When building or rebuilding a high-performance engine, the head gasket is one of the most critical components separating a reliable powerhouse from a costly failure. This thin yet mighty seal sits between the engine block and cylinder head, containing combustion pressures that can exceed 1,000 psi in boosted applications while also managing coolant and oil passages. Choosing the right head gasket means balancing sealing ability, material strength, and application-specific requirements. In this guide, we compare three leading options: Cometic, Fel-Pro, and multi-layer steel (MLS) gaskets. We’ll break down their construction, strengths, weaknesses, and real-world performance to help you make an informed decision for your build.

Understanding Head Gaskets – More Than Just a Seal

Before diving into brand comparisons, it’s essential to understand what a head gasket does and why material matters. The head gasket must handle extreme thermal cycling, high-pressure combustion events, and chemical exposure from coolant and oil. A failure can lead to coolant mixing with oil, loss of compression, or even catastrophic engine damage.

Head gaskets come in several construction types:

  • Composite (graphite or fiber) – Affordable and forgiving of minor surface imperfections, but limited in high-pressure applications. Often used in stock or mild street engines.
  • Multi-layer steel (MLS) – Multiple layers of spring steel with a coating (e.g., Viton or rubber) for sealing. Extremely strong and popular for boosted and high-compression builds.
  • Copper – Often used in race engines with O-ringed blocks; requires precise machining and re-torquing.
  • Solid copper or aluminum – Specialty applications, usually with sealing rings.

For modern high-performance street and race engines, MLS gaskets dominate. Cometic and Fel-Pro both offer MLS designs, along with other materials. Let’s examine each brand in detail.

Cometic Head Gaskets – The Performance Leader

Cometic Gasket Inc. is widely regarded as a top-tier manufacturer for racing and extreme-performance applications. Based in the United States, they specialize in multi-layer steel gaskets with proprietary coatings. Their product line covers everything from mild street builds to 2,000+ horsepower drag racing engines.

Construction and Materials

Cometic MLS gaskets are made from 0.008-to-0.030-inch thick layers of spring-tempered stainless steel. Each layer is coated with a Viton (fluoroelastomer) sealing layer that fills microscopic imperfections in the cylinder head and block surfaces. This coating also resists oil and coolant degradation. The number of layers (usually 3 to 5) determines the compressed thickness, which directly affects compression ratio and piston-to-valve clearance.

  • Custom thickness options: Cometic offers over 50 standard thicknesses from 0.027″ to 0.120″. This allows fine-tuning of quench height and compression ratio.
  • Bore sizes: Available for almost any engine, with custom bore diameters to match oversized cylinders.
  • Integral fire rings: Many Cometic gaskets include embossed fire rings (raised rings around each cylinder bore) to concentrate clamping force for a superior combustion seal.

Advantages

  • Unmatched blowout resistance: The multi-layer design and high-strength steel withstand extreme cylinder pressures from nitrous, turbocharging, or supercharging.
  • Reusability: Properly installed Cometic MLS gaskets can often be reused if the engine is disassembled without damaging the coatings.
  • Wide application: From LS swaps to Japanese four-cylinders, Cometic covers nearly every performance engine platform.

Disadvantages

  • Surfaces must be near perfect: MLS gaskets require very flat cylinder head and block surfaces (typically 0.001–0.003″ flatness). Rough or warped surfaces cause leaks.
  • Higher cost: A typical Cometic MLS gasket set for a V8 costs $150–$400+, significantly more than a composite gasket.
  • Not ideal for street-only vehicles: Overkill for a stock daily driver; the cost and surface prep requirements may not be justified.

Real-World Performance

Cometic gaskets are the go-to for many professional engine builders. For example, on high-boost LS engines (20+ psi) or large nitrous shots (300+ HP), Cometic MLS gaskets consistently hold without failure. They are also popular in turbocharged import builds (Honda, Subaru, Mitsubishi) where bore spacing is tight and coolant flow is critical. You’ll find them on many record-breaking street cars and dedicated race engines.

External resource: Cometic Gasket official website for product specs and application guides.

Fel-Pro Head Gaskets – The Reliable Workhorse

Fel-Pro, a brand of Federal-Mogul (now part of Tenneco), has been a household name in gaskets for decades. Their mission is to provide OE-quality and aftermarket sealing solutions for all types of vehicles—from vintage muscle cars to modern trucks. While they offer MLS gaskets in some performance lines, Fel-Pro is best known for their PermaTorque and Performance MLS head gaskets.

Construction and Materials

Fel-Pro’s head gaskets span several material types:

  • PermaTorque (graphite composite): A graphite facing on a steel core, with a rubber seal around coolant and oil passages. Designed to be a “no-retorque” gasket that conforms to surface irregularities.
  • Performance MLS (multi-layer steel): Made from two or three layers of steel with elastomeric coatings. Used in Fel-Pro’s head gasket sets for forced induction and high-compression applications.
  • Race Series: A limited line of solid copper gaskets for extreme racing.

Fel-Pro’s MLS gaskets are similar in concept to Cometic, but they use a different coating and layer thickness. They also offer unique features such as PermaTorque Blue Stripe (visual indicator for proper compression) and pre-applied sealant on critical areas.

Advantages

  • Proven reliability: Millions of Fel-Pro gaskets are used in OEM and aftermarket applications. They are trusted by professional mechanics and backyard builders alike.
  • Affordable: A Fel-Pro PermaTorque composite gasket can cost as little as $30–$60 for a four-cylinder, while their MLS gaskets are usually $100–$200—less than Cometic.
  • Wide availability: Available at virtually every auto parts store (AutoZone, O’Reilly, etc.) with overnight delivery options.
  • Forgiving of surface imperfections: The composite PermaTorque design allows for slight block or head warpage without leaking—good for older engines with less-than-perfect surfaces.

Disadvantages

  • Not for extreme boost or nitrous: Composite gaskets have a lower blowout threshold. Fel-Pro’s MLS gaskets are better but not as robust as Cometic’s thickest offerings.
  • Limited thickness options: Fel-Pro offers fewer thickness choices compared to Cometic, which can limit fine-tuning of compression ratio.
  • Reusability: Composite gaskets deform on installation and cannot be reused. Some Fel-Pro MLS gaskets can be reused, but it’s not recommended.

Real-World Performance

For a moderate street build—say a 350 Chevy with a mild cam and 9.5:1 compression—a Fel-Pro PermaTorque gasket is more than adequate and offers great value. Many enthusiasts have used Fel-Pro MLS gaskets on supercharged small-block Fords and LS engines up to 10–12 psi without issues. They are also a common choice for DIY engine rebuilds where cost and ease of installation are priorities.

External resource: Fel-Pro official website for product lines and installation guides.

Multi-Layer Steel (MLS) Head Gaskets – Beyond Brands

While Cometic and Fel-Pro both manufacture MLS gaskets, the term “MLS” is often used generically to refer to any multi-layer steel gasket, including those from other manufacturers like Victor Reinz, Mahle, and OEM suppliers. In this section, we compare MLS as a category against composite and copper, and discuss what makes generic MLS gaskets different from the branded ones.

Generic MLS vs. Branded MLS

Many aftermarket companies sell MLS gaskets that are sourced from large manufacturers. These can be perfectly adequate for stock or mildly built engines, but they may lack advanced features like custom fire ring designs, multiple thickness options, or specialized coatings. For example, a generic MLS gasket from a local parts store may have only two layers with a simple rubber coating, whereas Cometic’s MLS uses three to five layers with Viton coating.

  • OEM-style MLS: Common in late-model engines (e.g., GM LS, Ford Modular, Subaru EJ). These are engineered for factory boost levels and can handle moderate performance upgrades.
  • Aftermarket generic MLS: Often more affordable than premium brands but with less consistency in quality and thickness. May be suitable for budget builds.
  • Premium MLS (Cometic, Fel-Pro, Victor Reinz Performance): Designed for high-pressure applications with tighter tolerances and better material science.

Advantages of MLS (Regardless of Brand)

  • Strength: Steel layers can withstand extreme clamping loads and thermal cycling without crushing or blowing out.
  • Consistent thickness: MLS gaskets maintain their compressed thickness better than composite, allowing precise quench control.
  • Less prone to creep: Composite gaskets can deform under high heat, causing loss of torque on head bolts. MLS resists this.

Disadvantages

  • Requires perfectly flat surfaces: Any warpage or scratch can lead to leaks. Resurfacing is often mandatory.
  • Higher cost: Even generic MLS gaskets cost more than composite equivalents.
  • Installation precision: Requires careful torque sequence and torquing to spec; no room for error.

External resource: EngineLabs article on MLS gaskets for technical details.

Head-to-Head Comparison: Cometic vs. Fel-Pro vs. Generic MLS

To help you decide, here’s a side-by-side breakdown based on key factors:

FactorCometicFel-ProGeneric MLS
Maximum boost pressure30+ psi (depending on bore size)15–20 psi (PermaTorque); 25+ with MLS10–15 psi (low-end); 20+ with quality ones
Surface prep requiredVery high (0.001″ flatness)Moderate (composite); high (MLS)High
Thickness options50+3–5 (MLS); 2–3 composite1–3
Price range (per gasket, V8)$150–$400$40–$200$50–$150
ReusabilityPossible (careful removal)Not recommended (composite); possible with MLSRarely possible
Best forRace, high-boost, nitrousDaily driver, mild performance, budget buildStock replacement, small upgrades

As the table shows, Cometic excels in extreme performance but demands meticulous preparation and budget. Fel-Pro offers a balanced approach for most street and mild forced induction setups. Generic MLS gaskets occupy a middle ground, but quality varies greatly—stick with well-known brands if you need reliability.

Factors to Consider When Choosing a Head Gasket

Beyond brand, your specific engine application will dictate the best choice. Here are critical factors:

Engine Type and Boost Level

Naturally aspirated engines with compression ratios under 10.5:1 can use composite gaskets like Fel-Pro PermaTorque. High-compression (11+:1) or forced induction (boost over 10 psi) requires MLS. For boost over 25 psi, Cometic’s thicker MLS or custom copper gaskets with O-ringing may be necessary.

Surface Finish and Flatness

MLS gaskets require a surface finish of 50–70 RA (roughness average) and flatness within 0.001″ over 6 inches. If your block or head has warpage, a composite gasket (which fills gaps) might be a better option unless you resurface. Always check with a machinist before installing MLS.

Engine Cooling System

Some MLS gaskets have smaller coolant openings to improve flow in high-horsepower engines. Cometic offers different coolant hole sizes; Fel-Pro sticks to stock dimensions. If you have a modified cooling system (e.g., restrictors, electric water pump), consider a gasket that matches your flow strategy.

Head Stud vs. Head Bolt Torque

Head studs provide more consistent clamping force and allow higher torque values, which is beneficial for MLS gaskets. If using bolts, ensure they are ARP or equivalent and follow a proper torque sequence. Over-torquing can crush an MLS gasket, especially thin ones.

Intended Use – Street or Race

For a daily driver that sees occasional hard runs, a Fel-Pro MLS gasket is a smart choice. For a drag car or road race engine that is torn down frequently, Cometic’s reusability and thickness tuning make it worth the investment. For a budget rebuild, a composite gasket is fine as long as you don’t push boost above 6–8 psi.

Installation Tips for Maximum Head Gasket Performance

No matter which gasket you choose, proper installation is non-negotiable. Follow these guidelines:

  1. Inspect and machine surfaces: Have the block deck and cylinder head checked for flatness and resurfaced if needed. For MLS, aim for a clean, smooth finish—no deep scratches.
  2. Clean all threads: Chase head bolt or stud threads in the block. Use rethread dies for bolts. Lubricate threads and under-head areas per fastener specifications.
  3. Use a torque wrench (plus angle gauge): Many modern engines require torque-to-yield (TTY) bolts, which need a specific angle. MLS gaskets often require a specific final torque value. Do not guess.
  4. Check piston-to-valve clearance: If using a thinner head gasket to raise compression, ensure valves do not contact pistons, especially with high-lift cams.
  5. Retorque after heat cycle (if specified): Some composite gaskets require retorquing after the engine reaches operating temperature. MLS gaskets generally do not, but always follow manufacturer instructions.
  6. Apply sealant sparingly: Many MLS gaskets are pre-coated; additional sealant can cause leaks. Use only on specific areas recommended by the manufacturer (e.g., coolant passage edges).

Conclusion – Which Head Gasket Brand Is Best for You?

The answer depends on your power goals and budget. For extreme performance applications—turbocharged engines over 20 psi, large nitrous shots, or dedicated race cars—Cometic MLS gaskets offer unparalleled strength, customization, and reusability. They are the gold standard for serious builders who understand the importance of surface prep.

For the vast majority of street and mild performance engines (including everyday drivers with bolt-on modifications), Fel-Pro MLS or PermaTorque gaskets provide excellent reliability at a reasonable cost. They are readily available, forgiving of minor surface issues, and trusted by millions of mechanics.

If you are on a tight budget and only need a basic replacement for a stock engine, a generic MLS gasket can work, but we recommend spending a little extra for a known brand to avoid premature failure. When in doubt, consult your engine builder or a reputable parts specialist.

External resource: Summit Racing head gasket selection for pricing and application data.

Remember, a head gasket is a small component with a huge responsibility. Invest in quality, follow proper installation procedures, and your engine will reward you with reliable power for years to come.