Bi-Metal Head Gaskets

We have the facilities for in-house manufacture of our own design Bi-Metal head gaskets, as one-offs, or in small batches, and have been making these since around 2006. Over the years, they have found their way into some amazing applications, have succeeded where other types of gasket have failed 🙂 and have occasionally been incompatible with some engine designs 🙁 So, although they can be applied to almost any engine, they may or may not be the correct choice. Keep reading, and further along we’ll look at how to decide if these are for you.

The idea for the Bi-Metal came years ago when we were machining and building competition engines, but found that we often couldn’t buy a suitable head gasket – maybe because of geometry, maybe because of strength issues. So, after a lot of experimentation a formula was decided, and this formula can be applied to almost any engine.

We immediately found that correct engine machining is essential (a surface finish similar to or exceeding the requirements of a Multi Layer Steel gasket to both block and head), you can’t get away with much as these gaskets are made from solid metals. To elaborate, our sealing ring is made from solid copper, and although copper is a very soft metal, it’s a seriously hard gasket material that is unlikely to conform between irregular surfaces.

Here’s a brief run-down of some different types of head gaskets and their characteristics –
– Copper/Asbestos/Copper (or Steel) sandwich – lovely and soft, very easy to seal but quite weak.
– Steel Tanged Graphite – a good mid-point gasket, easy to seal but with reasonable strength.
– Multi Layer Steel – currently used in almost every production engine, slightly more difficult to seal but capable of coping with almost anything, including modern high performance diesels.
– Ferriday Bi-Metal – more difficult to seal, not necessarily compatible with all engines, but incredibly strong once proven, only to be used once there are no other options.
– Solid Copper – seriously difficult to seal (often requiring all water passage between block and head to be routed externally) but strong enough to cope with Dragster level power outputs, to be avoided at street level.

If you need an alternative head gasket because of the extra power developed by your modified engine, our advice is to first look at your clamping system. Companies like ARP specialise in bolt or stud & nut systems that will be an improvement over OE. Next, have a look at Multi Layer Steel gaskets – even if your engine had an earlier design of gasket, companies like Cometic may now make a MLS gasket for your application.

If your OE gasket no longer fits because of increased bore diameter, look for a MLS gasket that has a larger bore aperture.

If your head gasket is too thin, have a look here for Decompression Plates, or here for MLS modifications.

And if none of the above helps you, please contact Mick Tanski on 07915 719 242, or micktanski@gmail.com and we can talk about Bi-Metal head gaskets.

Here’s a link to the info sheet that describes the Bi-Metal gasket further.

All materials & tooling used in the manufacture of these products come from ISO9001/9002 suppliers, and all Ferriday Engineering products are made entirely in-house using current-technology CNC machinery.