Proposed Design - The Short Lady Revealed

Moderator: Mike Everman

Re: Proposed Design - The Short Lady Revealed

Postby Mark » Tue Sep 21, 2004 1:05 pm

Yes Larry, it probably should be seen as a multi port breather, but it would make for a good illusion if you burried it up to its neck in the ground and fired it up. People could come from far and wide to see the magical "Shroud of Lorin" or some other creatively named device such as the Geyser-o'-dyne.
I'll have to read up and see if I can find what the heck it was used for.
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Re: Proposed Design - The Short Lady Revealed

Postby steve » Wed Sep 22, 2004 1:29 am

No time to write much now but here is a pic:
Attachments
DSC01629.JPG
focused wave construction nearly complete
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Two Pitfalls

Postby larry cottrill » Wed Sep 22, 2004 12:10 pm

Steve -

In welding in the intake, I know of two potential difficulties:

First, the rearmost point of the weld around the hole will probably be difficult, because there's so little room to work in between the 'inside of the elbow' and the cone. I learned this in the Fo Mi Chin engine, and it will be even worse here, because the space is even tighter. You must not allow a leak at this point! What I did to make it easier on the Elektra II was to carefully pre-weld a little dab of metal right at the rear of the slot, and file it back so the intake would fit tight up against it - the close contact makes it relatively easy to weld it to the intake tube without having to get filler rod in there to do it. In the picture below, you might be able to just see the little 'pre-tack' weld in place with the file above it at the angle I wanted to hit. I used a small half-round file to carve the inside edge.

Second, it will be difficult to tell when you have the bent part of the intake pipe going straight in. In both the Fo Mi Chin and Elektra II, the intake could be pre-welded to the exhaust pipe, so it was easy to get good alignment. With the Focused Wave, the only thing you can do is use a pen light and sight down the exhaust pipe to see how it lines up. The other thing that makes it difficult is that so little of the bend remains on the outside, making accurate alignment hard to judge. Anyway, you should allow enough side-to-side 'slop' in the oval hole to allow for a little adjustment after that first tack weld. Of course, it doesn't have to line up perfectly dead-center, but it ought to be as close as you can get it. Again, I think starting out with the little pre-built tack weld at the rear will give you the needed flexibility to adjust it before you go around sealing it up. If I'd thought of this before now, I'd have recommended welding in the intake before welding on the front dome ... oh, well.

If you do tack it at the rear first, take into account that the welding you do in front will pull the rear of the intake pipe up out of parallel with the tailpipe. What I would do is tack it at the rear with the edge of the flare touching the cone, work out the side-to side alignment, then make a solid tack weld right at the front. This should pull the rear of the intake away from the cone a little as it cools, approximately into parallel with the big pipe. Then, weld a little at the rear, a little at the front other side, a little at the rear other side, a little at the front first side, and so on until you complete the seam. That should keep things balanced up pretty well in terms of shrinkage. Again, don't get hung up on 'perfect' alignment; a degree right or left, or up or down, is inconsequential.

Again, what you've got looks wonderful.

L Cottrill
Attachments
ElII_tailpipe_notched_crop1.jpg
Notch for intake in Elektra II tailpipe front edge - note the tiny weld, being filed for close contact with the slanted part of the intake pipe. Photo Copyright 2004 Larry Cottrill
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