Reinforced cylinder head gasket Honda J32A1 J35A1 J35A3

The Honda engines covered

The Honda petrol engines J32A1, J35A1 and J35A3, of 3.2 and 3.5 litres, are fitted to the Inspire, Lagreat, Shuttle and Odyssey models listed below.

The original gasket of the J35A1 carries part number 12251-PVJ-A01 and that of the J35A3 part number 12251-PGE-A01; Honda does not publish the one for the J32A1. Honda gives neither the bore, nor the thickness, nor the construction of these gaskets. They are calculated for standard pressure: when it rises, clamping drops, the cylinder head lifts and coolant enters a cylinder.

Reinforced cylinder head gaskets

The head gasket does not seal alone: the fasteners that clamp the head to the block contribute just as much. Beyond 100 N/mm², a composite gasket settles for good; the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and springs back to shape at every combustion.

This page offers the part numbers of Cometic, an American maker of competition gaskets, in a single construction: the multi-layer steel MLS. All the gaskets have a 90 mm bore and thicknesses from 0.69 to 3.56 mm, enough to adjust 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

Gasket volume is the void it provides above each cylinder. It comes on top of the combustion chamber and lowers the compression ratio, the more so the larger it is. Only compare these values between gaskets of the same bore.

Preparation and fitting

Before assembly, run a straight edge over the head and block faces to check they are flat, and have them machined if needed. Apply no sealing paste: Cometic gaskets are already coated on delivery.

Technical guide

The construction offered

MLS Cometic Stainless steel layers, stamped and then riveted to one another. The outer layers have active beads around each cylinder and each fluid passage. Moderate tightening is enough to seal and the bore barely distorts. This versatile construction suits anything from a tuned naturally aspirated engine to moderate boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS is offered in 90 mm (C4382), in that bore alone.

Thickness. Honda releases no thickness figure for the original gaskets of these engines. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

Before opting for a thickness below the original, measure with a dial gauge how far the pistons rise above the block face: this figure shows the clearance left between piston and cylinder head.

The brand

Cometic Gasket, Inc., an American company created in 1989 in Concord, Ohio, designs gaskets and sealing solutions for engines. It is known for the made-to-measure gasket, cut to the bore and thickness ordered. All manufacturing stays in the United States, with 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 original gaskets, a value Honda does not give 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: 12251-PVJ-A01 and 12251-PGE-A01.

Important: the part numbers on this page cover the Honda engines J32A1, J35A1 and J35A3: check your vehicle's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket is no longer enough, the reinforced gasket takes over: under a higher combustion pressure it keeps its shape and does not crush.

As soon as power goes up through a turbo, a supercharger or a raised compression ratio, the head gasket bears the heaviest loads of the top end, and every further rise in boost adds to them. A reinforced gasket prevents the leak and the head removal that follows.