Splitting the wishbone for a speedster

[Reno Speedster]

I have abandoned the stock front end wishbone for my 26 speedster and gone with radius arms between the lowering brackets and the frame (see the attached photos for some shots of work in progress). I have a ball joint at the frame but the connection to the drop brackets is solid. This is consistent with what I see in the period speed books (Secrets of speed and the fast ford handbook) but I am wondering about the forces generated by this type of rigidity. In modern cars, they use Heim joints to allow everything to move freely, but that is not period. Am I over thinking this?
What kind of experience have folks had with split wishbones on speedsters?

To be clear, abandoning the wishbone is a done deal, so keeping the stock setup is not an option.

[pete eastwood]

You are OK with that setup. The hot rodders have been doing it that way for years.
I've been in the hot rod building profession for over 50 years.

[Kevin Pharis]

Not too much different than most other speedsters. As Pete says, will work OK. Couple things to consider tho. Be sure to index the Model A steering arms against a machined square shoulder on the spindle. Will need to weld up the T spindles to provide the register similar to the Model A. Without, the steering arms will rotate while driving causing the toe alignment to wander… kinda sketchy! Also, try to keep your drag link parallel to and similar in length to the radius rod. Bump steer is bad enough on any straight axle car, best to prevent when possible

[Reno Speedster]

Thanks for the tips. The drag link is parallel to and close to inline with the radius rod. Both the radius rods and the drag link are pretty long, which should help with bump steer. I will index the A steering arms and lock them in mechanically and with lock tight to the spindles to keep them from twisting.

[kmatt2]

You are going to need a panhard bar or at least lock one spring shackle to keep the axle centered from side to side. For a dirt track car lock the right hand shackle if you go with a locked shackle.

[Craig Leach]

Hi Morgan,
Nice work, is the bolts on the radius rods going to allow for caster adjustment?
Craig.

[Dan McEachern]

How much ground clearance do you have with the front crossmember and the Laurel brackets- its gonna be pretty low.

[TrentB]

“ I've been in the hot rod building profession for over 50 years.”

Having seen some of Pete Eastwood’s creations, I’d say this was an understatement.

[Don]

Make sure your radius rods are parallel to the ground. This usually means lowering the rear attachment. If the angle is too much, every time the front axle goes up and down, it always goes forward and aft. The for and aft distance causing wear and resistance to bushings is minimized if the radius rods are parallel to the ground.

[Reno Speedster]

Hi Morgan,
Nice work, is the bolts on the radius rods going to allow for caster adjustment?
Craig.

I machined caster into the Laurel style brackets when I made them (7 degrees if I recall correctly). Here is a couple of pictures of them in the making. I machined them out of blocks of 1018.

By the way, for those that might ask, Allen cap screws are period. I saw a 1924 add for them, so used them for the axle bolts.

[Reno Speedster]

How much ground clearance do you have with the front crossmember and the Laurel brackets- its gonna be pretty low.

Yeah, it’s going to be low. Speed bumps won’t be my friend…

[Kevin Pharis]

By the way, for those that might ask, Allen cap screws are period. I saw a 1924 add for them, so used them for the axle bolts.

Nice work on the Laurel brackets! Curious where you found the 11/16” bolts tho…? I’ve made a few sets, great project to use up those old old axle shafts

[Reno Speedster]

I could not find the bolts I needed so I cut down long shank 3/4 inch cap screws to the correct overall length, turned them down to closely fit the axle and brackets, then cut threads on the ends. They came out well.

I made the radius rods, which bolt to the side of the bracket and but up against the outside shoulder. This way, backwards thrust is not placed on the mounting bolts alone.

Here are the brackets I made for the pivot of the radius rods. As you can see, they mount on the frame at the rear engine mount using existing holes and hold the firewall brackets on.

I have made, modified, or rebuilt a lot of parts for the car and there are more to go. I am working towards it being a rolling chassis. Then I can finish the mahogany skiff body, then start work on the aluminum hood and grill and sort out fenders.

[Kevin Pharis]

Lookin good!

[Reno Speedster]

Thanks. Since I am posting pictures of modifications, here are some shots of the modified timing and throttle fixture I made for the custom steering column. I am using a modified Ross A steering box (which is similar to aftermarket boxes sold in period for racing) but did not want to use the A column. I also wanted to keep the T controls. So I made a custom column and mounts (top and bottom), then modified an original brass fixture I had to fit a new round center. I silver soldered the new and old parts together and fitted the unit to the top of the custom steering column. Here are a couple of shots of the modification in progress and fitted on the column. I would like to nickel plate it before I am done. I want to engrave “Oil” with a little arrow pointing to the screw on the top of the fixture (shown in one of the pictures) as this is the oil hole for the top bushing of the steering column.