No other like it.

[cornfield customs]

the rear suspension makes me nervous as well. for one the tractor third member links are not really that strong. the heim style ends are usually cast. also the way you have the ends set up the ones attached to the frame will bind as the the suspension travels. also that thing will be a pain to drive with that long wheel base. i think you you will have some major flex or breakage issue with the frame being water pipe. also the front end will cause issues with bump steer, as stated by others.

 

[8literbeater]

I wouldn't be using any type of sprinkler pipe in any part of your build. Keep in mind that stuff was never intended to carry a load other than it's own weight. And if you can haul a 21' piece of that 6 1/2 inch pipe on your shoulder it tells me that it isn't very thick and I see in one photo that it has a seam. I'm not trying to knock your work and I really like the looks of the large pipe like that as the frame, but I just don't think that it's safe.

38fordtruck has a good point about the hiem joints on the rear suspension. The hiem joints are not built to control movement like ones you have bolted to the frame on the rear. You might want to consider repositioning them so the bolt itself is horizontal.

Someone else might have some input on this. I really dig the innovative thinking...just want to make sure it's safe as well.

-Troy

I appreciate the concern, and I know it's hard to tell when someone is trying to kill themselves without them knowing it. I will try to gain some trust without stepping on any toes here. I know that there are some very fine builders here that far exceed my abilities, experience, or goals.

I am usually very thorough with my projects, and I've done my homework on this one. The pipe, I want to clarify, is not irrigation sprinkler pipe. It is commercial building fire sprinkler pipe manufactured to meet or exceed ASTM/ASME standards and certification. It is 6.625" schedule 10 pipe, which is .134 wall. It comes in 24 foot lengths (darn my memory).

It is tested for crack resistance, with vibration, for bending resistance, and of course all of this is tested at 300psi. It must also withstand 700 psi without cracking, but we all know that hydrostatic pressure has little bearing on structural integrity.
On page 36 of the document linked below, you can see the test standards that this pipe is required to meet as a minimum. The bending moment is 5185 pounds per foot when supported on one end. It is 5185 pounds force when applied to the center of a joint that is supported on two ends, 4 feet apart.
My frame is around 10 feet between structural supports, with no joints. The way I figure it, the minimum strength requirement is around 1500 pounds in the center, and the weight is not mounted in a single point in the center anyway.
As a side note, it shows everything as being tested at 175 psi, then on page 22 there's a modification that says it is "now to be evaluated at 300 psi".

http://www.fmglobal.com/assets/pdf/fmapprovals/1630.pdf

http://www.engineeringtoolbox.com/steel-pipes-dimensions-d_43.html

As far as the rear suspension travel, seriously, I can unbolt one end and move it up and down to see that it travels PLENTY far, although I know it looks as though it wouldn't. And they are category 1 hitch top links, of which there are normally one on a hitch, this has two. They don't support any weight of the vehicle, only axle rotation, and the heims take 3/4 inch bolts. If tractor links weren't built for heavy use...

I don't mean to be a pain with all the numbers and junk, but I really think it's going to be every bit as strong, and stronger than any 2x3 or 2x4 rectangular tubing, which is also welded.

Also, I bring this discussion to see what I can learn. I'm in school working on an engineering degree, and while I am not that far into it, I enjoy working this stuff out with what I know, and can learn from other people.

 

[RAT IHC]

Sounds like you've done your homework. I don't know enough about the standards for pipe to give input on it, maybe someone else does. A lot of guys here have a ton more experience than I do and everyone does things differently.

Three things that I would say do more homework on are:

1. Possible bumpsteer

2. The rear heims that are bolted to the frame...they should be positioned like the ones bolted to the diff.

3. Looking at the rear where the tab are welded to the pipe might be a stress point...may want to add some extra metal there.

Keep us posted on your progress!

-Troy

 

[sgtpontiac]

It sounds like you've covered the bases....

If you are confident in the structual integrity of the frame then who am I to say otherwise.... it is really outside the box thinking but then again...that is how things are developed and tested.... good luck with build and I'm sure you'll keep us informed as to how this pans out..... I think you've thought it out well and are moving ahead... just make sure you consider all the safety related possibilities..... but ultimately, driving and testing will let you know in a hurry if you need to rethink anything.... nice job...

 

[Old Iron]

I'm not sure on the year. I thought it was '84, then I found something that pointed to '73. it has a crapload of emissions garbage on it, and HEI, so I'm leaning more toward the 80's. It has the integrated intake manifold, the exhaust manifold has had a crack welded up, and I might end up finding a replacement myself. The carb, however, I am not planning on using!

I think I'll throw some info up on another thread somewhere for my '59. Is there a section for builds that are not low to the ground?

The first one of those engines I saw was in my Uncles pickup in around 84, 85. The crazy thing ran pretty good

Jim

 

[fetalinjury]

that frame

If your right and that frame is beefcake like you say... Bravo to you ... Innovator.. is the only word coming to mind. keep it up .

 

[Bonehead]

Okay, I know something about pipe, and something about tractor links, and welding, and 4 links. So here is my take on this project. The tractor links are plenty strong, I have them on my rock crawler, and they have worked under very extreme conditions for years with out failure, They have however worn out to the point that they are loose, and rattle. They would not be my 1st choice for a street driven vehicle, but they will probably work okay. I would check on them often, and replace them often as well. I would turn the front two mounts, simply because, in the current configuration, they will wear out even faster.

On to the poo pipe, as it is called in the welding of real automotive tube work. Three kinds of tubing is widely accepted in the fabrication world, for cage and frame work. Chromoly, DOM, and HREW. The danger of the pipe you are using, is that it can rip at critical union points next to a weld. On the otherhand, the tubing is of large diameter and that helps. Basically what I am saying is you are welding parts on to 1/8 inch thick, (or less) sheet metal rolled into a curve. Yes, the pipe is made to hold pressure, or PSI, but not structural strength. The frame itself is much like a unibody frame and will probably hold up. But anyplace you are connecting suspension componets to may need to be beefed up.

I really like the style, and look of the truck, and the ideas are great. As I said in my first comment, the tierod is my biggest concern. I can see it shearing off tierod ends, instead of just changing the tow-in. Mainly because the suspension will cycle thousands of times, as it goes down the road. Not to the maxium, but a little all the time. The tie rod will fight the suspension, and the weaker one will loose.

With the thought you have already put into this, I am sure you can solve these minor things, and still put the truck on the road. I am looking forward to seeing what you come up with.

 

[8literbeater]

Thanks for the encouragement guys.

Bonehead, I completely agree with you. Poo pipe? That's awesome.
The only thing with the tie rod ends, as far as I know, the standard Chevy tie rod end will cycle 20 degrees each direction, and this reaches exactly 20 degrees right as the frame touches the ground. That's if the tires don't compress at all. I'll double check it and put in travel limiters if needed. I could also use drag link ends, since they're more intended for movement this direction. Chevy drag link ends travel 30 degrees each way, but I'd have to have the tapers reamed out to fit. I'll see how it goes, I've built some steering systems in the past. By any chance, did you get a peek at my project when you were at Earthman's house?

Old Iron, I pulled that exhaust manifold and carburetor yesterday. It's a Rochester Varijet I think. Let me know if you can use it, I haven't worked in about 3 weeks and, well you know. So the three of the bolts had been already broken off in the exhaust, and a crack has been welded, and recracked. Guess what else I found?





It turned out to be just an empty shell. Still, it's a reminder to wear gloves.

 

[Tim...Ok]

just the sight of that scorpion gives me the heebie jeebies..been stung by them more times than I care to remember..seemed like they were everywhere at my parents place when I was a kid..

Really like the frame work you've done..I was going to do similiar rear springs on mine but ran out of room back there pretty quick

Tim

 

[Sam_Fear]

Now, while independent suspension, doesn't really mix with solid tie rods, or rat rods for that matter. I still have hope.

What do you guys think?

I don't think it will work well. Did some quick math.

At 20" radius and a 1.5" arc off center (which I figure is normal road), one hub will move inward about 1/16". Not much, but that means your toe measured at the front/rear of the tires will change outward approx. 1/2". At 3" arc, that increases somewhere around 1/4" at one tie rod end and 2" out at the tires edges. This is assuming that both tires are oscillating at the same time and using a 32" dia. tire. And I coulda screwed up the math.

My guess is, even when you hit the brakes real hard, it's gonna want to veer hard to the side.

 

[Old Iron]

Yep you folks in Arizona have that to contend with.
Isn't the green ones the worst to get stung by ?
If you want, PM me and we'll see if we can make a deal on the carb.
I didn't know the intake was part of the head though and that the exhaust dumped out like that. Wow

Jim

 

[BigIrish]

Thanks for the encouragement guys.

Bonehead, I completely agree with you. ....the standard Chevy tie rod end will cycle 20 degrees each direction, and this reaches exactly 20 degrees right as the frame touches the ground. That's if the tires don't compress at all. I'll double check it and put in travel limiters if needed....
.

I think his point on this is not the degrees, but the harshness and frequency of the impacts to those rod ends. When you hit a bump, that suspension pops up in a fraction of a second, and very hard. Way harder than you could ever manage to inflict on the rod ends by turning the wheel. This is going to be happening all the time as you go down the road.

I think the best solution is to drop in a rack & pinion steering rack in place of that tie rod, since they have joints to allow for independant susp movement. If you can find a narrow rack from a small car, it would work pretty well.

 

[Timeless softshoe]

man thats one odd rod, [P still watching ,

 

[Dr Crankenstein]

Bonehead makes a good point. When you weld things like your torsion adjusters to the pipe, you should put a pad under it. It distributes the stress over a much larger area, and eliminates tearing the wall of the pipe.

Weld the pad on the pipe, and the bracket to the pad.

I agree with the guys about the heim end. Flip it to vertical so it pivots on the correct axis.

I also agree with the guys about the bumpsteer issue. I don't see how you can avoid it without eliminating the solid tie-rod.

I don't know if this is reasonable, but I thought I'd share my idea. Basically two Watts links tied together. Keep the tie-rods the same length as the A-arms, and allow them to pivot independently.

Another crude drawing,

 

[T DRIVER]

O K

Looks kinda heavy But your getting there. [P

 

[Bonehead]

Hey, Doc, at first I thought you had it figured out. Then I started cycling the suspension on one side, in my mind, ( You probably didn't know I had suspension up there), and I am thinking it will bump steer like crazy. I could be wrong. The answer might be similar to a Y shape tie rod of a 78 Ford Bronco. It cross steers, but there should an answer to that as well.

 

[rainman]

I don't think so, not if the tie rods are the same length as the control arms!

 

[8literbeater]

Doc, I actually did use pads just like that where the springs attach under the cab. Of course the springs are bolted and not welded, but that's a good idea for the welded tabs. I honestly have not been 100% certain that they would not come loose, but I have really good vehicle inspection habits.
Since it would be a pain to cut them off, clean it up, and get them back in the proper position, is there a good type of gusset that would prevent cracking? I was planning on maybe having to reinforce it with gussets.

Anyway, I actually really like the steering idea and picture you have there. I honestly might end up using your idea. Of course, I'm gonna get it where I can at least test drive it first. I thought originally that I would use rack and pinion, but I just couldn't make it look right in my head.

I guess I'm gonna throw another build thread on here for my 59 Chevy. I'm sure the steering setup on it will get some comments. Keep an eye open for it!

 

[Dr Crankenstein]

It might be a pain, but I would still cut those tabs off, and install a pad. Duplicating their position isn't difficult. Make gussets to fit the tab where it sits now. Mark the frame from the center of the tab in both directions. Cut the tab off. Fit the pad where you want it, and tack it on. Transfer the lines from the pipe to the pad. Position the tab according to the new marks on the pad, add the gussets, and fry it up.

Bonehead, I have pictures in my mind, too. Until we start to hear voices, I think we'll be OK.

I believe bumpsteer exists in every design, the question is, how much? The voice (I mean picture) in my mind said make the tie-rod the same length as the A-arm, and parallel to it. That should reduce the effect, no? Clearly you have a different movie playing in your head, can you share it with us? I'd rather learn something than let my brain consume itself with improbable ideas. [S

 

[BigIrish]

I believe bumpsteer exists in every design, the question is, how much? The voice (I mean picture) in my mind said make the tie-rod the same length as the A-arm, and parallel to it. That should reduce the effect, no? [S

Yes, if the tie rod is the same length as the control arm, and the inner pivot point of both is on the same plane vertically, then they will rotate in the same arch and in theory there will be no bumpster (at least when the wheels are straight).

I think you nailed it Dr. C! [cl