Fire Ringed Heads

Fire Ringing the Cylinder Heads for a Maximum Seal



Fire Ring Cylinder Heads Diesels engines are high compression machines, and cylinder pressure can get dangerously high in performance applications and cause the cylinder head to lift, resulting in head gasket failures. While headstuds are adequate for preventing this in most cases, performance engines that experience high boost pressures and lots of fueling may need to be fire ringed to ensure proper seal. Fire ringing should be considered if you are building a high performance drag truck or sled puller that needs to be able to withstand anything you can throw at it.


Otherwise Known As:

fire rings, fire ringed heads

How It Works:

Fire ringing your cylinder heads requires sending them to a professional machinist. Cylinder heads are surfaced to ensure they are flat, then a small groove is cut around each combustion chamber. A metal o-ring is inserted into this groove. When the heads are reinstalled, the o-ring seals so the engine block, and the head gasket seals around the o-ring. A stronger, aftermarket head gasket is typically used, and replacing the factory head bolts with head studs is required. This provides a much stronger seal than a head gasket alone and ensures leak-free performance in even the most extreme situations.


• Prevents head gasket failures and cylinder head lift in high performance applications.
• Leak free seal.


• Requires machining and cylinder head removal.
• Requires head studs.

Possible Problems:

It is important to have your cylinder heads measured and surfaced if necessary. They must be flat to ensure a good seal.

Est. Gains:

Peace of mind.


All Power Stroke, Cummins, & Duramax engines.

Additional Info:

For those who do not wan't to deal with shipping their heads to a machinist, many companies offer complete replacement cylinder heads that have been fire ringed. This modification is well worth the investment if you are considering high boost pressures and large volumes of fuel.


Fire Ring Heads


This is a cylinder head that has been fire ringed. The machined groove is shown by the red arrows. A metal o-ring fits into this groove, which seals to the engine block when the cylinder head is reinstalled.


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