Tag Line

"Built Dam Strong!"

04 January 2012

Justin's header, and how much I love pie!

I made a LOT more progress on Justin's header today.

I grabbed a bit better pic of the insides of the collector. The insides of the collector might not look too terrible from the pic, but the un-cleaned up welds are just unacceptable in a header that is supposed to be custom and CLAIMED to have a Burns collector. 

Here is the header on my spare engine I use for mockup:

The original plan was to use the cone and pie cut just the cone to wrap under the oil pan, like so:

Here's the original collector tube sort of as it sat originally, before it cracked off. 

Looking at how everything was sitting, I remembered that I had some pieces leftover from another project I am working on, so I dug them out. Right away, they fit together OK. Not great, but, with some work, they would be useful. The reason why I decided to use these pieces was that they are larger than the long cone, which would allow me to start the pie cuts up farther, keeping the radius as large as possible. 

Using two pieces of wood to clamp the pieces, I started making pie cuts! 

First cuts, though I didn't get the angles quite right as you'll see in the second pic below. 

After a bunch of careful cutting and filing, things started to look much better:

The shapes don't match up exactly as the cones the pieces were cut from, and all the cones, are not exactly perfectly conical. They are close, but not exact. The company I buy all my bends and cones from does a FANTASTIC job, though, and it's just the nature of the material and process used to make the cones and is unavoidable, at least at this price point. The fix for this when I am welding stuff together, I will tack the points of the cones that match best, and gently manipulate the reaming overlaps out with careful forming. it takes time, but, it is something I am good at. 

Then, I went onto the new cone. Laying out things exactly isn't too hard with some creativity and painter's tape. I marked down 1/4" from the wide end of the cone, and carefully taped from that point to the tip of the cone exactly opposite of the seam. The seam is just an easy way to keep things lined up, and it keeps the shape mostly consistent as you make your pie cuts.  

I have a portable band saw (cheap Chinese model, but it works darn well with some Starrett blades) that I use to make all these cuts. It took me a few cuts to get into a groove, so I had to clean up edges with a file, which takes time and effort. 

One of these years, I'd like to get a big stand mounted belt sander, as I plan on doing a bunch of header fabrication in the future, including turbo manifolds, but that is another story.

Here's the first to pieces mated up to the new cone:

And more pie cuts: 

I had to stop here for that day as I had to head to the post office to mail off a chipped ECU (I tune, too) and a new chip for a previous client who will be turbocharging his engine in the near future. Tomorrow, I will be finishing up the pie cuts on the new cone. After that, I will be shifting to another project that I have to prep before I get to welding all this stuff up.

After I get the cone made into delicious pie slices for this header, I have to form the cone to fit the collector, install provisions for a header support (especially important with how delicate the actual header is), and then weld everything up. That isn't a long list, but it will take time to do all of that stuff. 

Fun stuff!