Full fendered model A Gasser build thread

I hear what your'e saying and their good points. I'd also prefer them pinched in the front myself, but I've witnessed spindly little Speedway hairpins on T buckets (Parallel) that were driven to hell and back without incident. We also don't Know much about the construction of the bars in question. They may even be be Chromoly for all we know. I'm not just trying to push your ****ons, just give my point of view so ease off on the CAPS please.

 

No sweat Landseaandair.

Many guys here copy what they see because it is "traditional" or "looks cool" or is the way others have done it since the dinosaurs, without understanding the really bad engineering.

Henry Ford was a real smart guy, and he designed it right. Some of the changes Hot Rodders traditionally make away from the original are not quite so smart. These ladder bar things work on a drag strip, but high mileage street use spell big trouble.

I will tell you one thing for sure, here in Australia, if you fronted up for a set of number plates with something like that, you would be told no deal . Fix it and come back.

What each of us puts on our Rod is a very personal thing, but knowing that it is going to crack the welds, be rewelded, maybe several times, and crack again, without at least mentioning it is really bad Karma.......

I am not some suspension design Nazi, just a guy that has learned the very hard way from a lot of mistakes.

 

I respect your opinions. Sounds like you guys have some pretty tough enforcement down their. We probably look like a bunch of whiners since all we really have to complain about is how to get our ***le issues straight.

 

Yup it is really tough here to get full road registration.

Every stage of construction has to be approved by an engineer, and he takes full personal legal responsibility for any design flaws that might result in an accident.

But our Rods are probably the best and safest anywhere in the World.
No rusted out rat rods with open exhausts and zero ground clearance here.

 

Wow, I guess there are some pluses. Us 'Mercans ain't ready to give it up yet though! Cue Lee Greenwood.

 

America is still Hot rod Heaven, and very affordable too.

You guys think 10K to 15K for a second hand rod is reasonable.

Here the same thing is more like 40K to 65K for something fairly similar, and US and Australian dollars are now worth exactly the same.
You might think there would be a great business importing US Rods into Australia, but we are not allowed to.
Americans just don't realize for example, how the Europeans are paying ten dollars per gallon for gas, and have been for many years.

Things are very different overseas to what you guys just take for granted.

 

Ouch, how would it work if you were stock restoring a model A, and what about having a bone stocker registered and insured then tear it apart to "rod", could you just keep your reg without going through all that?

The rear ladder bars are 1" OD 3/16 wall seamless DOM tubing with a 1/4" gusset in middle, and the brackets on the rearend and frame are 3/16 double shear and it is all heliarc welded by a profesional with 5/8 grd 8 bolts.

The rear ladder bars are 45" long with poly ends on the rear end wich should handle a little more movement. landseaandair, you are right about if the rearend brackets w****d around the rear it would be stronger but it is a light truck with a pretty stock 283. I have seen many cars with realitivly built engines run this set up such as the '32 on page one from the ch***is shop with many miles on it. I really dont see a diffrence than a front end with a tube axle and hairpins that is ok. I dont undersatand why the rear would also have to pivot if the front suspention does also, when you are going on a drive way at a angle the front sus. pivots and alows the rear crossmember to be parellel to the rear end so it should be able to pivot also when the rear end is going onto the angle and allow the whole car to pivot on the front sus.

 

If you stock restored a Model A in australia, you would join a club and get club road registration.
That gives you special number plates, and allows you to drive your Model A to and from sponsored events.

It does not matter how strong you make your ladder bars, the problem of stress and metal fatigue still remains.
And you are absolutely correct, split front bones and hairpins suffer from exactly the same problem as rear ladder bars.

The only sound way to do this, is with a four bar, and a horizontal location device such as a panhard bar or maybe a Watts linkage.
You will instantly see, that a four bar allows each rear (or front) wheel to rise and fall without trying to twist the beam axle.
The original Henry Ford front and rear ball joint location allowed full beam axle movement without twisting either beam axle. Splitting the bones, at front or rear completely screws that up, and stresses everything in a very different way.

 

Only sound way is to pick up your catalog and order premade parts. Ordering four bar suspension parts is our real foundation on how to build a hot rod ch***is. Forget all you might have learned.

 

Nothing at all wrong with home brewed parts, as long as those parts are sensibly designed and fabricated with a reasonable level of skill.

But if you have to pay someone else to make those parts because you don't have either the tooling, machining, polishing, plating, or welding skills, a professional store bought Hot Rod part may actually be a great deal.

 

Here's some inspiration for your g***er pickup...

 

Trad 27, the forces on the front axle locators like hairpins or wishbones, whether it be on a tube axle or an I-beam axle are push/pull as the suspension compresses or unloads, there's no real shearing force being applied there. As the frame rolls on the suspension, that torsional flexing is transferred back to the mounting point on the frame...which is best taken care of by using a heavy tie-rod end...lots of articulation.

The rear ladder bars can be exerting torsional flex, push/pulling force, and shearing force at the frame mounts all at the same time.

A properly designed ladder bar setup acts like a torque arm at the same time it locates the axle. So when you hit it, the forces are evenly balanced at the rear axle, and the arms themselves want to lift up at the frame mounting points. Because they aren't going up or down, the forces get transfered back to the rear end, pulling it downwards toward the asphalt...hence the digging in of the tires and the launching of the hotrod.

So if you're going straight, no issues at all. But...on the street, the rear frame of the car will roll, putting the same torsional flexing force on the frame mounting points as it does at the front, but combined with some of that torque force from the rearend pushing the car...those mounts are constantly under some level of torquing force. All that gets exaggerated if you're accellerating out of turns alot and stuff like that.

So, like warpspeed said, using the arms straight out is essentially making your ladder bars into an anti-roll bar set up as well.....but that's only going to happen once your heim joints or urathane bushings get maxed out in their articulation. It won't happen under regular driving, but with aggressive driving you will push them to their max, transferring twisting torsional force into your ladder bars and back to your rear axle.

There's a reason why Ford himself, mostly all aftermarket frame manufacturers, and the designers of the Pete n Jakes ladder bars made them meet closer together in the middle...that's the reason.

I'm pretty sure you can use that setup the way it is, just make sure you use some sort of sway bar or anti-roll set up as well. You see alot of street/strip g***er style cars using straight torque arms, or ladder bars, usually with parallel leafs for suspension and a sway bar.

I think the key to long life for your setup is to add a heavy duty sway bar.

Correct me if I'm wrong guys! I'm just using my basic knowledge and common sense here! haha

-Steve

 

That is certainly true.
You can split the bones and replace the original single ball joint with a pair of compliant bushings, as long as they remain fairly close together.
That allows you to lower your sump/gearbox/driveshaft right through where the original central ball joint was supposed to be.
That will work fine, and it largely maintains the original look.

 

What do you think about him using it the way it is now...out straight...as long as he adds a sway bar in the rear?

Would that fix, or further minimize the issues we're talking about?

 

And just to clarify, the issue with running an I-beam axle up front and splitting the original bones and moving the mounting points outwards to the framerails, or using hairpins in the same fashion, is not an issue at all.

Most of the torsional flex is handled by the natural, and intended, twisting of the I-beam itself, anything else is handled by the articulation of the tierod end or heim or whatever you use at the frame mounting point. So unless you're using your hotrod as a rock-crawler on the weekends, you're guaranteed safe for life.

That's a tried, tested and true setup that's not really up for engineering debate.

And regardless of what you believe Henry had in mind, the I-beam axles were made so they can twist without breaking...ever...

 

4 links became widely used and popular around the time that dropped hotrod tube axles started being produced....because they don't twist or absorb force.

Even with the forces you're talking about, lots of guys still run split wishbones with tube axles, use a heavy duty tierod end at the frame mounting point and never ever have a problem.

 

Here is an article of bent ladders on A. The new were put an angle
http://www.rodandcustommagazine.com/techarticles/0907rc_model_a_ladder_bars_hairpins/index.html

 

That is simply not true. With the original single ball joint, there is no beam axle twist by design, zero.
.
Now a forged front beam axle will certainly twist, even though it was never designed to do that. But just bear in mind that is now eighty year old steel.
If it is a cast iron beam axle and not forged steel beam axle, (they exist) you may be in trouble,
Drilling a forged steel beam axle is certainly not going to strengthen it.
Hydrogen embrittlement from chrome plating is also a well known problem for highly stressed steel parts.

So basically how far you wish to go to risk front beam axle failure is entirely up to you.

While a good quality forged I beam will certainly twist, a diff housing or large diameter front tube axle going to be all but totally rigid, and a great deal more thought needs to go into how you locate that big mother.

 

We've covered that, I'm just trying to clarify with warpspeed, his thoughts on splitting front wishbones or using hairpins up front....not on the rearend.

 

Show me in this picture where all the breaking or "metal fatigue" force is being applied?

 

To be fair, those were pretty dainty to begin with and I've seen it happen more than once. A cheap Speedway hairpin with no gusset in the middle will buckle with any real amount of torque combined with sticky tires.

 

And I don't think Warpspeed was all that concerned with the front end to begin with, more the longevity and construction of the rear set up.

 

Difficult to see, are those four bars or hairpins ?
If four bar, no sweat?
If hairpins, try removing one bolt where the hairpin joins onto the bat wing, and try putting that same bolt back in again with it jacked up like that. Then tell me nothing is under any stress.

 

Yes you are quite right, at the front you can get away with it with a skinny beam axle, but not with a solid tube axle at either end.

 

Don't know about that being so absolute either. I've got a buddy that drove a T bucket like that every day for close to 10 years and never an issue, although, It was a lot lighter and lower. I think there's some fudge room with things and besides, four bars are just plain ugly.

 

I have seen very expensive show rods with all the glittering metalflake and chrome, but with the most abominable non functional engineering imaginable.

To me that is ugly.

 

Very well put. I still think clunky four bars (on an open wheel car) are about as attractive as exposed cankles though.

 

I would also think very hard about using the mustang steering box with that front end. With the car sitting that high, and the pittman arm pointing upwards, bump steer is going to be a major concern.

 

Good eye, totally missed that.

 

That's a wishbone on a tube, with a tierod at the frame mount. Hamber B*** posted that photo when somebody told him that the setup wouldn't work on the Wade coupe that he did.

Try doing what you're talking about with the perch pin on an original early ford setup, or a tube axle and 4 link setup....or for that matter with a ball joint on a late model car?!!?

If you think any car with any suspension can drive down the road, go over bumps and not exert force on it's components, you're obviously mistaken.

Going over bumps with the orginal ball/yoke straight axle setup will push and pull straight back on the ball/yoke just the same as it would push straight back on the tie rod or heim joint in a spit wishbone setup.

As long as that frame mount end can articulate while one wheel comes up and the other stays flat, you don't make any changes to the original engineering that's even worth talking about. If the articulation maxes out, then you're adding torsional force to the bones...but good luck maxing out the movement in a tierod end.

This has been gone over and over on the HAMB, it's been done for over 50 years and it's still being done, because there is no problem with using hairpins or split wishbones mounted at the framerails.

And also to clarify, I do know this conversation started with talking about trad27's rear setup, but I'm not gonna sit here and listen to some guy say that splitting front wishbones and mounting them on the frame is the same thing as running straight ladder bars off the rear. I'm just calling the guy out, he's basically saying that 4 links on a front axle somehow magically eliminate any forces exerted while driving, while using spit wishbones dangerously increases the forces compared to original Henry engineering.

That's "simply not true"
-Steve