More Progress On Exhaust System

Initial try, wood block represented the (theoretical) cross section of the carb heat stove.
Unfortunately I forgot to account for the pushrod tubes. So the carb heat stove had to get substantially slimmer, and the the 180 degree bends got "clocked" vis-a-vis the exhaust flanges a little bit. I'm using hot melt to hold the bends to the exhaust flanges. It works great, it holds securely enough to get everything jigged up, and breaks lose if you make a boo-boo (the oil on the tubing helps this).

I forget where I stole this idea but it works great! The welder (not me, I'm not currently set up for it) can tack the butts in between the 3 coat hanger wires.

Ready to send to the welder.
Note the stainless steel pot scrubbers to add heat transfer surface. This entire mess gets wrapped with aluminum sheet, with a flanged connection for the duct to the heat box. Not shown in any of these views is the solid aluminum spacer that gets clamped in between the pipes to hold everything nice and solid. I didn't like how the pipes were cantilevered off the exhaust flanges.

This was a pretty easy and satisfying project. I made all the tubing cuts with a hacksaw, cleaning them up with my disk sander.

The next question is whether to make the other side identical to this, or to go as simple/light as possible, or to join the pipes to facilitate a muffler. I've flipped the engine over in the stand, and I'll stare at it for a few weeks - something will come to me. Also, the plumbing of the hot air to the carb heat box is a little unclear. The bed mounts REALLY get in the way of where I'd like to route this tubing. Hopefully once the intake starts coming together that will be a little clearer