MOTOR...Exhaust cones...tech

[Jethro]

Here's my contribution to "tech week". A few guys have asked me where I bought the cones for my 6 cyl exhaust that I made. I didn't buy them I made them from 18 ga cold rolled sheet metal. I found a formula to draw out a pattern for cones, and it's really not that complicated.

Start with a center line longer than the cone that you want to make

draw the cone in 2 dimensions that you want...ie 4inch on the big end , 2inch on the small end ,and 20 inches long.make sure it's centered on the line you drew first.

extend the sides from the small end until they meet, this will be your axis for your arcs.

Use a compass or a string and a pencil and draw arcs at the small end and the big end that extend well past the original drawing.

now do the math...to get the length for the ends multiply pi times the desired diameter...3.14x4=12.56 for the big end and 3.14x2=6.28...then divide the measurement and lay out marks on the arc on either side of the first center line.

connect those marks then you will have a pattern for your cone

[Jethro]

pics of the cones I made

[flt-blk]

Those are nice, I didn't think I could keep them from going oval when rolling them so I just bought a couple.

I found them in the speedway catalog for $19.95.
1 5/8 Cones to 3 1/2 32" long.

As soon as I get some pic's I can add to this thread with my custom collector caps and mounting system.
TZ

[Tim]

great tech,

[manyolcars]

thets rill purty jethro. now tell us how to roll the flat pieces into cones

[Tuck]

what did you use to roll them? what guage steel did you use?

[Unkl Ian]

The patterns I can do,by a couple methods.
Rolling them,with or without the proper equipment,is where I run into trouble.

[Tuck]

whats the proper equipment http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif I wana do this...

[flt-blk]

I was going to try a piece of all-thread with several progressively larger size discs spaced over the span. But I couldn't figure out how to curl the ends enough to keep it from going oval/flat.
TZ

[Unkl Ian]

[ QUOTE ]
I was going to try a piece of all-thread with several progressively larger size discs spaced over the span.

[/ QUOTE ]
That is another way to make patterns for straight cones.
Correct size discs top and bottom,spaced the correct dimension appart.
Add a start/stop mark inline on each end.
Roll across a large piece of paper one revolution,the start/stop points give the ends of the straight lines,the tracks of the discs show the correct arcs to be cut.

[DrJ]

A sheet metal roller usually can be set so the rollers are not parallel to each other. This will roll a cone shape.

The Morgan factory in England, hand rolls their aluminum hood sides over an old tapered tree trunk.

[FeO2]

Jethro,Very nice work there.What I realy like is that intake manifold.I was thinking all day about how to get a nice even fuel distribution with an odd carb to port ratio. Hope you don't mind if I steal your design.Very impressive job there. Charlie

[Jethro]

Sorry for not mentioning how I got the steel from flat to round http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gifI used 18 ga cold rolled and I had a friend who has a sheet metal shop run them through his slip roller like DrJ said . He had the tension set different on the rollers so it would taper. The metal only took a partial round shape and I had to hand form the rest of the curve. I used a piece of 1-1/2 inch bar clamped in a vise and I formed the curve around that.When I was happy with the shape I tacked it at both ends with a mig , then put a few tacks along the seam then finish welded the rest then hit it with the grinder.

[Bruce Dorsi]

Please excuse me for jumping onto this thread before posting a proper intro, but I thought I could add some useful info before this thread falls into oblivion.~~~~~~~~~I saw a set of homemade "Limefire" headers and was impressed by the workmanship. When I asked the builder how he made them, he said he "cheated!" Instead of trying to make flat metal conical in shape, he started with exhaust tubing with a diameter equal to the large end of the cone. .....He slit the tube lengthwise, and used several worm-drive hose clamps along its length. .....By tightening the hose clamps different amounts, he was able to create a cone to the taper he desired.Once the desired taper was achieved, he marked the tube along the overlap, then removed the clamps and cut along the marked line to remove the excess metal. .....Using the clamps again, he brought the trimmed edges in alignment and welded them up. They turned out beautifully!Allow a little extra tubing length for trimming the ends square. ......The tubing used can also be larger in diameter than the large end of the cone. ....It will just require more trimming.Using this method can allow longer cones to be created, since the length is not limited by the capacity of a roller.

[Bruce Dorsi]

OK, who will PLEASE explain how to create a new paragraph while typing my text? ..... I double-spaced as usual, but my post appeared as a run-on paragraph.~~~~~~~~~~Any help will be appreciated! ...Thanks!

[DrJ]

[ QUOTE ]
OK, who will PLEASE explain how to create a new paragraph while typing my text? ..... I double-spaced as usual, but my post appeared as a run-on paragraph.~~~~~~~~~~Any help will be appreciated! ...Thanks!

[/ QUOTE ]

A while back C9 mentioned that the post is easier to read if each sentence is RETURNed to the next line and paragraphs are double RETURNed like this;

"Please excuse me for jumping onto this thread before posting a proper intro, but I thought I could add some useful info before this thread falls into oblivion.~~~~~~~~~
I saw a set of homemade "Limefire" headers and was impressed by the workmanship.
When I asked the builder how he made them, he said he "cheated!"
Instead of trying to make flat metal conical in shape, he started with exhaust tubing with a diameter equal to the large end of the cone. .....
He slit the tube lengthwise, and used several worm-drive hose clamps along its length. .....
By tightening the hose clamps different amounts, he was able to create a cone to the taper he desired.
Once the desired taper was achieved, he marked the tube along the overlap, then removed the clamps and cut along the marked line to remove the excess metal. .....
Using the clamps again, he brought the trimmed edges in alignment and welded them up.
They turned out beautifully!

Allow a little extra tubing length for trimming the ends square. ......
The tubing used can also be larger in diameter than the large end of the cone. ....
It will just require more trimming.
Using this method can allow longer cones to be created, since the length is not limited by the capacity of a roller."

I use it some of the time for punctuation and sometimes just for emphasis.

I used the line RETURN, (ENTER, on a PC? I have a Mac and the keyboard is a bit different.) not the space bar.

[Bruce Dorsi]

Thanks, DrJ. I did use my RETURN key as you suggest, but the text did not appear on the board the same as it did in the "Preview" box.I'm trying that again right now.I'm just learning my way around the HAMB from this side of the door. ...It's much easier to be a lurker!

[Bruce Dorsi]

Well, that didn't work for me, again!.......My apologies to all for mucking up this fine thread........I'll try to find somewhere else to practice!

[roadstar]

Bruce just hit the ENTER key twice

And you will have beautiful spacing.

See http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

Oh And I did the method you described when I made my first set of out side headers back in the early eighties.

I got a piece of 4" exhaust tubing and cut a pie shape out of it and using a plumbers style vice brought the two halfs togeather and preso I had a cone.

[flt-blk]

Here are a couple shots of the headers I am putting together.
I thought about buying a Speedway kit but couldn’t swallow the
$175 price tag. I am not quite $80 into this and have almost all
the pieces.

These are going on a Studebaker 289 in a Model A pickup with fenders.

At this time all I have finished is the caps for the cones.
Pic #1 is the completed cap installed with wing nut and cotter pin to
keep it from rattling off.
The cap has a grove cut into it that seats over the lip of the cone. I am thinking the rope type seal from a wood burning stove can lay in ther for a gasket.

[flt-blk]

This is inside, the pin is a carriage bolt with a hole drilled for the cotter
pin. If I ever need to change the pin it unbolts very easy.

[flt-blk]

Here is the inside. I squared a hole in a washer to fit the carriage bolt.
Marked and drilled 3 holes in the cone and poked some 3/8 rod through.
After welding to the washer and the pipe, a little clean up and you won’t
even know the bars are there.

[flt-blk]

Last but not least is my header kit by TZ. Home made 3/8
flanges for the Studebaker motor. A couple 1 5/8 mandrel
bends, the cones and new bolts, all from Speedway for less
than $80. The dump to the existing exhaust and mufflers I can make from
leftovers.
TZ

[Plowboy]

What are those nifty thumb screws from? Or, where did you find them?

[flt-blk]

King-O-Lawn Power Edger

is what is cast into the wings. They were holding the two piece mower handle together.

Thanks to 67ImpWagon and Honest for donating them.
TZ

[flt-blk]

I also heard big wing nuts were used to hold the spare tire
in some 70's cars, If you can't find a King-O-Lawn of your
own.
TZ

[Kinky6]

Hey, Jethro, thanks for the post.

And for the rest of us amatuers, a good excuse to quit whining and go buy a welder http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif

Later, Kinky6.