Head Gaskets and Fire Rings

The stock head gasket for the 6B engine is capable of handling a maximum of 40 to 45 pounds of boost before the head gasket becomes the weak link and is likely to fail.  Many daily driver street trucks are exceeding this amount of boost with tuning to the stock turbo,  and as a result we get frequent calls with questions about the fire ringing process.  Fire rings are taken from tractor pulling, where high turbo boost pressure has been commonplace for many years.  Keating Machine began offering fire ring installation for street applications in the late 1990’s and has performed the machining services in-house since 2000.  Proper installation of fire rings will accommodate increased turbo boost levels.  On Keating Machine drag racing applications, we have run 140-160 pounds of boost and commonly see 100 pounds in daily driver applications.  Installation of fire rings assures a strong seal between block and head – so much so that we have seen block failure before fire ring/head gasket failure in high boost racing applications. 

Installation of fire rings requires that either the head or the block are machined to accommodate the rings. While some may recommend machining both surfaces, we here at Keating Machine feel that machining one surface allows for movement of the head on the block to accommodate the shrink/swell of the two pieces as heat builds and dissipates in the different parts.  In addition to machining the head or block, we modify a stock head gasket by cutting out the sealing rings to allow for the fire ring installation.  The fire ring used by Keating Machine is made from .105” thick wire with a 4.25” ID.  The ring groove is machined to .030” deep with a 4.49” outside diameter and 4.22” inside diameter to accommodate the fire ring.  By overcutting the groove, it allows for the crush/distortion of the fire ring when the head is torqued to the block.  Our success with fire ringing 6B applications has been overwhelming.If you are serious about running high boost pressure, you need to consider having fire rings installed.  Have more questions about this or any other technical issue, give us a call or send us an e-mail.