It's a very special and expensive one.. I think I cannot reveal my secrets


Oh well OK, I will share my technique. When I have to bend a pipe like this I start going around my workshop or even my home.
When I find something with the correct diameter I stop. Go back to the engine and see if the diameter is fine regarding to what I want to make.
Then I grab the copper pipe, turn it around the object I have found, cut the ends with the trial and error method, maybe some more free bending by hands and that's all.
Then soldering and straight to the platter.
I also destroyed a piece of pipe trying to make this fuel line as the last time I made one was some time ago.