Handling questions

[old guys rule]

Does anyone make solid bushings for sway bar end links? Also, what can you tell me about drag links and panhard bars?

 

[Kern Dog]

Does anyone make solid bushings for sway bar end links? Also, what can you tell me about drag links and panhard bars?

Check this out starting with post # 252.

Re-Rebuilding the 440-493 in a 1970 Charger

 

[old guys rule]

Check this out starting with post # 252.

Re-Rebuilding the 440-493 in a 1970 Charger

 

[old guys rule]

I saw the Ford mod on this site. Unfortunately my b-body is a 63. I sent for the cheapest end link to see if I could figure out if I could make them work. Doesn't look like anything I could handle so I'm going to look around for a good man with a torch I guess. Any suggestions?

 

[Kern Dog]

If you can MIG weld, you can fabricate almost anything. I'm not a great welder but I do okay. In some cases, the majority of the work is the mock-up and trial fitment. The actual welding takes very little time.

 

[493 Mike]

Does anyone make solid bushings for sway bar end links? Also, what can you tell me about drag links and panhard bars?

Polyurethane is close to solid.
Mike

 

[Thrashingcows]

For handling I have found that going with the largest front sway bar you can find and then use poly bushings at every point on the sway bar system.

I have a 68 T/C wagon and when I redid the front suspension I went with all rubber and the stock 15/16 sway bar, it would lean like a drunkin cow when driving through curves. So I ordered a 1.125" Firm feel bar and converted the link and lower control arm ends so i could run simple and readily available poly bushings....now even with the weight of the big old C-body wagon with it's 440 it handles amazing!

 

[68 Sport Satellite]

For handling I have found that going with the largest front sway bar you can find and then use poly bushings at every point on the sway bar system.

I have a 68 T/C wagon and when I redid the front suspension I went with all rubber and the stock 15/16 sway bar, it would lean like a drunkin cow when driving through curves. So I ordered a 1.125" Firm feel bar and converted the link and lower control arm ends so i could run simple and readily available poly bushings....now even with the weight of the big old C-body wagon with it's 440 it handles amazing!

I have a 1-3/8" Hotchkis front sway bar with Poly end link bushings and 3/4" rear sway bar from Firm Feel and I concur!

 

[Kern Dog]

The 1 3/8” bar is hollow.
I’ve had difficulty getting clear answers on the physics of hollow versus solid sway bars. The comparison between the two always requires the hollow bars to have an overall larger diameter than a solid to have equal strength.
The rationale behind them is reduced weight. As the bar twists, the closer to the center matters the least in terms of torsional strength. Still, how thick is the actual steel in the bar? If there is a hollow center that measures 1/4”, is the bar actually equal to an 1 1:8” solid?
I’ve asked this question and never get a straight answer. Supposedly, the gains in outer diameter outweigh the losses of being hollow in the center but what math equation proves that?

 

[68 Sport Satellite]

The 1 3/8” bar is hollow.
I’ve had difficulty getting clear answers on the physics of hollow versus solid sway bars. The comparison between the two always requires the hollow bars to have an overall larger diameter than a solid to have equal strength.
The rationale behind them is reduced weight. As the bar twists, the closer to the center matters the least in terms of torsional strength. Still, how thick is the actual steel in the bar? If there is a hollow center that measures 1/4”, is the bar actually equal to an 1 1:8” solid?
I’ve asked this question and never get a straight answer. Supposedly, the gains in outer diameter outweigh the losses of being hollow in the center but what math equation proves that?

Excellent point KD - yes, the Hotchkis bar is hollow and larger diameter.

I'll share what I know (degree in Materials Science) - bending stiffness of a hollow tube is stiffer than that of a solid bar of the same mass. The reason being that the outer diameter is farther from the center axis. There are many different measures of strength - tensile, compression, torsion, bending, etc.

Here's a good explanation with examples from a physics forum (and they use construction references, so KD can relate to these as can I from my underground gas ditch digger days).
"Another classic example is to fold a sheet into a pleated pattern. The sheet can now hold up weight, where the flat sheet was extremely flimsy. Another similar example... imagine a long board...(IE: a deck board, or 2x6)... if you support it at each end, which way would you lay it so it bends the least when you stand on the mid point... would you lay it flat, or standing up? Intuitively it will bend less if stood on it's end. Similar to the tube vs solid bar example, the board weighs the same....you've only rotated it 90 degrees, but when you stand on it, it bends much less when on end? The math & equations listed above talk about the moment of Inertia (I).... Malverin discussed the distance that the mass is from the neutral axis, and that's the key point here... since the mass of the tube is the same as the mass of the rod, you get a tube with a much larger diameter than the solid rod. Siince the diameter is larger, you have more material further away from the neutral bending axis, so it's stiffer, and bends less (same idea as turning the board on it's end)... same reason why an "I" beam has that shape...the flanges on top and bottom are furthest away from the neutral axis (when in bending... as noted earlier, orientation and load direction are important). The taller you make that "I" beam, the stiffer it will get. If you look at new home construction, they use what are called "engineered beams"... instead of using 2x10 or 2x12 for floor joists, they create a wooden "I" beam, with a top and bottom flange, and often with OSB (chipboard) as the vertical center web...same idea... the material at the top and bottom of the beam give you your bending strength...the material in the middle does very little."
Reference: Why are hollow tubes stronger than full ones.

 

[68 Sport Satellite]

Another great point from the same physics thread - keep in mind the center axis of both solid and hollow tube is neutral.
A solid round bar has a “neutral axis” that, when the bar is bent, is not in compression or tension and so does not contribute to the resistance to bending. If the material near that neutral axis is removed and relocated to the outside surface of the bar, it becomes a tube and is less flexible than the bar of the same mass. Material is being moved from where it gives little or no advantage to the place where it can give a maximum advantage.

Reference: Why are hollow tubes stronger than full ones.

 

[Kern Dog]

That does make sense. Thank you.