I was hoping I might get some help with a project I am working on. I am building a GP Christen Eagle and am placing a US Engines 41 on the nose. I have been reading a lot of posts from people flying this plane who have experienced cabine cracking and failure as well as other structural problems from vibration.

For starters I am mounting my engine using a GP large engine isolation mount to reduce vibration and potential problems with that issue. Has anyone else built this plane and done the same and if so what kind or results did you achieve?

The real question I am here for is that I would like to modify the stock muffler and place a spray bar in it for a smoke system. Since the stock muffler has a baffle in it with a screened hole in the center I was unsure where the spray bar would be most effective and the correct location for placement. I know some engines have experienced problems with smoke oil being sprayed into the exhaust port so if the correct place is on the engine side of the baffle I can install a spray bar the does not have holes facing the piston.

If it is better placed on the outboard side of the baffle that is moot but also does anyone know if the internal baffle is needed for proper engine operation? Since only a portion of the muffler receives exhaust gasses due to the baffle and hole cut in it should the spray bar also be restricted to the size of the opening?

I would be happy to post some photos if anyone would like to visually see what I am referring to.

Thanks for any help and input...

Charlie