Abarth Swap making some parts.

TonyK

True Classic
Working on these cars some times brings about an obsession in my way of thinking. Building an exhaust system from Stainless Steel in my mind is the only way to go, but the X has cramped quarters and needs tight bends so I wanted to try and make a stainless steel 2" fabrication donut.

It was apparent that I would need a punch and die set, so I purchased 2 slugs of steel 6" in diameter and starting turning out the punch and die on my lathe.



It take a fair bit of time to turn out a part like this and I have great difficultly is seeing the negative part ( die ) in my mind and when I make it. Templates from card board help me through this issue of perspective.






Here I am taking some measurements to figure out where the limits are for the die. I am using 16 Ga Stainless and I require a clearance of.050" between the die and the punch.



This is a 1 7/8" donut and is what I am trying to make but 2". The cost is prohibitive with the Canadian dollar being so low and the cross boarder shipping and import charges.



Projects like this take a fair bit of time and learning how to shape metal becomes a trial and error effort. I still like the challenge, but labour to dollars, well it would be cheaper to purchase than go through all of the machining I did.


The first shot at forming fell short. It is trying to figure out the stretch of the metal and how it compresses as well. The hole in the middle of the blank is only 5/8" in diameter but needs to be stretched to 1 3/4" for the internal radius. So a set of punches were made and my 20 ton press is used to form the metal.





More on this latter.

TonyK.

Grimsby Ontario Canada
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Working on these cars some times brings about an obsession in my way of thinking. Building an exhaust system from Stainless Steel in my mind is the only way to go, but the X has cramped quarters and needs tight bends so I wanted to try and make a stainless steel 2" fabrication donut.

It was apparent that I would need a punch and die set, so I purchased 2 slugs of steel 6" in diameter and starting turning out the punch and die on my lathe.



It take a fair bit of time to turn out a part like this and I have great difficultly is seeing the negative part ( die ) in my mind and when I make it. Templates from card board help me through this issue of perspective.






Here I am taking some measurements to figure out where the limits are for the die. I am using 16 Ga Stainless and I require a clearance of.050" between the die and the punch.



This is a 1 7/8" donut and is what I am trying to make but 2". The cost is prohibitive with the Canadian dollar being so low and the cross boarder shipping and import charges.



Projects like this take a fair bit of time and learning how to shape metal becomes a trial and error effort. I still like the challenge, but labour to dollars, well it would be cheaper to purchase than go through all of the machining I did.


The first shot at forming fell short. It is trying to figure out the stretch of the metal and how it compresses as well. The hole in the middle of the blank is only 5/8" in diameter but needs to be stretched to 1 3/4" for the internal radius. So a set of punches were made and my 20 ton press is used to form the metal.





More on this latter.

TonyK.

Grimsby Ontario CanadaView attachment 16585 View attachment 16586 View attachment 16587 View attachment 16588 View attachment 16589 View attachment 16590 View attachment 16591 View attachment 16592 View attachment 16597

You're crazy. In a very very good way, but still loco in the head :D
 
Agreed. I thought I was crazy, then thought Rodger was crazy, or Hussein or stingray or... while the list goes on, you take top crazy prize: billet SS exhaust. Nice.

I say keep it up and keep posting :)
 
You're crazy. In a very very good way, but still loco in the head :D

Are you saying you only just noticed this?

This man has been showing more than signs of this illness for well over a decade. This is based only on what he has willingly revealed, imagine just how deep the problem really is. :D

Very cool indeed, can’t wait to see some of the results.
 
Continuing on.

Here are a few more pictures. I did shoot some video but need to compile it and upload it to my channel. Will get to it in the next week or so.

Blank is now ready to be put into the die.

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The interesting thing I find with Stainless Steel is that it is fairly ductile and does not have much come back when formed.



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When the blank is the correct size it follows the punch and folds under the die.

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It takes about 15 ton to close the punch and die but I work the press in quarters an inch from the edge to make sure it presses down as far as it can go.

If I had a stamping press the edge take up would most likely flow out. Instead I used a ball peen hammer to take out the high spots. It came out fairly well and will suit my needs for an exhaust system.

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Here I hammered out the high spots before welding.

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Welding is TIG .040" tungsten at 25 AMPs DC. No filler metal required.

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I think I can work with this. The one donut half was a bit crinkled, so I only used 1/2 of it plus I welded in a trial section.

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TonyK.

Grimsby Ontario Canada.
 
Any chance of machining a deeper vertical ridge on the outside face and the same on the inner post of the top cover half and then adding a ring to create a matching depth on the lower mating half. Then adjust the blank so that you have a clean edge that you can trim down to the point where you want to weld the two halves together.

This would get rid of your ragged edge where you want the faces to meet in a good butt to make welding easier and make a cleaner final part.
 
Another thought would be to pre-shrink the outside edge before putting it in the die. Did you freehand the radius's on the dies or have some kind of radius turning tool?
 
Another thought would be to pre-shrink the outside edge before putting it in the die. Did you freehand the radius's on the dies or have some kind of radius turning tool?

I wondered the same thing. I am thinking he just loosened the bolts on the compound and swung it around, but I am definitely curious.
 
A friend of mine wanted to make aluminium donuts for turbocharger inlet piping... instead of going the die and punch method shown here he took a more novel approach that worked surprisingly well.

He simply cut two discs out of flat sheet with the required OD and ID for the donut he needed, he then TIG welded the flat discs together, and into the flat of one disc welded a hydraulic JIC fitting. He then connected the fitting to his hydraulic porta power pump, and proceeded to pump hydraulic fluid into the void between the two discs, I was pretty amazed at his ingenuity and the almost perfect alloy donuts he created.

SteveC
 
Any chance of machining a deeper vertical ridge on the outside face and the same on the inner post of the top cover half and then adding a ring to create a matching depth on the lower mating half. Then adjust the blank so that you have a clean edge that you can trim down to the point where you want to weld the two halves together.

This would get rid of your ragged edge where you want the faces to meet in a good butt to make welding easier and make a cleaner final part.

Although this sounds workable, the issue here is that the larger that the outside diameter of the blank is the more shrinking of that outside edge will be required thus adding to the problem. In the process of forming there are parts that are stretched on the blank and others that are shrunk. Stamping at times is done in stages with sequenced dies and punches to do the forming. The possibility to preform the outer edge prior to squeezing 100% should yield less crinkle, but the metal has to be taken up somewhere or the blank must be thinner at the outer edge.

TonyK.

Grimsby Ontario Canada.
 
A friend of mine wanted to make aluminium donuts for turbocharger inlet piping... instead of going the die and punch method shown here he took a more novel approach that worked surprisingly well.

He simply cut two discs out of flat sheet with the required OD and ID for the donut he needed, he then TIG welded the flat discs together, and into the flat of one disc welded a hydraulic JIC fitting. He then connected the fitting to his hydraulic porta power pump, and proceeded to pump hydraulic fluid into the void between the two discs, I was pretty amazed at his ingenuity and the almost perfect alloy donuts he created.

SteveC

A bit off topic, but that reminds me of this:
 
I wondered the same thing. I am thinking he just loosened the bolts on the compound and swung it around, but I am definitely curious.

I took an simpler method of machining the radius, although a radius attachment would be the solution. see pictures. Chatter due to the amount of engagement in the work can be a problem.

TonyK.

Grimsby Ontario Canada

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Where in the exhaust do you need a 180 or greater arc? Is this for header construction? Any drawings or pics of intended end result? I can’t visualize it.

My old header lifted the turbo up oretty high, so had that 180 arc. I wouldn’t contemplate welding such a thing. I’m not really looking forward to welding my NA header/collector, and that will be a breeze compared to a compact turbo header

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Where in the exhaust do you need a 180 or greater arc? Is this for header construction? Any drawings or pics of intended end result? I can’t visualize it.

My old header lifted the turbo up oretty high, so had that 180 arc. I wouldn’t contemplate welding such a thing. I’m not really looking forward to welding my NA header/collector, and that will be a breeze compared to a compact turbo header

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Here are some pictures to explain what was built. Tight radius at times is a must.

TonyK.

Grimsby Ontario Canada.

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Interesting. I'm assuming the pipe length is a neccessity to maintain decent exhaust note, and/or back pressure? Most small turbos aren't happy with a wide open exhaust.

EDIT: Just noticed how long the right axle has been extended. That hasn't created any balance/harmonics issues, or reduced CV life? Looks long enough a span that an intermediate shaft with a carrier bearing would have been an option.
 
Hussein I will share a bit on the axle. So first off, since the Abarth is front wheel drive the right side of the stock car has a pillow block and has the CV's and shafts are the same length on each side. Now in the X the engine is put into the rear of the car so the pillow block is not needed because torque steer is not a problem in a rear wheel drive car. Just to let you know the half shaft is shortened, not lengthened, this is a modified stock X1/9 right half shaft.. This is due to the fact that the differential case is wider than the X differential case. One other tid bit. The X shafts are the same configuration ( splines as on the Abarth). As for the exhaust, yes the length is there to provide some back pressure although the stock Abarth pipe is about double this length. Bob Martin wants his exhaust to break into a left and right side without the length. We will see how that works out.

TonyK.

Grimsby Ontario Canada.
 
I'm impressed Tony, a question on your radius tool, is it a fixed tool that you set to where you need to trim then run it in with the cross slide or a combination of cross slide and compound slide. And just nibble away the high spots to match your CAD template? CAD = Cardboard Aided Design....

Even with a radius turning jig it would be hard to get the center section, the other side would be in the way for part of it. This is what I did to cut a radius it replaces the compound slide. It would work for most of the male die except the very center and if you move the tool holder to the left it will do concave cuts but I think there would be to much interference to work on your die. I really have a desire to try this, but with the price of already made ones in the states I doubt I will, and I have way to many projects anyway.
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