NC Header "Donut" Gasket

DESCRIPTION

Replacement factory Mazda "donut" style gasket for the junction between header and midpipe on 2006-2015 NC MX5.

If you have a leak at this junction, replacing the gasket might be the fix.

Note this will not stop condensation weep at this joint. It's a moving joint, metal on one side, condensation passing through that sort of flex joint is going to happen and we see it on these cars brand new from the dealership. But if you feel 'puff puff puff' actual exhaust gases leaking then consider a replacement. This is a GENUINE MAZDA factory part, not a cheap copy, we import these direct from Mazda Japan. This is a wear item, they will not last forever, mere soft graphite pressed into the metal mesh and the graphite slowly wears away as the joint moves.

Brian's Notes: Think of this gasket style as rather like a number 2 pencil, as the round side of it rubs into the new home in the 'mouth' of the midpipe it builds a transfer layer. The springs push it into that midpipe mouth and as you drive the engine wags it back and forth in hundreds of little micro movements per mile. That process builds up more and more of the graphite as a transfer layer in the mouth of the midpipe. This style of gasket never gets water tight, it will always drip condensation at that joint, but it will seal better and better with some miles as the transfer layer is built up. I recall Summit Racing had a chart on sealing properties of header gasket materials, rating this style of graphite impregnated matrix just 3 out of 5 for sealing properties. But the advantage is that it can be used in a dry flex joint to help reduce the impact of engine movements wagging the entire exhaust system.