Ron Werderitsch has been driving his '30 Model A coupe since he was a high school student. In the decades since then, he has maintained and upgraded the car slightly, but kept it traditional and mostly stock. The original engine has been replaced-not with a V-8 but with a souped-up '29 five-bearing four-banger, backed by a '39 Toploader and 3.54:1 rearend.
It's a stout and desirable engine, but kept breaking at the crank. Several shops had misdiagnosed the problem as lying somewhere in the engine itself.
Chad Blundell at Blundell Speed & Machine in Orange, California, figured out that the only thing wrong with the engine was that it was making a lot of power. When Ron dropped the clutch on the high-geared rearend with no posi, it was flexing the frame, straining the engine, and tearing up the engine mounts.
The Model A's simple frames were never known for their strength, which is one of the reasons why Model A owners frequently replace them with '32 'rails or aftermarket frames. In this case, however, Ron wanted to retain the heritage of the car he's been driving for so long. The body hadn't been off the frame since one of Henry Ford's assembly line workers introduced the two of them. The 'rails were in great shape, but a little tired after 77 years. So instead of going for an all new frame, he took the traditional approach-improving what was already there. In this case, that meant reinforcing the 'rails with boxing plates; closing the open side of the 'rails will greatly resist flexing.
Boxing plates can be found in various gauge sizes, but it's recommended that 10-gauge be used for V-8 engine applications, at least on the front half of the car where there is more weight. Here Chad used 10-gauge front and rear, which is stout enough to handle a small-block and will be more than adequate for Ron's built-up 'banger.
Now that the 'rails are boxed, Chad will continue by adding an X-member to the frame, fabricating new engine and trans mounts, and replacing the body mounting wood. When the body goes back on, it will be on a seriously stout frame.
After the 'rails are boxed,...
After the 'rails are boxed, there will be no way to reach the nuts that tighten the body mount bolts, so cage nuts (retainer weld nuts floating in square housings) were welded to the inside upper edge of the 'rails. This will eliminate the need to cut a hole in the boxing plate. In addition, the floating nuts allow some flexibility when lining up the fenders and the body.
Chad started by removing the...
Chad started by removing the front and rear suspensions and sandblasting the frame to remove the decades of dirt and rust that would contaminate the weld. He welded a steel bridge to the frame to locate the engine, and was in the process of removing the stock center crossmember. The bridge had been tacked to the engine block to hold it in the correct position when the mounts were removed. Engine position (left to right, height, and angle) is critical for proper drivetrain geometry. The engine and transmission were removed once the proper locations for the new motor mounts were established.
Chad confirmed which holes...
Chad confirmed which holes in the frame were the body mounting holes by measuring the body and then marking the frame. Each side will require two 1/2-13 nuts for the body (the stock size is 7/16, but 1/2-inch cage nuts work fine), one 3/8-24 nut for the front cowl mount, and three 1/4-20 nuts for each fender. The mounting bolts on the outboard side of the frame don't need cage nuts.
The frame was flipped over...
The frame was flipped over to make it easier to MIG weld the cage nuts. The bolts held the nuts in place.
The insides of the 'rails...
The insides of the 'rails were finished with 3M Weld-Thru II weldable primer (PN 05917) to protect the metal from corrosion. Each boxing plate was cleaned with acetone lacquer thinner to remove any factory coating, and given a shot of weldable primer on the inside surface.
Before welding in the boxing...
Before welding in the boxing plates, Chad and Greg Gillaspy took measurements corner to corner, and from the center of the front crossmember to the rear corners of the 'rails to check that the frame was square and the crossmembers parallel. They were; the dimensions on this frame were within 1/8-inch. Pretty good.
The edges of the sandblasted...
The edges of the sandblasted surfaces were ground smooth to take the weld better.
The boxing plates typically...
The boxing plates typically require some trimming for length. On the front plates, Chad measured forward from the point where the 'rails start to taper upward toward the front. A few inches will have to be removed from the front of these plates. And since Ron's Model A retains the original front crossmember, the plates will also need to be cut and notched to fit around the narrow pan at the rear of the front crossmember. After careful measurements, this plate was ready to be cut.
With the first boxing plate...
With the first boxing plate cut and clamped into position, Chad began tack welding it into place. He did some additional MIG welding in the front where the plate meets the crossmember to provide some extra structure in the gaps. Since the 'rails had gotten out of shape over the years, some hammer and dolly work was required to make the plates fit perfectly.
The rivets had loosened at...
The rivets had loosened at the front crossmember after more than 75 years of use, so Chad TIG welded them where the 'rails meet the crossmember.
A portion of the boxing plate...
A portion of the boxing plate on the front driver side of the frame needed to be removed to accommodate the steering box.
On the outside of the 'rails,...
On the outside of the 'rails, Chad scribed a line at the outside perimeter of the mounting holes, and continued it over the top of the frame. On the boxing plate, cut lines were marked 3/8-inch on the outside of each mounting hole location to allow room for the steering box flange.
Rather than cut straight vertical...
Rather than cut straight vertical lines, Greg cut C-notches, which look better and still allow the steering box to fit perfectly.
With the front boxing plates...
With the front boxing plates tacked in place, the rear plates were positioned. The front of the rear plates overlapped the front plates by approximately 1 3/4-inch and needed to be trimmed.
Instead of butting the front...
Instead of butting the front and rear plates together, Chad left a 1/16-inch gap, which will provide a space for the weld to penetrate into and where it won't get ground off. Also, look closely at the point where the plate meets the upper portion of the 'rail (arrow). The plate wasn't pressed flush into the frame, but meets it corner to corner. This provides a little right-angle chamfer for the weld.
The 'rails were TIG welded;...
The 'rails were TIG welded; afterward, they will be ground and eventually painted. When TIG welding the frame, it's not recommended to work your way down the 'rails from one end to another, but to keep moving from spot to spot around the frame. This will prevent the 'rails from getting too hot and possibly twisting or going out of square.
Cool Framehorn CoversThe framehorns...
Cool Framehorn CoversThe framehorns will not be boxed on this Model A, but they may be on yours. If so, take a look at these great-looking framehorn covers from the Ionia Hot Rod Shop, available for both weld-in and bolt-in spreader bar styles. According to Matt Lesky, up in Ionia, both styles are offered for most applications. "All of the frame manufacturers-from Ford itself to Dearborn to Lobeck's to the rest of the aftermarket-are a little different. This is a universal part you can grind to fit your particular frame. They are designed long to fit stock or forward locations. You can trim the back to fit against the crossmember and grind the upper and lower edges to fit the contour of the frame-and either flush mount them or send them in." For more information, contact Matt or Dennis at Ionia Hot Rod Shop at (616) 527-6051.