I finally found some stuff come to find out my brother makes this stuff at his shop it is for extreme temperatures there is think and not so thick stuff attached are a few pictures of the stuff I'm using now on the exhaust It seems to help cut down on vibration this stuff works great
Specific Gravity: 1.5
Shelf Life: Much longer than asbestos sheet
Temperature Limit: 750°F* (399°C)
Pressure: 1400 psi (99 BAR) @ 750°F
Sealability: 0,7 ml/hr
Chloride Content: 100 ppm max
Compressibility: 7 – 17% (ASTM F-36A)
Recovery: 50% (Minimum)
*Typical values derived from tests performed using 1/16" thick material
It is very very smooth on one side feels like rigid rubberized cloth -without the elasticity is the only way I can think to describe it. I will try to find out more info.
It is used to seal in toxic chemicals and hi pressure steam they use it where ever there is joint
"no not that joint" . What temp do these bikes reach? 700° on a bad day?
If it's hi-temp gasket material for industrial application than probably nomex fiber/nitrile like garlock blue gard or palmetto supersheet. Your lucky if you you can get small pieces from your bro because both are expensive and hard to get in small sheets.