Exhaust Manifold Copper Gasket Cross Section

[Andy Clap]

So, the copper gasket rings I've been supplied are round in section, whereas the ones which have come out are flat.  Also the new ones are about 2mm smaller in diameter.


Anybody fitted the same, and does it matter?


Cheers.

[Graham53]

If memory serves me the copper gasket washers are compresssion type and squash down and would be flatter and bigger when they come out.
When you put the new ones in smear a bit of grease over the face to the engine it helps them to stay in place when you fit the downpipes and torque the nuts up to correct tightness

[Fazerider]

I've noticed that too.
And a similar thing happens with tyres: smaller diameter with a flat portion to the profile, but the new ones are bigger with a round profile.
I'm baffled.

[darrsi]

I've noticed that too.
And a similar thing happens with tyres: smaller diameter with a flat portion to the profile, but the new ones are bigger with a round profile.
I'm baffled.

 

[Andy Clap]

If memory serves me the copper gasket washers are compresssion type and squash down and would be flatter and bigger when they come out.
When you put the new ones in smear a bit of grease over the face to the engine it helps them to stay in place when you fit the downpipes and torque the nuts up to correct tightness

Brill, many thanks 

[darrsi]

Just make sure you clean all the old crud and debris before putting the new ones back in so that they seat properly, and as said a nice blob of grease helps keep them in place too.


When i changed my exhaust when i bought the bike the previous owner had put new gaskets on top of the old ones.

[tommyardin]

If memory serves me the copper gasket washers are compresssion type and squash down and would be flatter and bigger when they come out.
When you put the new ones in smear a bit of grease over the face to the engine it helps them to stay in place when you fit the downpipes and torque the nuts up to correct tightness

Exactly they are indeed meant to compress, I have heard that they are sometimes known as crush Gaskets, when they crush or compress they expand.
The gaskets I got with my S/S down pipes were round in profile and had to dab some grease on them to hold them in plase while I lined the down pipes, They have certainly never leaked at the manifold.

[Andy Clap]

  Many thanks all