New Head Gasket choices for the 928
#1
Developer
Thread Starter
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I have never really happy with the head gasket choices I had to work with.... either having to use the stock head gasket (designed more than 30 years ago and lacking any updates to materials or the composite structure) or use the MLS headgasket that came along a few years ago.
But few engines have the dead-flat decks and heads needed to make a MLS head gasket seal, and the retourqing of the heads after 3 heat cycles is no fun on the 32v motor.
I shipped a 928 block to a major gasket manufacturer, and commisioned the pattern making of the 928 head gasket so now we can offer you more choices, updated materials, and updated composites.
Here is the overview:
Engines, naturally aspirated and up to 10 psi of boost, without o-rings.
Heads and block do not need to be decked unless severely warped.
Some corrosion pitting OK depending on location.
Re-torquing the head gaskets will not be necessary.
Excellent replacement for stock head gaskets with better sealing properties.
Use GCS (Graphite-Composite Steel)
http://www.928motorsports.com/parts/...el_gaskets.php
Engines, naturally aspirated and up to 20 psi of boost, with o-rings.
Heads and block do not need to be decked unless severely warped.
Some corrosion pitting OK depending on location.
Re-torquing the head gaskets after 2-3 heat cycles required.
Recommended when non-stretch aftermarket head studs are used.
Best thermal transfer properties for cooling the heads (Turbos)
Excellent for lowering Compression Ratio, available in thicker sizes.
Use SCC (Silicone-Coated Copper)
http://www.928motorsports.com/parts/...ad_gaskets.php
Engines, naturally aspirated and up to 30 psi of boost, without o-rings.
Heads and block must be decked. No corrosion pitting tolerated.
Re-torquing the head gaskets after 2-3 heat cycles required.
Best when used on fresh complete engine builds, after decking block.
Can be special ordered in thicker sizes at higher custom cost.
Use MLS (Multi-Layer Steel)
http://www.928motorsports.com/parts/headgaskets.php
But few engines have the dead-flat decks and heads needed to make a MLS head gasket seal, and the retourqing of the heads after 3 heat cycles is no fun on the 32v motor.
I shipped a 928 block to a major gasket manufacturer, and commisioned the pattern making of the 928 head gasket so now we can offer you more choices, updated materials, and updated composites.
Here is the overview:
Head Gasket Selection Table
Engines, naturally aspirated and up to 10 psi of boost, without o-rings.
Heads and block do not need to be decked unless severely warped.
Some corrosion pitting OK depending on location.
Re-torquing the head gaskets will not be necessary.
Excellent replacement for stock head gaskets with better sealing properties.
Use GCS (Graphite-Composite Steel)
http://www.928motorsports.com/parts/...el_gaskets.php
Engines, naturally aspirated and up to 20 psi of boost, with o-rings.
Heads and block do not need to be decked unless severely warped.
Some corrosion pitting OK depending on location.
Re-torquing the head gaskets after 2-3 heat cycles required.
Recommended when non-stretch aftermarket head studs are used.
Best thermal transfer properties for cooling the heads (Turbos)
Excellent for lowering Compression Ratio, available in thicker sizes.
Use SCC (Silicone-Coated Copper)
http://www.928motorsports.com/parts/...ad_gaskets.php
Engines, naturally aspirated and up to 30 psi of boost, without o-rings.
Heads and block must be decked. No corrosion pitting tolerated.
Re-torquing the head gaskets after 2-3 heat cycles required.
Best when used on fresh complete engine builds, after decking block.
Can be special ordered in thicker sizes at higher custom cost.
Use MLS (Multi-Layer Steel)
http://www.928motorsports.com/parts/headgaskets.php
#2
Developer
Thread Starter
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The Graphite-Composite Steel Gasket: These gaskets are special in several ways. Start with the high density/expanded graphite composite material mechanically bonded to a perforated steelcore. Add stainless steel fire rings that capture a copper core inside them, and add the fully encapsulated silicone coating that helps seal any gasket surface flaws or imperfections.
The bottom line: tougher fire rings, and better gasket sealing in all situations.
No O-rings Required: These head gaskets do not require O-rings and cannot be used with O-rings. The stainless steel armor/combustion seal w/contained copper wire rings is especially good at sealing low-boost assisted applications.
Sizes Available: This auction is for 100mm bore head-gaskets as used on all 5.0L 928s. We can also make them for 4.5L engines with 95mm bores and 4.7L engines with 97mm bores on special order. Thickness is 0.065"
The bottom line: tougher fire rings, and better gasket sealing in all situations.
No O-rings Required: These head gaskets do not require O-rings and cannot be used with O-rings. The stainless steel armor/combustion seal w/contained copper wire rings is especially good at sealing low-boost assisted applications.
Sizes Available: This auction is for 100mm bore head-gaskets as used on all 5.0L 928s. We can also make them for 4.5L engines with 95mm bores and 4.7L engines with 97mm bores on special order. Thickness is 0.065"
#3
Developer
Thread Starter
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Copper Head Gaskets are well-known for their sealing capability on slightly less-than-perfect decks, and racers like both the high thermal conduction of the copper and the fact that the expansion/contraction properties of the copper can mimic that of the aluminum block and heads where steel gaskets will not.
No gasket will conduct high heat around exhaust valves into the block and water jackets as fast. Great for Turbos.
Copper Head Gaskets are especially useful when using non-stretch type engine head studs, like after-market hi-performance hardware.
O-rings Required: Copper head gaskets require the use of cylinder o-rings to replace the absence of a fire ring on the gasket. The o-rings can be machined into either your heads or your block. O-rings are commonly 0.040" stainless steel wire, and that works well with these.
Sizes Available: Available in 100mm bore for 5.0L engines, 95mm bore for 4.5L engines, and 97mm bore for 4.7L engines. Thicknesses from 0.40" to 0.65" are available, select yours below.
No gasket will conduct high heat around exhaust valves into the block and water jackets as fast. Great for Turbos.
Copper Head Gaskets are especially useful when using non-stretch type engine head studs, like after-market hi-performance hardware.
O-rings Required: Copper head gaskets require the use of cylinder o-rings to replace the absence of a fire ring on the gasket. The o-rings can be machined into either your heads or your block. O-rings are commonly 0.040" stainless steel wire, and that works well with these.
Sizes Available: Available in 100mm bore for 5.0L engines, 95mm bore for 4.5L engines, and 97mm bore for 4.7L engines. Thicknesses from 0.40" to 0.65" are available, select yours below.
#4
Developer
Thread Starter
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No matter what your pleasure... Supercharger, Turbo, Nitrous, or Stroker - these Cometic MLS (Multi-Layer Steel) Head Gaskets will keep the lid on things. Made from 3 layers of Stainless Steel and specially embossed around each water and air passageway, our head gaskets will survive where no others will.
Adjustable: The gaskets can be ordered with several different center-section widths - so you can vary your compression ratio or give yourself a little more valve clearance for hi-lift cams. .045" is standard - but the thickness of the gasket can be special ordered all the way up to .120" if needed for your application.
Bores Available: 100 mm, 103 mm, 104 mm, and 106 mm
Adjustable: The gaskets can be ordered with several different center-section widths - so you can vary your compression ratio or give yourself a little more valve clearance for hi-lift cams. .045" is standard - but the thickness of the gasket can be special ordered all the way up to .120" if needed for your application.
Bores Available: 100 mm, 103 mm, 104 mm, and 106 mm
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#12
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So if my math is correct, theGCS at .065" thick is 1.651mm thick. Pretty tall compared to stock. Actually a good thing for my application. I going to recalculate my static C/R using this thicker head gasket, but I think we've got a contender.