You are in luck... that may be possible.... for one thing diesels run much cooler than that Rotary....
But you may also be able to use a Silicone ... I have seen them available with heat resistance which would allow casting Bronze into them... and them still be flexible to take bend off the item and reused...
But in general I never recommend JUST epoxy for anything... if you use it I would suggest backing it with something like thin brass sheet ( I use brass 10 thousandths shim stock )... much stronger and it gives uniform support when placing the epoxy....
On an exhaust you can use a screw type hose clamp to hold the brass in place... but remember to leave the epoxy as thick as reasonably possible...
Like many jobs.. cleanlyness is very important.... and do not start engine or touch it for at least 24 hours from placement....