Cometic C4238-030 Acura Integra B18A1/B18B1 MLS Head Gasket – 81mm Bore, .030″ Thickness

Why Choose a Cometic MLS Head Gasket for Your B18 Engine?

Honda’s B18A1 and B18B1 engines have earned a reputation for reliability, strong aftermarket support, and adaptability to performance builds.

However, cylinder head sealing becomes particularly important when rebuilding an aging engine or increasing cylinder pressure through forced induction.

The Cometic C4238-030 uses multi-layer steel construction designed to maintain sealing pressure around the combustion chambers while accommodating normal thermal expansion between the cylinder head and engine block.

Its engineered sealing surfaces provide a durable alternative to conventional composite gasket designs when the mating surfaces meet the manufacturer’s requirements.

For a properly prepared engine, this construction can provide reliable sealing in both factory-style rebuilds and modified applications.

FYI: How to Diagnose a Blown B18 Head Gasket

A failed head gasket can cause coolant loss, overheating, poor compression, persistent white exhaust vapor, and combustion gases entering the cooling system.

Before ordering replacement parts, identify the underlying cause. Installing a new head gasket without correcting a warped cylinder head or cooling-system problem can result in another failure.

For a practical repair walkthrough, read How to Fix a B18 Blown Head Gasket on My Pro Street. The guide uses a 1997 Acura Integra LS equipped with the B18B1 engine—the exact engine family supported by this Cometic gasket. It covers cylinder head removal, failure symptoms, and preparation for reassembly.

FYI: What Does .030-Inch Head Gasket Thickness Mean?

The Cometic C4238-030 has a compressed thickness of .030 inches, approximately 0.762mm.

Gasket thickness influences piston-to-head clearance and combustion chamber volume. A thinner gasket may increase static compression ratio compared with a thicker gasket, but only when the engine’s other dimensions remain unchanged.

An 81mm gasket opening also needs to be checked against the finished cylinder bore. Engines with oversized pistons may require a different gasket bore.

Cometic offers alternative B18A1/B18B1 gasket bore sizes, including 81.5mm, 82mm, 83mm, 84mm, and 85mm, depending on the application.

How to Install a Cometic MLS Head Gasket on an Acura Integra

1. Diagnose the original head gasket failure and correct any overheating problems.

2. Remove the cylinder head following the applicable Acura service manual.

3. Inspect the aluminum cylinder head for warpage, cracking, and corrosion.

4. Check the engine block deck for flatness and damage.

5. Confirm that both sealing surfaces meet Cometic’s MLS surface-finish requirements.

6. Clean the mating surfaces without damaging the aluminum head or iron block.

7. Install the new gasket over the cylinder head alignment dowels.

8. Install appropriate head bolts or studs and follow the specified tightening procedure.

9. Reassemble the timing components and verify camshaft timing.

10. Refill and bleed the cooling system, then inspect for leaks.

Helpful repair resource: If cylinder head fastener threads are damaged during disassembly, see How to Repair a Stripped Honda B-Series Engine. This My Pro Street technical article discusses damaged head fastener threads and repair considerations for B-series engines.

Frequently Asked Questions

Does the Cometic C4238-030 fit a 1997 Acura Integra LS?

Yes. The 1997 Acura Integra LS equipped with the factory B18B1 1.8L non-VTEC engine is a listed application.

Will it fit a 1992 Acura Integra GS?

Yes, when equipped with the original B18A1 non-VTEC engine.

Does this gasket fit an Acura Integra GS-R or Type R?

No. The GS-R and Type R use different VTEC cylinder head configurations. Cometic C4231-030 is an 81mm MLS gasket listed for applicable B18C VTEC engines.

Can the C4238-030 be used on a turbocharged B18B1?

It can be considered for a properly engineered turbocharged engine. Reliable sealing depends on cylinder pressure, tuning, surface preparation, and head clamping. The gasket does not have a universal horsepower or boost-pressure rating.

Does the product include a complete gasket kit?

No. Cometic C4238-030 includes one cylinder head gasket. For a more comprehensive repair, Cometic separately offers B18A1/B18B1 top-end gasket kits.

Restore Your Acura Integra’s Cylinder Head Sealing

The Cometic C4238-030 MLS Head Gasket combines three-layer stainless steel construction, an 81mm gasket bore, and .030-inch compressed thickness for compatible Acura Integra B18A1 and B18B1 engines.

Whether you’re repairing a blown head gasket or preparing your Honda B-series engine for a performance rebuild, correct gasket selection and installation are essential for long-term reliability.

Shop engine rebuilding components and performance replacement parts at Pro Street Online.