The framerails are all jig...
The framerails are all jig assembled and welded, with each framerail consisting of three different sections joined in the jig, but we’re getting ahead of ourselves.
In our March 2012 issue we introduced you to our latest project truck, owned by our Tech Center Manager, Jason Scudellari. Adept at all things automotive, Jason decided it was time for a truck of his own and so the search began. Now we’d love to tell you he answered an obscure classified ad in the local newspaper only to find a pristine 1956 Chevrolet truck tucked away under blankets in some little old man’s garage, but that’s not exactly how it went down.
No, this one was located on Craigslist, hauled home for near nothing, and well, sometimes you get what you pay for. The old Chevy had led a long, hard life and beyond the rust, dents, and dings was a ’56 Chevy desperate for repair. That’s the bad news, the good news is, because of strong aftermarket support, all the parts and pieces to bring this truck back to its former glory are readily available. Throw in the abundant amount of talent Jason has and we’re certain this truck will be saved.
After blasting and assessing the sheetmetal, Jason developed a plan for the truck. He wanted a good street driver, one with manners that would make it handle like a new car or better. The plan was the occasional show with some double duty at the autocross. Armed with a clear vision for the truck, it was time to develop the chassis to perform the outlined goals.
The front frame section must be tapered to meet the 6-inch center section of the framerail. A wedge-cut piece of box tubing is welded to the front stub to form the taper.
It soon became clear that, while front and rear suspension and brakes could be installed on the existing frame, the appeal of a whole new chassis and suspension began to make sense. The old frame would require some repairs prior to suspension installation, then the frame would need to be blasted clean, boxed, and the new suspension grafted to the frame. Listing all the parts needed for the job, it became clear that for a bit more money Jason could have a complete new chassis that would be stronger and more rigid than the original. With that in mind Jason placed a call to Brent VanDervort at Fatman Fabrications, and after discussing the project’s objectives, a new chassis was designed for the truck.
The wedge-cut piece is welded...
The wedge-cut piece is welded to the bottom of frame stub to form the taper. The hole in the stub is an access hole for a future body mount.
The chassis would be based on the Fatman Fabrications’ standard replacement frame that is constructed from 0.188-inch wall box tubing. The Mustang II-style front suspension incorporates the tubular control arms that come standard with the frame, and coilover shocks would provide suspension on all four corners. Out back a 9-inch Ford rearend will handle the power, and big Wilwood brakes will provide the stopping power for safe street driving and aggressive autocross braking. Beefy sway bars from Fatman Fabrications are located front and rear for performance handling, and the pedal box will incorporate both the power brake and clutch assembly.
Not only will this all-new chassis perform better than a modified existing frame, it will also speed the project along. Jason stays very busy keeping magazine projects going by day, so shop time for his own project is limited.
After the new chassis was ordered we stopped by the Fatman Fabrications frame shop in Charlotte, North Carolina, to see exactly how a Fatman Fabrications chassis is constructed. It was a true team effort with thanks to the Fatman team of Mike Craig, Josh Layton, Chris Elliot, Pete D’Orta, Scott Hobbs, and Eric Kisiah. We came away impressed and excited about the pending 1956 Chevy pickup project. Follow along with the photos to see what goes into building a top-notch, high-performance replacement chassis. CCT
After grinding the welds down,...
After grinding the welds down, the taper front stub appears to be one piece. Machinist dye has been sprayed to mark the “C’d” area needed for rack-and-pinion clearance.
After scribing the desired...
After scribing the desired radius the piece was carefully cut out on a band saw. Note how the cut goes through the walls of both the main tubing and the added wedge.
A rolled piece of steel fills...
A rolled piece of steel fills the radius perfectly to form the contour over the rack boots.
After cutting the weld down...
After cutting the weld down with a hard disc the finish grinding is done with a small flexible grinding disc. Workmanship on the frame is first class throughout.
Tabs are tack-welded inside...
Tabs are tack-welded inside the main framerail section. These tabs serve two purposes, one as an alignment aid and as an internal “fish plate” to add strength when the butt-weld penetrates the plates.
The rear framerail sections...
The rear framerail sections are formed much like the front stubs. Mandrel-bent pieces have a “C” added for rear axle clearance.
This is the rear section of...
This is the rear section of the framerail being slipped into place over the twin tabs in the main framerail.
Note that both sections of...
Note that both sections of the frame have been ground to a bevel. This gives the weld ample penetrating surface and ensures the wall thickness is not compromised after final grinding.
With all the pieces in the...
With all the pieces in the jig, cross measurements are taken to ensure everything is in the correct position. It pays to double-check even when you are using a frame jig.
After the side rails have...
After the side rails have been welded, the front crossmember is located by the frame jig. Once again, all measurements are double-checked prior to welding.
With the front crossmember...
With the front crossmember tacked in place, our perimeter frame is looking like a full chassis. The tubes extending from the crossmember mount the lower control arms.
Since the rear suspension...
Since the rear suspension will be coilover shocks, a simple box tubing rear crossmember is installed.
The center crossmember incorporates...
The center crossmember incorporates a driveshaft loop and extends past the framerail to accommodate the outboard four-bar brackets. Note the perfect fit of all brackets. The chassis is upside down to ease fabrication on the rotisserie.
Satisfied that the crossmember...
Satisfied that the crossmember is properly located on the frame, the four-bar brackets are welded in place.
The Fatman Fabrications crew...
The Fatman Fabrications crew tack welded the four-bar brackets to the 9-inch Ford housing and now it is time to locate the rear in the frame.
The rear axle housing brackets...
The rear axle housing brackets are two-piece brackets that circle the entire axle tube.
The axle housing is located...
The axle housing is located by installing the four-bars. At this time it is imperative to locate the exact axle centerline. Pinion angle can be dialed in by adjusting the bars.
The four-bars are in place...
The four-bars are in place and the end plate has been tacked in the crossmember. Note the neat and strong box tubing gusset from the framerail to the crossmember.
The brackets for the diagonal...
The brackets for the diagonal bar mount to the four-bar bracket. This bar centers the rear housing and a piece of tubing is cut and welded to the bung in the photo.
Josh Layton measures from...
Josh Layton measures from the axle flange to the outside of the framerail to ensure the axle housing is properly centered.
The bar has been cut and tack...
The bar has been cut and tack welded to center the housing, all the brackets are tack welded in place before any final welding is done.
Now that the rear axle housing...
Now that the rear axle housing has been precisely positioned, the upper shock absorber mount can be located and tack-welded to the framerail. A bar simulates the shock absorber.
After double checking all...
After double checking all locations, Chris Elliot takes the housing back on the bench and TIG welds all the brackets to the housing.
The final piece of the rear...
The final piece of the rear suspension puzzle is locating the sway bars. Coilover shocks and adjustable sway bars should make the truck handle like it’s on rails.
Here we see the finished four-bar...
Here we see the finished four-bar bracket welded and ground to a final finish. The chassis is as good looking as it is strong.
Looking from the rear, the...
Looking from the rear, the sway bar hugs the shape of the rear axle perfectly. This makes for a clean appearance while working wonders for handling.
All the cab and bed bolt holes...
All the cab and bed bolt holes are drilled into the frame with an access hole on the inside framerail.
The crossmember and upper...
The crossmember and upper control arm bracket are now finish-welded in place, so we are ready to mount the Fatman suspension components.
The lower control arm is bolted...
The lower control arm is bolted in place and raised to a perfectly level position to simulate final ride-height geometry. Note that the chassis is again upside down for this installation.
The front sway bar is now...
The front sway bar is now clamped in place and the drop link from the lower control arm to the sway bar is bolted in place.
Measurements ensure that both...
Measurements ensure that both sway bar brackets are the exact distance from the end of the framerail. This prevents any unwanted binding of the bar.
The holes are drilled to locate...
The holes are drilled to locate the sway bar brackets and urethane bushings.
The framerail is tapped to...
The framerail is tapped to accept the bolts; this process is tricky as the threads go through the wedge area so there are two walls inside the rail to tap.
The sway bar is bolted in place and then the upper control arm and spindle are also bolted in place. A locator bar between the control arms simulates the coilover shocks.
Moving toward the center of...
Moving toward the center of the frame, the bracket for the master cylinder is welded in place, the clutch pedal will pivot on the outside of the frame.
The power master cylinder...
The power master cylinder bolts to the pedal bracket and the brake line plumbing can begin.
Josh Layton painstakingly...
Josh Layton painstakingly fit the brake lines tightly to the chassis and crossmember and it shows.
A Wilwood residual valve is...
A Wilwood residual valve is used in the front and rear brake lines. Since the master cylinder is mounted low these valves prevent fluid bleed-back to the master cylinder.
This simple tool is made from...
This simple tool is made from a piece of flat stock steel and serves as a temporary clamp while locating the brake lines.
A small steel tab is welded...
A small steel tab is welded to the chassis to locate steel line where it connects to the braided stainless steel flex hoses.
One of the things we like about the Fatman Fabrications chassis is the rack mounts low on the front crossmember providing extra engine room if needed.
The completed suspension is...
The completed suspension is now installed; Jason will install the coilover shocks and Wilwood brakes after painting the chassis and suspension components.
The new chassis is well designed,...
The new chassis is well designed, strong, and good looking. Fatman Fabrications can supply a pickup truck chassis in several different configurations from a bare frame to a complete roller.
The engine of choice has not...
The engine of choice has not been decided, so a set of motor mounts will be shipped with the frame. The mounts will be located after choosing a small-block, big-block or LS-series motor.