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Product Summary

Dead Soft Copper Gasket Material, Copper

  • ThermoTight dead soft copper gasket material is .040-inch thick and seals headers or manifolds by conforming to their surfaces
  • Copper header gaskets are reusable, making them the perfect solution for performance engines that often see teardown
  • Will not turn brittle, burn up, shrink, or blow out like common paper/fiber exhaust gaskets on the market
  • Copper exhaust gaskets are preferred for high heat applications like turbochargers and high rpm use
  • Sold as a set of six for Flathead V8 ('32-'53 Ford car or truck applications)
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Key Specs

MFG. Part #91013599
BrandSpeedway Motors
Gasket MaterialDead Soft Copper
Overall Thickness.040"
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Need To Know

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Return Policy

Speedway Motors 91013599 Details

  • Cut from .040-inch thick dead soft copper sheet material
  • Reusable copper header gaskets provide ultimate sealing, even on irregular surfaces
  • Raised ridge port seal enhances sealing and prevents blow outs
  • Natural high temperature use that will not burn or deteriorate like paper gaskets
  • Best gasket option for high performance use, turbo setups, and more
  • 1.625-inch inside diameter and 2.875-inch center to center bolt spacing
  • Complete set of six gaskets to seal most any manifold or header to your Flathead
  • Seals imperfect header and cylinder head surfaces that paper gaskets can’t

Stop Wasting Money on Cheap Paper Exhaust Gaskets

When buying headers for your ride many of the brands you’ll find provide gaskets and header bolts in the box for a complete installation solution. While this is admirable of the manufacturer, often the included header gaskets (and even the bolts at times) are made from subpar materials to keep product costs down while providing this “everything you need in one box” purchase mentality. The truth of the matter is that these paper/fiber header gaskets may help get your headers installed but they certainly will not seal very well or last exceptionally long. The main issue is sealing. Both the headers and even the cylinder head port surface can have irregularities that cause the gasket to not seal and to be easily blown out. Add to that issue that paper based gaskets often can’t handle the intense exhaust heat in some applications and will burn/turn hard, causing leaks as well. The answer? High quality ThermoTight dead soft copper gaskets that form over minor imperfections for a better seal that are also reusable, saving you money overall.

Dead Soft Copper for Superior Sealing and Reusability

Paper and other fiber-based gaskets are not the best materials to use for sealing exhaust systems. Sure, you can slather on a bunch of silicone or other gasket maker to help but that just makes a mess of your engine and headers. What about soaking those paper gaskets in water to expand them for a better seal? Sure, it’s an old hot rodder trick that might help, once! Or the gaskets may completely fall apart on you. No, the best sealing is offered via materials like dead soft copper. Stamped from .040-inch thick dead soft copper gasket material, this malleable material easily conforms to header exhaust port weld beads and other tough sealing issues like gouges or even minor corrosion pitting on the exhaust face of your cylinder heads or headers/manifolds.

The dead soft copper header gaskets maintain their softness and have no annealing properties so the copper exhaust gaskets can be formed repeatedly to maintain the best seal use after use. This makes the ThermoTight copper exhaust gaskets perfect for engines that see a lot of header or manifold removal like race cars, engines that see a lot of tear down like turbo setups, or enthusiasts that like to change headers with under car exhaust to zoomies or outside the frame lake pipe setups on their Flatheads for an event or cruise. The embossed sealing ridge on the copper header gaskets (which always faces the header flange) helps sealing even further by adding additional conformity to the material, while helping to maintain the gaskets reusability and durability.

Overcome High Heat Exhaust Gasket Failures, Blowouts, Leaks, and More

Copper is used in wiring because it is a great conductor, both of electricity and heat. Being a solid thermal conductor, copper makes for an excellent exhaust gasket material. The engine’s exhaust heat at the exhaust face of the cylinder head is quickly and easily transferred to the exhaust header tubing via the copper exhaust gaskets to be carried away from the engine via exhaust flow and radiant air flow around the header tubes. Paper-type gaskets are the exact opposite, as paper is an insulator, holding in those high exhaust temperatures. This insulating effect is what burns the exhaust gasket, turning it brittle and causing leaks and blow outs where gasket coverage is thin. 

Paper gaskets also “set” over time, which is why most manufacturers recommend constant header bolt tightening. The bolts aren’t backing out, the gasket is shrinking/setting, and the bolts require tightening to apply clamping force on the paper gaskets again to maintain proper sealing. With the use of ThermoTight dead soft copper header gaskets you won’t have to worry about header bolts being a maintenance issue, as the copper gasket material does not shrink or blow out like paper gaskets do. You can always add locking header bolts for extra piece of mind as well. ThermoTight copper gaskets work extremely well as copper exhaust manifold gaskets too if you’re having issues sealing original iron exhaust manifolds.

Solve your exhaust gasket sealing problems with our ThermoTight dead soft copper gaskets and put exhaust leaks behind you. Easy to install, reusable, and premium materials at an excellent value that are perfect for high performance engines used in serious street cars or racing and for extensive high heat applications like supercharged or turbocharged builds. What’s not to like?

Speedway Motors 91013599 Specifications

KEY SPECS
MFG. Part #91013599
BrandSpeedway Motors
Gasket MaterialDead Soft Copper
Overall Thickness.040"
GENERAL
Material TypeCopper
Port StyleFord
Inside Diameter1.625"
Centerline of Holes2.875"
Sold in QuantitySet
NotesSold as a six piece set

Ratings & Reviews

4.9

13 Reviews

Overall Assessment

Customers highly appreciate the product for its practicality and usability, specifically fitting perfectly on various models, including a 1949 F3. Users were pleased as the item could be repeatedly used, saving them from scraping off residual material. The quality is rated as top-notch with customers noting their durability, lasting almost forever. The product's material, although thinner than expected, remained usable and efficient. High recommendations came from comparisons to the competition, with our product outshining others, particularly due to its exact fit and reusability.

4.9

13 reviews

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Great product.

5.0

5 months ago

Trkguy

Palm Springs CA

Verified

These sealed a persistent exhaust leak on my flathead Ford.

Would Recommend

Exhaust

5.0

6 months ago

Speedy

Mn

Verified

I like the thinner construction for tight engine bays, nice quality

Would Recommend

Copper gaskets seal

5.0

9 months ago

Carnutt

Pa

Verified

Copper exhaust gaskets work great

Would Recommend

Yes, I would buy thi product again.

5.0

a year ago

Paulie Wog

Northern Ca.

Verified

Used for the headers on my '50 F-1 Ford pickup.

Would Recommend

Just what I was looking for.

5.0

a year ago

Freewheelin

Northern Michigan

Verified

Composite gaskets didn't hold,these along with permatex the right stuff should be final solution 🤞

Fit my 1949 F3

5.0

5 years ago

Nice Ol' Dave

Little Meadows, PA

Verified

I had been looking for a pair of gaskets to go between the exhaust manifold and exhaust pipe flange. I was just on the process of buying exhaust gasket material and making my own when I found these at Speedway. Wasn't sure they would fit but the price was right so i took a chance. Glad I did,because they fit perfect and I now have spares!

Would Recommend

Thinner than I expected...

4.0

5 years ago

Øistein

Norway

Verified

Thinner than I expected, but useable...

Would Recommend

Top Quality Product, from the BEST supplier

5.0

6 years ago

Jeffro

Southern Ohio

Verified

top quality product from the BEST supplier you could ask for

Would Recommend

Great fit and are reusable.

5.0

6 years ago

John

West chester, PA

Verified

Happy to have found one that is reusable. Saves from having to scrape old junk off.

Would Recommend

Exact fit

5.0

6 years ago

Ron Tractor Man

Kokomo Indiana

Verified

Part was what I expected and fit exactly.

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Showing 10 of 13 reviews

Fitment

  • 221 Ford Flathead V8

  • Ford Flathead V8 17 Stud 221 18

  • Ford Flathead V8 21 Stud 221 40

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Customer Impersonation Script