After reading a lot I didn’t find so much about epoxy adhesives
Particularly adhesives for carbon fiber epoxy matrix to glue parts together with high temperature resistance , chemical resistance (oil,fuel,ethanol) and very strong bond and non flammable … A lot of demands. 
Somebody maybe know this kind of product?
Just some data of divers adhesives and the max temperature resistance was around the 200 F
Maybe is it better to use the same matrix with fillers to create bonds between parts made with the same epoxy ? Then which fillers would you recommend to use ?
I think that if it is possible this way then we can post cure parts who are already bond together and require high temperature post cure…?
What about 3Ms epoxy DP760 for a high temp application up to about 230C
http://www.vikingindustrial.co.uk/pdf/epx.pdf
Cant say I know much about the chemical resistance of this range but a quick phonecall would find out. Having used the DP410, 460 and 490 before, I can confidently say it is a good product range!
Also Huntsman are supposed to be vgood but I havent used them as Ive been hapy with all 3M stuff Ive used.
https://www.huntsmanservice.com/Product_Finder/ui/search.do for the product finder but that search function seems a bit crappy. Worth ringing the Americas office and asking maybe about LNG Adhesives (saw that on their website, Im guessing that is Liquid Natural Gas industry adhesives which sound perfect for your application).
Keep in mind that whoever you call, they will ask for the chemicals it should be resistant to, at what temperature, what temperature resistance, what type of loading (dynamic or static).
About fire retardancy: fillers (which retard fire) will make the glue more brittle, but epoxy in itself does not ADD to the fire. Perhaps that is already enough?
Thank you
I will do more research about 3M and huntsman
Also I see that some people use the same epoxy that they made the parts with and add divers fillers to use it as adhesives to bond the parts together
Is it better way than to use adhesive ?
In general premade adhesives are stronger than home made brews.