alt Hacker NewsI don't know if it is the same in the UK as it is in the US, but the appeal of experimental aviation (every Cozy is experimental) is that there are no specs or requirements around parts like this.
If you want to slap 15 weed-wacker engines to a wing you made from styrofoam and call it an airplane, the FAA will not stop you.
I'm oversimplifying, a bit, but less than non-pilots might think.
In other words, the engine maker probably has some thoughts about how that piece should be made, but the FAA would have no problem with you installing it on an experimental.
My understanding of the UK CAA is that it isn’t as liberal as the US FAA when it comes to amateur-built experimental aircraft airworthiness. I would still be surprised if a 3d-printed intake manifold on a homebuilt passed an airworthiness inspection in the US without a number of detailed questions being answered to the satisfaction of the airworthiness representative.