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the new icengineworksTM tack-welding clamps

Making exhaust headers has never been easy. Coming up with the most feasible layout that will fit in the available space is already hard enough. But it gets more complicated because then those complex runners, usually formed by welding short bent sections, need to be fabricated in metal with maximum precision.
Traditionally, multi-section assemblies (typically in exhaust header systems) are joined section by section: any two sections are tacked together and then the third is brought in and so on. The challenge with this technique is that even with the most 'precise' witness lines, it is difficult, if not impossible to preview the entire assembly at once to be absolutely sure that those initial tacked joints were correctly clocked. Even with extra pair of hands available, securing the tubes concentrically is very difficult. Therefore it is fairly common to have to break tack welds often to readjust. And since the same process is used (tacking joints one at a time), the potential source of inaccuracies continues.
What is necessary is a method or system that can firmly and accurately hold the tubes to be joined, regardless of their shape, in a way that is not too intrusive or uses a lot of space. A system that creates tight joints (gapless), that also guarantees that those tube ends meet in a concentric fashion and that can be used as many tubes as desired in any given assembly. And all this, in a package that can be operated by hand and that offers plenty of visibility to manually clock and adjust the tubes prior to tacking them together.
The new and upcoming icengineworksTM tack-weld clamps have been designed to solve these problems and to simplify the assembly and fabrication process of not only exhaust headers but any other tubular projects. By allowing the fabricator to preview, adjust and clock at will any, all the metal sections that form any multi-section tubular assembly, time-consuming adjustments are avoided but more importantly, a new level of assembly precision is achieved.
   

 

  
 The result is not only a much faster way to reach the desired shape the first time, but also the firmly supported joints feature no gap and are concentric for a smooth transition between bend planes. They are also easier to weld as there are no voids to fill, or overlaps to burn. The number of metal sections that can be joined are only limited to the amount of clamps available for use. Also, their modular construction allow the user to mix and match different sizes to support and preview stepped tubular section, that are fully concentric. Ample clearance between the rings allow the comfortable placing of tack-welds without any rush or fear of losing the fitment.
         
Traditionally, the tack-welding process during fabrication of multi-section tubular assemblies has been challenging because any joint to be created between any two metal sections can be a potential source of  inaccuracies as the assembly evolves. These can complicate the fitment of the runner, and in many cases, the fabricator needs to redo (by breaking and tacking again) some of these tack welds to make the assembly work. All this is eliminated with the new icengineworksTM tack-weld clamps which can be tightened with one hand and which are fully reusable and ultra compact, allowing the operator in the majority of cases to actually test the fitment in the vehicle.
The patented icengineworksTM tack-weld clamps feature two adjustable rings held together across the circle they form by two links, one fixed and one adjustable. The fixed link provides the pivoting point that allows the butt-to-butt joint of bent sections regardless of the plane of orientation. The second link, with an infinitely adjustable slot, provides the angular travel, or arc required to lock into position the shape and relative rotation between the bent sections. Of course, straight-to-bent, or straight-to-straight tube joints are even easier to achieve.
         
       

The process starts by having the parts that will form the tubular assembly cut and ready for welding. Designing with the icengineworksTM modeling blocks facilitates the fabrication since the resulting metal sections from the model feature tube ends that are perpendicular to the tangent line. This feature permits welding tubes through circle-to-circle joints. But whether the design has been achieved using the icengineworksTM modeling blocks as it shown in some of these pictures, or by any other method, the general way to use them is the same. Following the sequence of pictures above, the first ring, with the fixed ends of its links is positioned about 1/8" of the edge of the first tube. The first tube is always chosen to be the 'straightest' of the two. The rotation or clocking of the ring is first estimated, but with experience, it will be very easy to be almost dead-on on its final location to create the desired joint that depends on the direction the next section has its arc pointing to. The ring is tightened gently with one hand to conserve the location through friction but also to allow for manually rotated adjustments.
With the first ring semi-tight, the second tube is brought into the second ring, the one that will follow the arc of the joint. the tubes are pushed against each other to eliminate the gap between them and the rings are adjusted so that the joint line sits evenly between the two rings. Then, the rings are rotated until the desired shape of the gapless joint is achieved. By test-fitting the assembly, the perfect location can be found very quickly. At that point, it can be tightened firmly. This process continues for all joints in the assembly. With each added metal section, the proper rotation can be fine tuned by loosening and tightening joints and spinning the tubes; and by test fitting the assembly on its intended location. This process goes on until the resulting assembly achieves the desired shape and fitment and all joint gaps have been eliminated. The next step is to have all joints tack-welded on a single session with absolute confidence. At least two opposing tacks are suggested per joint as usual. The clamping system offers enough spacing between the rings even on the tightest bend combinations to easily place tacks. After the assembly is tacked in place, the clamp rings are loosened and slid out. Then, the assembly joints can be welded completely, in many cases without the need of filler rod because there are no gaps to fill.
Below are some examples of some of the techniques and tips to maximize the benefits of the icengineworksTM tack-weld clamps.

       
Different-size clamps can be combined to create stepped joints. In this case, 1-7/8" to 2" OD steps in a tight layout is shown on the left. Any bend plane, any bend radius are possible. These two pictures show how quickly a metal equivalent is born after modeling the runner in blocks first. No witness lines are required to create an exact version.
    In many cases, a visual approximation is all it takes to get very close to the target shape, with only few quick, minute adjustments following.
The picture on the left shows a joined runner tested on the actual engine for perfect fitment. In the event that further adjustment is required, the clamps can be selectively loosened slightly to allow the manual rotation of the tubes in that joint to find the proper position, a process that takes only a few minutes and is always in real time, that is, with immediate feedback. The tacking comes after, when the assembly is ready.
         
This picture shows the creation of an initial joint between the starter tube and the first section of the runner to allow for the further layout of the runner by anchoring a 1750Series block to the end of it. In this case, with that critical section fixed, we were able to explore different pathways for the rest of the runner without committing (by tacking) the joint to any given location.
         
This picture shows a full runner, all tight and solid waiting to be tack-welded. All joints will be tacked on the same session. The other finished header is shown on the background. With all the metal sections cut and ready, the total time to assemble, clock & adjust and tighten the entire 6-section exhaust header runner, was under 40 minutes. All rotation adjustments and test fitting were done on the engine.
         
         
  See them in action at this youtube link:

http://www.youtube.com/watch?v=fVzX8KMe-lg

 

  
         
  Stay tuned for release schedule per size in the weeks to follow.  
        updated 05/13/08
The icengineworksTM tack-welding clamps are patented. icengineworksTM is a registered trademark of Evolution tuning, Inc. All right reserved.