Reinforced head gasket Toyota 2RZ-FE 3RZ-FE

The Toyota engines covered

The Toyota 2RZ-FE (2.4 litres, 2438 cm³) and 3RZ-FE (2.7 litres, 2694 cm³) are 16-valve petrol engines. They power the Hilux, Tacoma, Hiace, Land Cruiser, 4Runner and the other models in the compatibility table below.

The original gasket carries Toyota part numbers 11115-75030 and 11115-75031. Toyota publishes neither its bore, nor its thickness, nor its construction. Each engine takes a single cylinder head gasket, sized for the standard combustion pressure; when that pressure rises, the clamping load relaxes, the head lifts a little and coolant leaks into a cylinder.

Reinforced cylinder head gaskets

Sealing does not depend on the gasket alone: it also relies on the fasteners that clamp the head onto the block. 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 regains its shape at every combustion. Also inspect the head bolts and replace any that are stretched or damaged, on your Toyota.

This page gathers 18 Cometic part numbers, from the American maker of racing gaskets, in one single construction: MLS, multi-layer steel. Only one bore is offered, 97 mm, in 18 thicknesses from 0.69 to 3.56 mm. An engine uses just one gasket: order a single part number. These thicknesses let you set 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

The volume of a gasket is the free space it leaves above each cylinder; it adds to the combustion chamber and lowers the compression ratio. Compare only gaskets with the same bore: 97 mm here.

Preparation and fitting

Before refitting, check the flatness of the head and block mating faces with a straightedge and have them ground if necessary. Cometic gaskets are supplied already coated: apply no sealing paste. Also clean the mating faces carefully before fitting, on the head as on the block of your Toyota.

Technical guide

The construction offered

Cometic MLS Several stainless steel sheets, stamped and joined by rivets. Each outer sheet has active beads that surround the cylinders and the fluid passages. A moderate clamping load is enough to seal, and the bore distorts very little. This versatile gasket goes from the tuned naturally aspirated engine to light boost. Every part number on this page is offered in this construction. Here it serves the Toyota 2RZ-FE and 3RZ-FE engines.

Choosing bore and thickness

Gasket bore. The Cometic MLS comes in a single bore, 97 mm (C4245).

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

Before choosing a thickness below the original, use a dial indicator to read how far the pistons rise above the block deck: this gap gives the clearance left between piston and head. Take the reading on each cylinder of this engine.

The brand

Cometic Gasket, Inc., an American company founded in 1989 and based in Concord, Ohio, designs and manufactures gaskets and sealing parts for engines. It is known for made-to-order gaskets, cut to the bore and thickness requested and produced entirely in the United States from American materials. For the Toyota engines on this page, its part numbers come in a single bore.

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 these gaskets 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: 11115-75030 and 11115-75031.

Important: the part numbers on this page suit only the 2RZ-FE and 3RZ-FE engines: check the engine code of your Toyota before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches its limit, the reinforced gasket steps in: under higher combustion pressure it keeps its shape instead of settling. For the Toyota engines on this page, it is justified as soon as the engine exceeds its original output.

Add a turbo, raise the compression ratio or rev higher with sharper camshafts: whichever you do, the cylinder head gasket becomes the weak point of the tuned engine. A reinforced gasket prevents the leak, and the head removal that follows, which costs far more than the gasket. On these Toyota engines it is the first item to address once the original output is exceeded.