Before I can actually start the '40 and hear it run, I want it to have an exhaust. The main reason for this is because I want to be able to hear the engine in case something bad decides to happen. Now, I did not do a rebuild, nor did I even go to the extent to give it the Sherwin Williams overhaul. I simply pressure washed it and stuck it in. I mean after all, the stand up individual that I received the engine from said it ran, so, I guess that is good enough for me. Besides, 235 Chevy 6 cylinders are quite readily available on the cheap.
When I build headers, I usually start with a pile of combo bends from Speedway Motors. These bends have the most consistent tubing shape though the bend that I have been able to find. They are not overly priced either. I like using 18ga on hot rods and such where weight is not overly important because the added thickness allows for grinding and finishing of the welds without making the walls too thin. I should have taken some shots as I was tack welding the pieces together but I was lazy and did not. This is what you get...
The welds still need to be ground and finished. Typically, if you tig weld, a right angle grinder with a 2 1/2" roloc disc is sufficient enough the finish with. If you use a mig, I would recommend to start with a 4 1/2" angle grinder to remove most of the weld material then proceed with the right angle grinder. I'll follow up with a used worn out roloc disc to remove some of the deep scratches and then polish with 180 grit emery cloth and eventually end with a 220 grit orbital sander. The polishing step is by far the worst part of the entire process, but it is the most critical. If you want to get the headers ceramic coated or even chromed, all of the scratches have to be removed. You might be thinking that the ceramic coat will "fill in" some of the scratches. It does not completely. It is, though, much more forgiving that chrome. Think about it, why is chrome so expensive? It is not the cost of the actual chrome, but the prep work of polishing the the raw metal to remove all of the imperfections and scratches. Here are some headers I have build...
Also, I figured I would throw in a shot of the gas tank recently covered here all installed and plumbed.
