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| Here the mocked up fabricated frame rails are clamped to my welding table. Clamping them solid to a flat plate makes for a sure fire straight rail when done. | This is the reinforcement plate I made for each side at the rear taillight panel. Welding these to the sheetmetal first helps to spread the load of the rails and prevents tearing later on. |
After carefully notching the uprights to fit over the dropped cross member on each side I continued rearward at a 90-degree angle about a foot and then kicked them up at a 45-degree angle to arrive at floor height. Once at floor height I simply cut straight pieces the required length to reach the end of the car. At the tail end of the rails I cut a notch into the ends of them to partially sit on the factory taillight panel. Then I made some reinforcement plates out of 2 in. angle that welded to the sheet metal panel and helps spread the load as opposed to just welding the rails to the sheet metal. Along the way I tack welded every joint and paid particular attention to keeping each side the same as the other.
Once the base rails were made I cut the tack welds loose at the cross member and removed the rails. I have a 1–inch thick surface ground welding table that has come in real handy for various jobs over the years and this was no exception. In order to keep the fabricated frame rails flat and prevent any “draw” from the welding heat it works really good to clamp them to the table at every joint and weld them together. I used my TIG welder as opposed to the MIG simply because I wanted the practice and it makes for a stronger and slightly cleaner weld. The MIG would work fine though if that is all you have. Keep in mind, though, that, according to NHRA rules and common sense, every joint must be reinforced on each side by a plate so that is another advantage of the TIG, no weld bead to grind flat.
Now that the rails were done I slipped them back into the chassis and after a lot of careful measuring I tack welded them into place again at the right width apart and equally spaced in the car. I should mention again that before the rails were tacked into place I referenced my tape marks on the quarter panels to make sure the body was still where it was supposed to be. Now it was starting to look like something and I had a baseline to start working on the fun stuff!
The next project to tackle was the 4-link and before I could weld the chassis brackets in place I needed to be able to install the rear-end housing and wheel/tire assembly in place to decide on the mounting height of the front 4-link chassis brackets. So, I started stripping down the old greasy, rusted up, donor 9-inch Ford housing in preparation for turning it into more “man jewelry”. I’ll save you all the details of how I determined the width of the housing for a later article because I want to cover that in some detail along with selecting axles, brakes, etc.
For now, let’s skip ahead and magically I have a clean, rust-free, narrowed housing with the new Competition Engineering billet ends (#C9506) tack welded in place. I also cut down some stock Ford axles into stubs to mount the wheels. Before I tacked the housing ends on I slipped the Magnum 4-link brackets onto the housing after some final “tuning” with a die grinder to give a nice snug slip fit. There is an inside and outside bracket on each side, so take care to get that right before tacking the housing ends on or DOH!
The Magnum 4 link (#C2028) uses beefy 1 ¼” upper and 1 3/8” lower .095” wall chrome moly tubing for the link arms and threaded weld ends instead of the standard direct threaded tube style, which is considerably weaker. The four pieces of tubing come extra long to allow cutting to fit your application, but the hole pattern on the brackets is designed for a 21-inch radius measured from center of rod end to center of rod end. That is what I am using, so I cut the tubes the appropriate amount and then I used masking tape to temporarily hold the threaded inserts into the tubes for mock-up purposes.
 As of this writing the roll cage is 80% done and here is a sneak peak at the driver’s side. I'm feeling safer already! |
I carefully positioned the housing into the chassis and supported it with jack stands. Then I installed the upper and lower 4-link bars into the housing brackets using the supplied hardware. The kit came with Nyloc nuts for final assembly but also included non-locking nuts specifically for the construction process. I think that is a nice touch and once again demonstrates that the good people at Competition Engineering have done this before.
Here is another tip for you that I learned years ago from a chassis builder and it works wonders. Taking into consideration that the final product will be painted and/or plated upon completion, if you bolt the 4-link brackets down tight against the rod ends during construction the brackets are a certain thickness. After painting and/or plating, the “gap” is smaller and it is often much more difficult to install the bars on final assembly and also when making adjustments. So, by simply installing a .015” valve spring shim on one side of the rod end during construction, it simulates the thickness lost by painting or plating. Works really well and couldn’t be any more simple. Cool, huh?
Next I bolted the front chassis brackets to the link bars and using yet more jack stands to support the weight I placed the chassis brackets up against the fabricated frame rails. I then installed the wheels and tires onto the axle stubs and spent a little time getting the housing centered in the car and the tires centered in the wheel openings. Amazingly my plan came together and the chassis brackets fit just perfect to the rails and the wheelbase was spot on! After a little more fine tuning and general dinking around I determined the height of the chassis brackets in the car and tacked them to the frame rails. This was where it started to get a little more fun because now I could actually see some well-earned progress! Nothing like seeing the big balonies under the car for the first time.
Well, my time this month is up but the pictures are worth a thousand words they say so until next time always remember…There is always hope,
And, when in doubt… DO A WHEELIE!!!
Sources: Moroso, www.moroso.com and Competition Engineering, www.competitionengineering.com