Reinforced head gasket Toyota 1GR-FE

The Toyota engines covered

The 1GR-FE is a petrol V6 of 4.0 litres and 24 valves, fitted to the Toyota Land Cruiser and Land Cruiser Prado, 4Runner, FJ Cruiser, Fortuner, Hilux, Tacoma and Tundra, as well as the Lexus GX, as detailed in the compatibility table below.

This V6 takes two original head gaskets, one per cylinder bank, numbered 11115-31090 and 11116-31070. Toyota publishes neither their bore, nor their thickness, nor their construction. They are calibrated for the standard combustion pressure: as soon as it rises, the clamping load weakens, the head lifts and coolant seeps into a cylinder.

Reinforced cylinder head gaskets

The gasket does not seal on its own: it holds thanks to the fasteners that press the head against the block. Beyond 100 N/mm² of stress, a composite gasket is crushed for good; the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and recovers its shape with every combustion.

This page groups the Cometic MLS gaskets, from an American maker of competition gaskets, in 95.5 and 96.5 mm bores and in thicknesses from 0.69 to 3.56 mm, enough to set the compression ratio to suit the build. As a general rule, a gasket bore at least 0.5 mm larger than the actual cylinder bore is chosen. Each part number is sold individually, and the engine takes two, one for each cylinder bank.

Technical specifications

The gasket volume is the free space it leaves above each cylinder. It adds to the combustion chamber and lowers the compression ratio; only gaskets with the same bore can be compared with each other.

Preparation and fitting

Before fitting, check the flatness of the cylinder head and the block with a straightedge and have any distorted surface machined. Cometic supplies this gasket already coated: add no sealing paste.

Technical guide

The construction offered

MLS Cometic Stainless steel sheets, embossed, stacked and riveted. The outer sheets carry active beads around every cylinder and every fluid passage. A moderate clamping load is enough to seal, and the bore distorts little. A versatile gasket, from the tuned naturally aspirated engine to moderate forced induction.

Choosing bore and thickness

Gasket bore. The Cometic MLS comes in 95.5 mm (C4556 for the left bank, C4557 for the right bank) and in 96.5 mm (C14054 on the left, C14045 on the right, plus C14058 and C14065).

Thickness. No thickness is given by Toyota for its standard-fit gaskets. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

With no published original thickness, use a dial gauge to read how far the pistons stand above the block deck, especially for a thickness thinner than the removed gasket: that reading gives the real clearance between piston and cylinder head.

The brand

Cometic Gasket, Inc. is an American maker of engine gaskets and sealing solutions, founded in 1989 and based in Concord, Ohio. Its speciality is the made-to-order gasket, cut to the bore and thickness requested, and everything is made 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 95.5 and 96.5 mm bores of the gaskets 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: 11115-31090 and 11116-31070.

Important: these part numbers are for the 1GR-FE engine: check your vehicle's engine code before ordering, and order the part number for each cylinder bank.

Why switch to a reinforced gasket?

When the original gasket reaches its limit, the reinforced gasket takes over: under higher combustion pressure it does not crush and keeps its shape.

A turbo, a supercharger or a raised compression ratio load the head gasket first, the weak link of the top end. The reinforced gasket prevents the leak, and with it the removal of the cylinder head, a job out of all proportion to its price.