Many shops use the easy – and quick – method of machining the O-ring groove in the block, with readily available tools that pilot off the cylinder.  In some cases, that works fine.  But, over the years, we have seen this method damage cylinder heads.  While the damage was not severe, or epidemic, it was enough to make us uncomfortable with the method.  As a result, if O-rings are called for, Total Flow Products will properly machine the O-ring groove only in your cylinder head.  Whether installing O-rings cut from a coil of wire or machined in one piece, grooving the cylinder head is the only method we use.

Total Flow Products offers three O-ring options.  For the basic option, the groove will be machined so the O-ring wire will stand .006” to .008” above the head surface.  Nothing else is required, except a bit of quality sealant (RTV, etc.), on both sides of the head gasket, around the oil and water passage openings.  Care must be taken with the amount of sealant used.  Excessive sealant can block the oil and water passages when the head is installed and tightened down.

If even greater sealing capability is needed, a groove can be machined to stand the wire .012” to .015” above the head surface.  This standing height requires machining a receiver groove in the block or sleeve.  Again, judicial application of sealant is required to the head gasket oil and water passages openings.

For extreme applications, where the O-ring stands .015” or higher above the head surface, a one-piece ring must be machined from stainless steel.  A receiver groove must also be machined into the block and sealant will still be needed for the head gasket oil and water passages.

If you are uncertain about stepping up to O-rings, please call Total Flow Products and describe your application.  We’ll discuss it with you, then recommend O-rings (or not!) and specify an appropriate standing height.  We’ll also advise if a receiver groove is needed and whether wire or machined rings will be required.