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"Built Dam Strong!"

06 June 2012

Weld . . . wait. Weld . . . wait. Even while tacking.

If you recall, I left off last night with a hole in the joint between a primary merge with a filler rod and an electrode sticking out of it. Well, that was the first task of the day and after some grinding and welding with a fresh tungsten, I ended up with this:


After that, I started fitting the 90* bends:
The #4 is closes to the camera and also on the bottom of the merge. #3 is next to it. These are installed with the normal leg lengths of the bends. The two "top" primaries are shortened by the diameter of the plus a 1/4" in order to fit them. I do this because the #1 and #2 primaries are "reaching" from their respective cylinders. Does this lead to the all hollowed "equal length primaries" you hear so much about? No. I don't really care for equal length primaries, as I want to widen torque curves into plateaus, not have silly peaks that aren't much good for anything but dedicated one note racing. 

I use tape on the tube to make sure I cut and finish the tube straight:


 I love this technique, especially since my bandsaw doesn't cut particularly straight without constant attention. heh

More mockup and checking fit:



 It is WAY better to have to make a few cuts to trim something down than to cut too much. Slow and steady saves time in the end. 


I couldn't take a whole lot of pictures of in process methods with the rest of things because I needed 3 hands (had a helper hold things in place at times) to hold everything, measure and test fit. 

Mocking up the rest of the primary for #4:

Rolling stools with adjustable seats can be handy for mockup, too: 


Here is #4 tacked up and in place:


Note: The collector is NOT supported by ANYTHING other than runner #4. That is how strong tacks SHOULD be. 

Here is a side view of the collector (for you, Dan): 

If you enlarge the pic, you can see that the bottom of the collector is about on the same level as the backside of the oil pan (the lowest part). There is enough space between the pan and collector, but I wouldn't want to have it get any closer to allow room for some movement when the header is heated up and also for the header wrap that is going on the header to cut down on radiant heat. 

This is an example of too long better than being too short: 

After some trimming, making sure of the angle and squishing the tube in my vise to more closely fit the oval shape of the port, I had 2/4 of the runners tacked into place:


There is a huge gap between the last pic and this next pic, but it took a while. Actually, that is an understatement. LOL! It's SOOOO good to see this thing finally take shape!


Collector and primaries:


Front shot. The angle is a bit exaggerated due to the funky angle I held the camera. 


Here is the end of the collector:



I am actually NOT going to weld on the megaphone and exhaust extension onto the header, since the car this is going is nothing I am familiar with and has major components moved around. 

Tomorrow is going to be more welding. The reason why I titled this post what I did is because even with tack welds, maybe even ESPECIALLY with tack welds, you CANNOT rush things. As I was tacking the last runner (#1), I could hear all sorts of pops an pings. Go too fast, and nothing will go together correctly. 

I have to weld all the runners and make 8 tabs for the springs that will hold the sections together. I have concerns about one of the collector slip fit sleeves. It is a bit loose, but I know a few ways to make sure it seals, though after the header warms up, I anticipate the header will seal extremely well. 

Busy, crazy day tomorrow. Time to get some good rest. 
















2 comments:

  1. have you ever used hose clamps instead of the tape? works really well for making straight lines. used it a couple of times for making driveshafts

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  2. I have seen guys use them, but the tape works fine for me and I prefer it for several reasons:
    1. Tape is faster to apply.
    2. I don't have to weld around the tape (I can peal and tack easily).
    3. Most worm-gear clamps don't last very long in that application and I haven't found any wide enough to really drill the holes needed for tacking with them in place.
    4. Since they don't last long, they are much more expensive than tape.

    if I can find WIDE clamps that I can drill holes for tacking in without worrying about the longevity of the clamps, I would probably used those in a heart beat!

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