Routing all those return lines off the fuel filter seems like too many potential failure points. The filter itself is nothing special so I’m just going to remove it as I already have a separate filter.
I need a way to mount the heat exchanger. The assembly instructions have no advice for this. There are no pictures of it mounted anywhere, so I spoke with Dan at aquamarine. It seems that generally this may get mounted off engine with a pair of blocks he will send me. He had them dropped off at my boat so I drove up to the boat. They are nothing but some v shaped plastic that the are zip tied to the exchanger. I neither like the blocks, and like the idea of mounting the exchanger off engine even less. So, I’ve mocked up a possible mounting bracket with some scrap wood and hot glue.
This was not too terrible design for a first shot at the problem. I’ve fabricated it out of 304 stainless. Even with argon shielding my welder was giving problems. I think the polarity may be failing, but I as able to get good penetration even though the welds themselves were pooling excessively. It looks so so, but should be plenty strong enough.
Here is the heat exchanger sitting on top of the fabricated mount with the fittings and hoses in place. It actually fits rather nicely.