Headers are done. Time for a burrito

Not counting the endless days of forming the pipes with plastic modelling blocks, it’s taken me nearly 9 months to duplicate the plastic model in metal. In reality it was only the primaries that had to be made up using the blocks, after the four primaries were paired into two, the rest of the routing was exposed enough where I could continue to extend the header using the actual metal tubing instead of plastic blocks.

This past week was spent bringing the secondary pipes together into the final Y collector and today I was able to complete the headers by welding the Flow Master ball type couplers to the ends of the collectors.

No matter how much I sanded and cleaned the mating surfaces and surrounding areas with acetone, I still wound up with spots that were somehow contaminated. Last night I was thinking that something was obstructing the flow path of the shielding gas so when I got to the shop today, I swapped out the torch. I didn’t like the way the electrode didn’t quite center up in the nozzle of the old one. I managed to get a more consistent bead but I still had a few spots that sucked. Some areas I could grind out the afflicted weld and then reweld it with the tig. Some worked and others didn’t. In the end, I cleaned out the bad weld once again and then hit the spot with the Mig welder just like I did with the flanges. I quit caring if it was the proper way to weld the headers, I am just tired of working on these pipes.

I’ve read differing opinions on back purging. Everyone agrees it’s a must when welding up stainless steel pipe but only a very few think it should be done on other types of metal. I’m of the mind that if I build another set of pipes, mild steel or stainless, I’m going to back purge. I’m pondering this because I noticed that the majority of the spots that were contaminated were the areas where there were gaps. It didn’t matter if the pipes were being butted together of slid into one another to cause the metal to overlap, any gap had issues. Sure, I tried to grind, cut and pound the pieces for as tight a fit as possible but I still ended up with gaps. I think if I were back purging, these gaps wouldn’t have presented a suck hole and I would have had shielding gas coming from both sides of that opening. I believe the gaps allowed air to mix with the argon which allowed the contaminants to get in. It’s all a theory of mine. I can’t say for sure until I try it.

Nine months is a long time to build a set of headers. If I had been working on the pipes every day, 8 hours a day, nine months is ridiculous. It wasn’t like that. What I’m doing is my hobby. I work for a living so I could only work on the pipes sporadically. If you broke down the nine months into actual work time, I’d say it was still like a good four months of work. Still a long time. A lot of that time was spent just trying to figure out what I was doing.

I tried Tig welding back in 2019 when I had to widen the replacement floor pan, there’s a post about that somewhere in this blog, but I failed miserably. I couldn’t find the consistency so I gave up and went back to the trusty Mig welder. When I started up on the header again 9 months ago, I was determined to learn how to use the Tig welder. I went through a tank of Argon trying to figure out why my first pass would be a decent weld and then the second and third were out of control; contaminated beads, blowing holes and then no penetration. When I started on my second tank of Argon, I was getting tired of the little shocks I kept getting from the hose and torch. By accident, I was holding the torch in my bare hand and I stepped on the pedal and felt air coming out from under the torch handle. I pulled the handle down and found that the hose had a split in it. I ordered a new hose and torch and when I went to replace the hose I found another reason for low gas flow, the other end of the hose that screws into the welder was barely holding on by a few threads. The hose in reality screws into a brass fitting that’s a half twist turn lock into the welder. The hose assembly was already assembled when I took delivery of the welder. Once everything was replaced and tightened up properly, I sat down to try my hand at Tig welding again, GTAW welding for you purists, and suddenly I discovered I could actually make beads with the welder. I definitely learned a lesson of what happens if you don’t have shielding gas. Its’ called kaka. Oh! No more shocks from the hose. Imagine that.

With the headers finished, I can now think about other areas I need to take care of and the great part is that none of these other projects won’t even come close to the time suck that these headers have been.

So what’s still on the whiteboard? The obvious thing is the exhaust from the header to the back of the car. I bought a Magna Flow exhaust system for a 69 Mustang so there’s no fabricating needed there, just a bit of fitting. A little welding to integrate the other half of the ball type coupler to the Magna Flow exhaust. Oh wait, I have to figure out how get the pipes from the mufflers, over the rear end and out the back. I have a totally aftermarket rear suspension and there isn’t a whole lotta room to get the pipes through there. Ah hell, if the exhaust dumps out under the car right out of the mufflers, then that’s what will have to happen, we’ll see.

After the exhaust I still have all new brake lines, gas lines from the tank to the engine and a return line, I’m running EFI on the engine, I still have the wiring to do and build the engine. Part of the engine work is done. I had the machine shop build the short block. Even with that done, there’s still a lot of work to be done when you’re building an engine that has a camshaft over each head and a six-foot chain tying everything together.

I still have to mount the radiator. I bought an aftermarket one which will require some cutting on the radiator support to make it fit. I’m a huge fan of a car that doesn’t overheat.

Let’s see, what else? Ummm, I still need a drive shaft. That reminds me, Once I finished the headers and cleaned them up a little, I first mounted the mini starter and then bolted the right side header up to check for clearance to the starter. I have a minimum of an inch from the exhaust pipe to the starter solenoid. The starter manufacturer recommends 3/4 inch so I’m golden. Even though the starter has room, there isn’t enough clearance to remove and install the starter with the header on. I have an idea how to make that work. I’ll post a story on that if it works.

I bolted the headers onto the engine and then went to the car and bolted in the steering gear box and hooked up the steering linkage. I couldn’t fit the header up under the engine with the steering gear in place. The fit is so tight I had to remove it when I was test fitting the header as I was building it. I’m pretty sure that I have the headers hugging the block so tight that I can bolt the headers to the engine and then lower the engine, trans and headers into the car as one unit.

Once I had the steering bolted back together, I wheeled the engine over to the car and engine hoist and shortly after that, the engine was being lowered into the Mustang. The live wheels on my hoist don’t want to behave so it took some kicking and cursing to get the hoist into place. Got the engine in and onto its mounts in one try. The headers cleared everything they’re supposed to. Put a jack under the transmission and called it a night.

Yeah, still a lot of work to do but I think I’m finally seeing light at the end of the tunnel. I just hope it’s not a train coming from the opposite direction.