Reinforced cylinder head gasket Nissan Skyline GT-R Stagea RB26DETT

The Nissan engines covered

The RB26DETT is the 2.6-litre twin-turbocharged petrol engine of the Nissan Skyline GT-R R32 (BNR32), R33 (BCNR33) and R34 (BNR34) and of the Stagea 260RS (WGNC34) in the compatibility table below. The head gasket is sold singly, one per engine.

The original gasket carries part number 11044-05U16. Nissan does not publish its bore, its thickness or its construction. It is sized for the standard combustion pressure: when that rises, the clamping load slackens, the head lifts and coolant gets into a cylinder.

Reinforced cylinder head gaskets

The gasket does not seal on its own: the fasteners that press the head onto the block count just as much. A composite gasket settles for good above 100 N/mm², whereas the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and springs back with every combustion. With the O-Ring, the stainless ring isolates the combustion chamber on its own, while the gasket body closes off water and oil.

This page gathers 59 part numbers from two racing manufacturers, Athena and Cometic, in three constructions: the stainless-ring O-Ring and the multi-layer MLS from Athena, the multi-layer MLS from Cometic. Bores run from 86 to 88 mm and thicknesses from 0.686 to 3.556 mm, enough to tune the compression ratio without touching the pistons or the 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 space it leaves free above each piston. It adds to the combustion chamber and lowers the compression ratio by as much. Only compare this value between gaskets of the same bore.

Preparation and fitting

Before fitting, check the flatness of the head and the block with a straightedge, and have whichever is warped machined. Add no sealant: Athena and Cometic supply their gaskets already coated.

Technical guide

The three constructions offered

	O-Ring / Cut Ring Athena A steel body loaded with asbestos-free aramid, around which a stainless ring is crimped on every cylinder. The ring concentrates the clamping load on a narrow band, exactly where sealing is won, and a silicone bead closes the water and oil passages. It is the construction that holds out longest against high combustion pressures.
	MLS Athena Two to five sheets of AISI 301 stainless steel, laser cut, embossed and riveted. Around every cylinder a folded sheet, the Gas Stopper, sends the clamping load back toward the combustion chamber, while embossed ridges keep water and oil apart. The outer faces are coated: one layer withstands heat and makes up for small flaws in block and head, a silicone layer stops the gasket sticking at removal. It is Athena's all-steel solution, from the tuned naturally aspirated engine to moderate boost. The embossed ridges act like springs: they recover their shape as the engine heats up and cools down, which keeps the sealing pressure steady across the whole rev range.
	MLS Cometic Stamped stainless steel sheets, stacked and riveted together. The outer sheets carry active ridges around each cylinder and each fluid passage. A moderate clamping load is enough to seal and the bore moves little: a versatile construction, from the tuned naturally aspirated engine to moderate boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS comes in 86 mm (C4319), 87 mm (C4320) and 88 mm (C4321), from 0.686 to 3.556 mm; the Athena MLS in 87.5 mm (338146R and 338315R); the Athena O-Ring in 87.5 mm (330089R) and 88 mm (330133R and 330134R).

Thickness. Nissan gives no thickness for its 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, use a dial gauge to read how far the pistons stand above the block's gasket face: it gives the clearance left between piston and head, especially with the thinnest options.

The two brands

	Athena S.p.A. is an Italian company that specialises in gaskets and engine parts. Its head office and main plant are in Alonte, in Veneto, with further sites in Spain, the United States, Brazil and India. Several carmakers fit its multi-layer gaskets as original equipment, and the competition range is designed and made in Italy.
	Cometic Gasket, Inc. is an American maker of engine gaskets and sealing solutions, founded in 1989 in Concord, Ohio. Its speciality is the gasket made to order, at the bore and thickness you want, produced entirely in the United States from 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 gaskets offered (86 to 88 mm) 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: 11044-05U16.

Important: these gaskets are listed for the RB26DETT engine in the table below (Skyline GT-R R32, R33, R34 and Stagea 260RS): check your vehicle's engine code before ordering, then choose the bore and thickness you want.

Why switch to a reinforced gasket?

When the standard gasket reaches its limits, the reinforced gasket takes over: under higher combustion pressure it keeps its shape instead of settling.

A tuned engine, boosted harder or compressed more, puts the head gasket to the test first. A reinforced gasket avoids the leak and, above all, a second head removal, a job far dearer than the part. Choosing the right gasket up front costs far less than repeating the whole job a second time.