Performance Diesel and Performance Gas machine shop   Custom oversize valves available for Cummins, Duramax, & Powerstroke
Cylinder head and/or block surfaces can be modified for improved combustion chamber sealing. This can be performed on nearly any cylinder head or block to create a seal capable of withstanding increased combustion pressure, temperature, and corrosion found in a performance engine combustion chamber.  The two popular methods we recommend are:

1.Fire Ringingfor improved combustion chamber sealing

2."O" Ringing for improved combustion chamber sealing
       5293 Ward Road, Unit #3      Arvada, CO   80002     303-420-6218
The ultimate sealing system for all out performance engines.  The view on the left is a big valve modified 5.9L cylinder head with CNC machined Fire Ring Grooves.  The view to the right shows a block with CNC machined receiver grooves to compliment the cylinder head profile.  The groove can also be cut into the head only, eliminating the need of block removal from the vehicle.   This process requires a modified head gasket that allows the fire ring to contact both the head and block, eliminating any gasket exposure to engine combustion.  We do not normally recommend this system unless the engine is going to be disassembled regularly for inspection and expendable part replacement, as is typical in any race engine. 
CNC Machined Fire Ring Grooves:


Bridgeport flycutting "O" Ring Grooves:
For years the standard in combustion sealing for performance engines has been the "O" Ring process.  This is still a very good enhancement to stock or performance cylinder heads.  Differing from "Fire Rings", the "O" Ring uses a stock or modified head gasket and contacts the gasket itself to produce increased head gasket crush pressure to insure combustion sealing in a performance engine.  This process is normally performed to either the block or the cylinder head.   We typically use a .041" stainless steel wire to create the "O" Ring in any necessary diameter, although many gauges and materials are available for the wire itself.