared: the stainless ring closes the combustion chamber alone, the body manages the water and oil circuits, and the block does not have to be machined.

This page presents the part number from Athena, an Italian maker of racing gaskets, for a single construction: the O-Ring, a steel sheet faced with aramid fibre and fitted with a stainless ring. The gasket has a 97 mm bore, the same as the original gasket, and a thickness of 1.60 mm. 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 it keeps free above each cylinder. It comes on top of the combustion chamber and therefore reduces the compression ratio. Only a comparison between gaskets of the same bore makes sense.

Preparation and fitting

Before fitting the gasket, check the flatness of the cylinder head and block with a straight edge and have them machined if needed. Athena supplies it ready to fit: use no sealing paste.

Technical guide

The construction offered

Athena O-Ring A steel sheet covered with asbestos-free aramid fibre, surrounded at each cylinder by a stainless steel compression ring. The ring transfers the clamping force to a narrow band, where the seal is decided, while a silicone bead isolates the water and oil circuits. It is the construction that best withstands high pressures in the range.

Choosing bore and thickness

Gasket bore. The Athena O-Ring is offered in 97 mm (330238R), in that bore only.

Thickness. Opel does not publish the thickness of the original gasket. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

Since the original thickness is not published, measure with a dial gauge how far the pistons stand above the block, especially if the removed gasket is thicker than 1.60 mm: that value gives the clearance left between piston and head.

The brand

An Italian maker of gaskets and engine parts, Athena S.p.A. is based in Alonte, in the Veneto, where its head office and main plant stand. The group also runs sites in Spain, the United States, Brazil and India. Its multi-layer gaskets are fitted by car makers as original equipment, and its competition range is entirely designed and made in Italy.

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 97 mm bore of the original gasket 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: 607973.

Important: the part number on this page fits only the engines C30SE and C30SEJ: check your vehicle's engine code before placing an order.

Why switch to a reinforced gasket?

When the standard gasket can no longer keep up, the reinforced gasket steps in: at higher combustion pressure it keeps its shape and does not get crushed.

When power climbs thanks to a turbo, a supercharger or a raised compression ratio, the head gasket is the first part of the top end to suffer. A reinforced gasket rules out the risk of a leak and the cylinder head removal that would follow, with the labour and parts cost of doing the job twice.