Reinforced head gasket Nissan 3.0 3.5 V6 VQ30DE VQ35DE

The Nissan engines covered

The petrol engines VQ30DE of 3.0 litres and VQ35DE of 3.5 litres, V6 units with twenty-four valves, power the Nissan, Infiniti and other models in the compatibility table below. Each takes two cylinder head gaskets, one per cylinder bank.

Two original gaskets are listed: 11044-38U01 for the VQ30DE and 11044-EA200 for the VQ35DE. Nissan publishes neither the bore, nor the thickness, nor the construction of the first; for the second, only the bore is known, 96 mm. They are calculated for the standard combustion pressure: when that rises, the clamping load fades, the cylinder head lifts off the block and coolant finds its way into a cylinder.

Reinforced cylinder head gaskets

Sealing does not rest on the gasket alone: the fasteners, which press the cylinder head against the block, provide half of it. Beyond 100 N/mm² of stress, a composite gasket settles for good; the 301 stainless steel of MLS gaskets withstands up to 517 N/mm², 5 times more, and recovers its shape with every combustion.

This page presents two Cometic part numbers, an American maker of competition gaskets, in a single construction: MLS. Bore of 97 mm, thickness of 0.69 mm. By convention, the gasket bore exceeds the cylinder bore by at least 0.5 mm. The engine is a V6 that takes one gasket per cylinder bank: order both part numbers, one for each bank.

Technical specifications

Gasket volume is the space the gasket keeps free above each cylinder. Added to the combustion chamber, it lowers the compression ratio; only a comparison between gaskets of the same bore is meaningful.

Preparation and fitting

Before fitting the gasket, check with a straight edge that the cylinder head and block are flat, and have them resurfaced if needed. Cometic ships it already coated: add no sealing paste.

Technical guide

The construction offered

Cometic MLS Embossed stainless steel sheets, laid one on another and then riveted. The outer sheets carry active beads around every cylinder and every fluid passage. Moderate tightening is enough to seal, and the bore deforms little. A versatile gasket, from the prepared naturally aspirated engine up to moderate forced induction.

Choosing bore and thickness

Gasket bore. The Cometic MLS gasket comes here only in 97 mm (C4509-027, C4510-027).

Thickness. Nissan publishes no thickness for the original gaskets. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

Without a published original thickness, use a dial gauge to measure by how much the pistons stand proud of the block face, especially if the removed gasket is thinner than 0.69 mm: the reading gives the free distance between piston and cylinder head.

The brand

Founded in 1989 in Concord, Ohio, Cometic Gasket, Inc. is an American company specialising in gaskets and sealing parts for engines. Its reputation comes from the custom gasket, cut to the bore and thickness wanted, and from production carried out entirely in the United States from local raw 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 97 mm bore of the gasket offered 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: 11044-38U01, 11044-EA200.

Important: the part numbers on this page fit only the engines VQ30DE and VQ35DE, which take two gaskets, one per cylinder bank: check your vehicle's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches its limit, the reinforced gasket takes over: under a higher combustion pressure it does not get crushed and keeps its geometry.

As soon as a turbo, a supercharger or a raised compression ratio comes into play, the head gasket is the first part of the top end to give way. A reinforced gasket rules out the leak and the cylinder head removal that would follow, far costlier than the part itself.