Double dip tube axle on hairpins with quarter ellipticals...

Anyone foresee serious issues?

I know that a lot of people say not to run pins with a tube, but I also have seen lots of people on here say they have been for years with no issue.

Here's a photoshop I did of the idea. Obviously not to scale or suuuuper precise, but you get the idea.



That's kinda what I'm thinking.

Also, should I need a panhard bar on that kind of setup? I'm more than likely going to be doing cowl steering.

Here's a better pic of the axle on someone else's vehicle from the hamb:



Any ideas or thoughts welcome.

TIA

 

Wow guys.... 30 views and no one has any idea.

I'd almost say that the forum is getting less and less tech and more and more "what color wheels".

haha

 

I would think you don't need a panhard with the quarter elliptics. There are a million and two opinions as far as hairpins and tube axles, as you noted.

 

Thanks for the reply Richard.

I was ***uming that the paralell mounted quarter springs would kill any lateral movement on the axle... but my real concearn was the shackles. I mean, I'm 99% sure I'd still run shackles with this setup, but will they allow even a little sway?

 

Something's gotta give. I wouldn't take chances with the front suspension. Either go 4 bar or beam axle. Before I come off sounding like a know it all (which I'm definately not), I'll just tell you what I see and understand. Others can correct me or clarify.

Picture it like this. One wheel goes over a bump. A beam axle will twist and absorb some of this along with the hair pin. The tube axle is much more rigid and is not meant to twist. Instead, the brackets welded to it will take all that force twisting in a different manner. Your weakest link would eventually fail...eventually. Most likely that would be at one of the welds or the yokes on the haripin. You'd be better off with heim joints, but that still doesn't fix all of it. There is going to be pull on the hairpin where it mounts, not just twist. You might get away with it for years, but that doesn't mean anything if those cars were just driven on mostly smooth roads and not really driven daily. How many miles to they log over those years?

Not to mention your Ackerman is going to be off if your run the tie bar up front. It would appear that you have enough clearance to run it behind the axle. It doesn't have to be a straight bar. You can bend it and make it clear the bones and spring if you need to as long as its stout.

 

That's the stuff I was talking about that I've already read, and the responses from people who actually own cars with this kind of setup say that they've never really had a problem.

I don't want to run a 4 link... I think they look ridiculous on an open rod.

***uming the pins are long enough, which can be whatever length I need since I'm building them, I don't really foresee any reason why this would be some god foresaken deadly combination.

Could anyone that owns a pinned/tube front end please give some insight?

Oh, and I had no intention of running the tie up front. I prefer a car to be driveable.

 

Yes, but not the way they are intended. The only sway allowed would be limited to the flexibility of the bushings, the shackles themselves and stress on the springs which might make them fan out a little.

I'm just seeing stress put on a lot of components not intended to take it the way they are designed. Twisting motions that just shouldn't be put on things.

 

I'm with Frank i'm afraid.

 

No problems with shackles,look at all the cars and trucks
running parallel leafs with no Panhard bar.

 

So, if the "stress put on components not meant for it" were a factor, wouldn't it cause all 1/4 ellipitical setups to fail? I mean, they'd all fan, wouldn't they? Hmm...

 

I'm sure you will get it from both sides. Sure looks cool, though. Are you doing it this way because you have the parts, or because of the looks? Split bones or a beam would cure it, one way or the other.

 

I've got the axle, and want to run it cause it's a nice look and it's definitely different.

I wouldn't be super opposed to running split bones on there, but I was told that split bones don't work on this mopar axle.

If there's a way to do that, I'd just run split bones instead....

 

Maybe weld some round stock with a hole the same size as the kingpin hole on a Ford axle, and mount the bones like that? Was that a parallel leaf axle originally?

 

I *think* the mopar was actually two longetudinal leafs.

I just really don't want a beam axle. They're kinda overdone, and I know, they are traditional.... I got this setup for $70.00 from a friend and I'm dead set on running it. haha

Aren't split bones on a tube axle even worse safety wise and engineering wise than a set of hairpins?

 

i don't see why split bones would be any better?the problem is the force on whatever holds the axle to the frame right? a 4 link works because it lets one end of the axle move up and down independant from the other.

someone did a real slick setup that had the axle cut in the center with a joint to allow it to twist... looked cool and clever. I can't remember who it was?

 

Tube axle with UN-SPLIT bones, no problems.

 

also, think about the stress when your car leans in the corners.. i imagine that's a bigger issue than hitting a bump.. the whole thing is going to want to twist.

 

Fatman Vintage IFS:

http://www.fatmanfab.com/catalogpage.php?page=2

 

the photo shop image... i have been working on the same setup...It looks like it will work great..i plan to use 4 link bushings at the axel not notclevises somthing like this

 

right! lifting one corner of a triangle is easier than lifting one corner of a square.. something has to flex with the square.

 

See... NOW we're talking!



Some poly sleeves at that end and a poly sleeve at the frame...

 

What I built.
The current owner says it handles like a go cart.
No sway bar.
Fred

 

Is that just using the 1/4 elliptical as a lower locater with a tube on the top?

Kinda using the spring as the bottom rods of a 4 link?

 

I will not claim to be an expert either. However, I have talked on the phone with a few maufacturers who told me the set up is workable. I don't think it's ideal, but a lot like the Fat Man IFS, it works because these cars have a limited drive time combined with limited front suspension travel. I was also told hairpins themselves would allow for similar flex to a beam axle. I for one agree with those who don't feel comfortable allowing anything to flex.

 

EVERYTHING flexes some, yes? If there is no flex, things tend to break, no?

 

You have a point. Not sure you even need the shackles the more I think about it. The pic lakesmod posted looks trustworthy.

 

Talked to a guy who does tech stuff for T bucket front ends and he says NO SHACKLES! So apparently they aren't necessary.

 

I'm running a tube with cross spring and hairpins, I can jack one side of the axle up almost a foot before the other side tries to come up with it. I really just can't remember running over a foot tall obstical with one tire ever.

 

Yes, I won't argue that point. I was leaning more towards staying away from letting supposed non flexing components do the flexing. Trying to let movable joints take care of the motion.

 

The idea that hairpins don't flex is wrong though.

Hairpins are designed TO flex. That's part of what they do.