The radiator is still a work in progress but several people have asked me about it so I thought I'd post a few pictures showing what I have to date. As of 5/29/03 the core and tanks are completed and mounted on the plane. I still have to attach the cooling fins. This is going to be a fairly complicated process so I thought I'd just do some ground testing like it is and see what happens.
This pictures shows a test fit of the assembled core. The tubes are TIG welded to the upper and lower tank headers. The 1/4 inch wide tubes are spaced on one inch centers leaving 3/4 inch gap between the tubes. The lower header is simply bent on a metal brake to form the U shape after the holes are cut in using a drill and router. The upper tank is a little more complicated. The arch is hammer formed over an MDF dye. Since each tube intersects the header at a different angle, the spacing between the centerline of the tubes is different for each tube. After working through the geometry to figure the centerline spacing and hole cross sections I used a CAD program lay it all out and print a full size pattern. The pattern was taped to the header to act as a guide for cutting the holes by hand.
This dye was used to form the oval shaped tubes out of round tube. Paper shims are placed under the MDF dies to adjust the thickness of the tube.
This shows the back side of the prop shaft trim ring. The ring is held in place by the center tubes. The tubes are welded to the header tanks then welded shut.
The upper tank is formed out of two pieces of aluminum hammer formed over an MDF dye. The two halves are tacked together using the TIG welder then finished using a oxy/acetylene torch. This picture is taken after gas welding the two halves together.
This picture shows the end of the lower tank assembly. The lower tank is bent on a brake and has already been welded to the lower header. The end plug has been fitted and is about to be welded in to seal the tank. The space on top of the header will eventually be filled with thermal set epoxy to reinforce the joint and fill any pin holes.