Header Flanges - Sources?

[Mattax]

We've had a delay on starting my headers 'cause my builder's usual source (a) sent the wrong flanges (b) are out of stock on the correct ones.
My builder would prefer 3/8" thickness in stainless but is willing to try plain steel.
We'ld like to the first step to 1.5" tubing IF Brian can blacksmith the 304 to the flange. He's cautious about how much he can successfully work the 304.
Project topic here: viewtopic.php?f=1&t=42702&p=541776
So, who carries flanges for stock Chrysler LA - 340 ? and are some better matched to the top of the ports than others?

Here's a couple I've tracked down from posts here -
Headers by Ed website shows he has (in plain steel) flanges sized for 1.5" tubing, and is willing for extra cost to make them in 3/8".
http://headersbyed.com/__chrysler.htm#3 ... 20Chrysler
http://headersbyed.com/_headerflange.ht ... planations
SPD shows only a 1.625" as the smallest port, either plain or 304. http://www.spdexhaust.com/MoparB.html#

[groberts101]

here you go in steel.

http://www.stans-headers.com/chrysler_flanges.htm

Been using these guys more lately too.. mainly because they're near me for local pickup. Excellent workmanship, thicker stainless material, and pricing is pretty damned good for what you get in the final product. Not sure what their exit sizing is on the LA stuff but I do know they can shrink an existing digital pattern to whatever you want with smaller increases in pricing than a full off custom pattern.

http://www.stainlessheaders.com/engineheaderflanges

Plenty of well known shops will make you whatever you want too.

When fitting the pipe to flange.. how does the center ports end up for overall perimeter size compared to the end ports sizing?

[jmarkaudio]

http://www.spdexhaust.com

[Mattax]

Thanks for the replies.

When fitting the pipe to flange.. how does the center ports end up for overall perimeter size compared to the end ports sizing?

If I am understanding your question, I can only answer based on my tracing from a similar (360) set of heads.
Following the outline of the center ports with a scale, their perimeters are 4.5 and 4.56".
Doing the same for the outer ports comes up with perimeters of 4.87" and 4.81".
A 1.5 od. tube has a circumfrance of 4.71"

In terms of area, using the counting squares method, I come up with port areas of 1.5, 1.53, 1.59, and 1.47 sq in. (nos. 2, 4,6,8 respectively)
A 1.5" o.d. tubing (assuming .050" wall) is internal cross sectional area of 1.54 in sq.

I can post the tracing - or rather the transfer to graph paper - if that's of interest.

[Mattax]

So far, only progress on our end. I traced out the exhaust ports of the '73 340 heads (in the car) and found they were measurably taller and wider than the ones on the '78 smog castings: Approx 1.7" x 1.2" (outers) 1.68 x 1.3 (centers).

http://www.stans-headers.com/chrysler_flanges.htm
Two phone call later, couldn't get actual port dimensions. But its seems they don't make a flange for the 1.5" starter tube anymore. Rather they sell the same one as for 1 5/8 tube under the 1 1/2" part number. OK whatever.

http://www.stainlessheaders.com/engineheaderflanges
Seems to be issues with the flanges for an mopar LA causing a delay. Hence my search for alternatives/ backup.

http://www.spdexhaust.com/
Chris has tried to be helpful and asked for tracing (which I sent). As noted above, smallest flange opening is for a 1 5/8 tube. Based on '73 340 heads, this (using 1 5/8 or smithing 1 1/2) may be the only realistic way with an off the shelf flange.

Headers by Ed
Offers both a 318 and different (larger) 340 port flange for 1.5" tubing. But there will be a delay for and extra charge for anything over 1/4" thick. I'm hesitant to call - if you ask questions it can result in much more discussion than needed. At least that's what would happen 20 years ago.

[ProPower engines]

Why not find a company that does water jet cutting and make the pattern your self and have them cut.
If you are using std. 3/8" thick stainless Flat bar material then it should be no problem.

The issue that comes up it how much different the pattern needs to be from the finished size for the tracer to follow.
we used to be something like 3'16 smaller on the sizing for a local shop with a plasma cutting machine to make specialty brackets and other components for me some years back. If they will tell you what the pattern size difference needs to be that will save the setup charges for who ever is cutting the material.
the other option is to machine the stub tubes to fit common flanges if you can get them thick enough to surface grind after welding them up.
Dyna-tech is the only ones that I have seen do basic common headers with ground flanges. Most have a weld bead around the port exit to seal the gasket but they are never good enough for a dodge LA engine without leaks

[ijames]

At my last job we used www.bigbluesaw.com for waterjet cutting some plastic baffles for one of our products. We had a full cnc machine shop and sheet metal shop with a cnc laser and cnc plasma cutter, but no waterjet . They were great to deal with and the pricing, delivery time, and quality were as good as other waterjet shops I used in the past. They even bought a special material for our parts that they didn't already have on their list (1/16" PVC sheet). I bought 1500 pieces over about three years, so onesies to many is no problem. You can upload cad files (dxf, gif, png) or use their online drawing program, and then get an instant quote that even includes their volume discounts. Scan your port tracing and draw in the outside shape and bolt holes, adjust the port holes as needed to allow for the tubing wall thickness, then upload the file. You might be able to scan a gasket to get the outside shape. They supply and cut 304 SS in 0.375, 0.5, and 0.75 thicknesses (plus thinner, of course), so they can handle your flange. Anyway, just a good resource to have.

[Mattax]

Thanks (both Pro and ijames) for the info on custom. The answer is timing - we thought that someone would have mopar small block flanges on the shelf, and there was a fair chance they would be what we need. If I had known custom could have been faster from bluesaw, I'd probably have them by now.

A couple of technical issues with Bigbluesaw will be in scanning the tracing. First is that the scanners tend to introduce distortions. In fact all copiers do (but not blueline type machines). So there will be a little experimenting with the scanner. One way to minimize that would be to do the ports as individual pieces as we planned to cut them anyway. Once scanned, then they have to be converted from raster to vector - at least thats the case with my current scanner and software. Then all I have to due is learn the software well enough to enlarge the port size to accomodate 16 ga tube.

[ijames]

Many cad programs have a "trace" function, where you import a scan into one drawing layer and then switch to another layer and make it partially transparent so you can see the scan underneath, and then you draw over it. For a header flange I think the shapes should be pretty simple - a rectangle with filleted corners for the ports, round holes for the bolts, and then the outside outline. Could be one full length flange or could do one piece per port, or I guess two ports if you have siamesed ports in the middle. Point is, the shapes are very simple and therefore easy to draw from scratch in a cad program even without the scan to trace. If the port outline is more complicated, a D or trapezoid or oval or whatever, those are actually still pretty simple shapes to draw in a cad program so you just have to take careful measurements off of the tracing and then adjust for the wall thickness before you draw.

[Mattax]

Here's what happened.
SPD took a week to get back to me after sending a tracing. Chris said their flange would work with 1 5/8 tubing.
The day he called back, Stainless had shipped and I had picked up a pair of steel TTI flanges from my friends speed shop.
The TTI's have large ports and need to be milled flat. Doable, but the mounting holes are huge .380 where .320 would do. A lot of extra work to make them useable. However for the price, its to be expected.
The flanges from Stainless came in the next day. Port size much closer to the ports in the heads. Oddly the mounting holes are slots. It looks like we can work with these and that will save us the time and trouble of getting a pair cut to a dxf file.
I'll see if I can post some pictures.

[andyf]

Schoenfeld Headers has a large selection of Mopar flanges. They also have a variety of Mopar headers that other places don't have.

[Mattax]

See the post viewtopic.php?f=1&t=42702&p=573896#p573896 what we ended up doing.
We had a few extra sets made either for ourselves or others who are interested.

[Rick Finsta]

emachineshop.com is also a nice place to draw stuff up and have it custom made for you.