3 hours.
Came home from work and tucked into the baffles. This setup is basically a box of aluminum that goes around the engine, forcing the air from the cowling intakes down through the cylinders to cool the engine. It was so nice to get back into metal work, after months and months of wiring, but it wasn’t without difficulty.
The plans have you start on the aft left baffle, which is where the oil cooler mounts. You have to cut a rectangular hole in the aftmost outer piece to accommodate the airflow though the cooler and a doubler that supposedly reinforces it against the stresses of having a big chunk of aluminum bolted to it.
The plans say to mount this doubler 3/8″ inboard of the edge and as high as you can for greater airflow efficiency. 3/8″ is a lie. If you do that, you don’t have enough edge distance between the edge of the hole and the angle of the part that attaches to the #4 cylinder, and that’s bad. So do 5/16″. Unfortunately, I have a couple of exploratory holes in the baffle trying to get this right. It’s a little uglier than I’d like, but I’m not trying to win any beauty contests with the baffles. If everything goes right, you’ll never see them.
This shot shows the baffle on the bench being match-drilled
Looks like I’m going to have to cut away another 1/4″ of metal on the left side there to clear the airflow to the cooler.
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