Ford Model A Frame - Boxing Clever

Though I'm not sure what the make is of the bodyshell I'll be using, I did know the rear panel was angled by 18 degrees, so I planned the kickup to match. I planned to start the kickup, or Z, 14 inches from the rear crossmember, and marked the chassis and jig accordingly, then clamped a length of 3x1 3/4 inch x 3/16 wall thickness box section at this mark at an 18-degree angle. Knowing where the front of the box section intersected the chassis at the 14-inch mark, I could then mark the point where the rear of the box section intersected the chassis at its underside. Scribing a line between these two points gave me my cut line for both the chassis 'rail and the box section.

Here's where I had to do a little math. The wishbone mounting points had been 4 1/2 inches below the chassis 'rails and I wanted the 'bones to remain parallel with the 'rails, and mount through them. With the 'rails 4 inches high, and wanting the mounts at their midpoint, I added 2 inches (half the height of the 'rails) to the 4 1/2-inch measurement, meaning the kickup had to be 6 1/2 inches high. Using a set square I transposed this vertical measurement to the box section and marked it accordingly. I now knew how long to cut the kickup sections, which worked out very close to 7 inches.

Not possessing a protracting set square, I cut this section of angle at the same angle as that determined in caption 13, to ensure all my cuts would be identical.

Next, I needed a way to raise the rear section of the chassis by exactly 6 1/2 inches once I cut it from the main chassis. These 90-degree plates did the trick. As you will see in the next picture, their lower-angled section sat atop the jig. I clamped them to the 'rails and marked a reference line 6 1/2 inches higher (arrow).

Here you can see the 90-degree angled brackets on the jig. With everything clamped in place I cut through the chassis 'rail at the predetermined angle. Note I also added an extra crossbrace to support the rear 'rails once they were removed.

I was focusing so intently on ensuring everything was square once I'd cut the rear of the chassis off that I probably missed a couple of steps with the camera! Once the rear section was removed I moved it up the angled brackets by 6 1/2 inches and re-clamped it, then fabricated a temporary rear support for the chassis crossmember. With everything level in all directions, I tacked the kickup sections in place, aligning them with the outer faces of the chassis 'rails.

Once the kickup sections were fully welded I used the set square to transpose the length of the chassis stretch onto the jig, which worked out to be 2 3/4 inches. This allowed me to move the wishbone mount locations rearward by a similar amount.

Some may call me a pack rat or hoarder, since I rarely throw anything away, but here's why. These tapered bungs are actually the cross steering tie-rod parts of early Ford spindles that I cut off when they were no longer required in hot rod applications with drag link steering. A pair of them made perfect wishbone mounts as they use Ford tie-rod ends. With holes drilled through the outer 'rails at the now-determined location, the bungs were welded inside the chassis. Of course you could buy tapered wishbone mounts too!

This is the laser-cut Model A chassis boxing kit sold by Dagel's Street Rods. Sure, you can cut these out yourself, but seriously, why bother when the hard work has been done for you? The shorter two of the four are for boxing the rear of the 'rails, and I welded them in place first.

Dagel's boxing plates are cut slightly smaller than the outside-to-outside vertical measurement of the 'rails. The stepped area will be filled with weld, ensuring all the strength is not ground away when cleaning up the welds later. The edges of the 'rails were ground clean before welding commenced.

Model A chassis have a bend roughly halfway down their length, and the rear boxing plates go past this bend. Once the rear section was clamped in place, this was easily pulled around the bend using a C-clamp.

Before I welded the boxing plates to the chassis, I cut a couple of 2-inch holes in the plates to allow access to the wishbone mounts. Later, these will have tubes welded inside them.

There are four points to note here, namely the access hole for the tie-rod end nut, the front part of the boxing plate pulled around the bend in the chassis 'rail, and the excess length of plate still in place at the rear (remember the frame was Z'd and so the plates are too long for this section now). And the fourth point? You can never have enough C-clamps. Note the plates are only tacked for now at roughly 4-inch intervals.

Here's the righthand framerail with the boxing plates tacked in place. I trimmed approximately 6 inches from the front of the forward plates, allowing myself room to remove the front crossmember should I decide to later. Dagel's supplies the plates' oversize to allow for various crossmembers.

I ground an angle on the edges of the boxing plates where they meet to ensure decent weld penetration.

Though I will leave the chassis with the boxing plates tacked in place this month, I finish welded and ground a short section to show how neat the joint can look, thanks to Dagel's stepped design, which doesn't compromise strength but allows the weld to be dressed for appearance.

Here's why the kickup sections were fabbed from 4x1 3/4-inch box. With the long boxing plates trimmed and welded, they overlap the box section to provide a stronger joint than a mere butt weld. The section I cut off was then used to box the rearmost section of the chassis. The recess will be filled with a section of 3/16-inch plate, so once everything's welded and dressed, this whole area will appear to be 4x2-inch box section.

At this time I'm undecided as the outcome of the front crossmember. If I retain the stocker, I'll fill the gap shown here and weld the boxing plates to the crossmember.

Before I could weld the left-hand front boxing plate in place, the 'rail needed a little work. I don't know if it's because the steering box mounts here, but every Model A frame I've owned has been twisted along this side. This one was bent at the forward body mounting hole and just forward of where the 'rail starts to taper (arrows). The top of the 'rail also leaned inwards at the point of the forward bend.

Don't panic, it's only metal! I cut across the top of the 'rail at the point of both bends, as well as cutting the frame free from the mount on the jig at this point. Clamping the 'rail to a straight section of thick walled box section pulled it back into shape, before the slits I'd cut in the top were welded up and the jig mount was re-welded. The boxing plate could now be fitted.

Still welded to the jig, here's the chassis with the boxing plates tacked in place and the rear kickup completed. It'll stay on the jig/dolly until the X-member is welded in.