There is no doubt that traditional-appearing rods, and all of their permutations, have had a big impact on the world of hot rodding these past few years. There are several styling cues incorporated into the design of these vehicles, from tall, thin wheels and non-metallic paint jobs to a general lack of fenders-they all say "vintage."
One design element found on some of these rods, the quarter-elliptic spring, has been around for a very long time as builders have been using the concept on cars for decades (the '60 bugeye Sprite had them mounted to the rear end), WWII-era Panzer tanks had 'em, and even earlier incarnations were used on the front wheels of Excelsior and Indian motorcycles-as far back as the late teens.
But there is something about hanging the suspension out in front of a car that makes it look racey. And we don't mean that in the quarter mile sense, but rather on the board tracks of the '20s; graceful but imminently dangerous one-man modifieds.
Here's what a lot of people...
Here's what a lot of people already have: a stock Model A suspension set-up. The major players are a stock (albeit drilled) I-beam axle, pre-split wishbones, and a stock multi-leaf transverse-mounted spring.
The look has come full circle and embraced by rodders nowadays, too. Jason Grimes, who runs The Garage in Lebanon Junction (about 30 miles south of Louisville), Kentucky, has been using them on some of his creations of late, so Street Rodder stopped by his shop to watch him radically lower a stock Model A chassis by converting the suspension over to a quarter-elliptic layout of his own design.
It turns out this method is a cheap and simple way to get a lot of drop, keep a respectable amount of ride comfort, and still have a fair amount of adjustability in the suspension.
The process isn't insurmountable, mostly because one spring-maker, POSIES', has a quarter-elliptic kit that you can outfit to any project that you desire. And, as an added benefit, POSIES' ElliptaSlide Spring Kit comes with your choice of either light or heavy spring rates, and Jason chose the heavy rate kit (#QK2) for this configuration.
The real work was in lopping off the front of the A chassis, removing the front crossmember, cutting up a stock A wishbone to make a pair of split 'bones, then drilling out an axle to fit some of the parts. Like we said, it isn't a cakewalk; you do have to pay attention, especially because what you're doing will certainly affect the alignment and placement of your wheels, let alone dramatically change the design and working of its suspension. So follow along and see how they do it in the Grimes' Garage.
With the chassis set up on...
With the chassis set up on jackstands at what would be ride height for a stock Model A, the measurements show 8.5 inches from the ground to the bottom of the axle but, more importantly, 16.5 inches to the bottom of the crossmember.
With some crossbracing tacked...
With some crossbracing tacked to the chassis to keep it from flexing out of shape, the rivets that hold the crossmember in place are cut off with the torch, and then popped out with a punch and hammer. Jason also marked the centerline of the crossmember as that will be where the next cuts will be made.
The stock crossmember is knocked...
The stock crossmember is knocked out of the frame and Jason marks the frame with the outside diameter of the new crossmember, made from 2.5-inch .125 straight tubing.
After using the plasma cutter...
After using the plasma cutter to cut both frame ends, Jason cleans up the edges with a disc grinder.
With the new crossmember cut...
With the new crossmember cut to fit, Jason then welds it in place.
Jason makes some templates...
Jason makes some templates from cardboard to see how the boxing plates will fit against the new, round crossmember.
The stock spring perch is...
The stock spring perch is on the right. On the left is the modified perch with the ends cut off, because Jason won't be using a transverse-mounted spring.
The stock wishbone is then...
The stock wishbone is then marked and cut to create a pair of split 'bones. Jason then adds a threaded sleeve to the ends and welds it in place.
To finish up the radius rod...
To finish up the radius rod Jason adds a threaded tie rod to its new, threaded end.
The new radius rods (made...
The new radius rods (made from the old 'bones) and axle are set in place.
The rear mounts from Speedway...
The rear mounts from Speedway Motors for the radius rods are tacked in place.
Jason lines up both the centerline...
Jason lines up both the centerline of the crossmember with the centerline of the axle.
Using a common hole found...
Using a common hole found on each side of the frame, Jason squares the axle to the frame by making sure this measurement is the same on each side of the frame. The final adjustment will be made when the frontend assembly is completed and the wheels are mounted.
The ElliptaSlide front suspension...
The ElliptaSlide front suspension kit from POSIES is laid out to show its pieces: the quarter-elliptic springs, shackles, and perch mounting bracket.
Satisfied that everything...
Satisfied that everything is square, Jason welds the radius rod brackets in place.
The quarter-elliptics and...
The quarter-elliptics and mounting bracket are held up to the frame to determine where it will be mounted. This also allows Jason to determine where the new spring perch will come off the axle while keeping in mind the shackle should be at 45-degrees.
After figuring out where the...
After figuring out where the new perch mount will go, Jason drills out the axle, then adds a small spacer to it on the backside so the new spring perch will sit flush.
The quarter-elliptic's new...
The quarter-elliptic's new perch is inserted against the boss and tightened down. You can also see how the old, cut-down spring perch fits inside the radius end.
With the springs in place,...
With the springs in place, it's time to weld up the mounting brackets.
A close-up shows what how...
A close-up shows what how the set screw keeps pressure on the top spring, holding everything in place. Using the bracket as a guide for his drill, Jason then drilled out the framerail for the spring's rear mounting bolt.
The completed suspension assembly,...
The completed suspension assembly, with the quarter-elliptics installed with a stock I-beam and split 'bones. Since the axle wasn't changed during the build process, it's still 8.5 inches off the ground, but you can lower it further with a dropped I-beam axle. But the big difference is where the chassis ended up-more than 7 inches lower than what it rolled in with. After the engine, radiator, and headlights are mounted, a Panhard bar will be added (making sure it will clear the other components).