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GrantH
07-13-2006, 08:04 AM
Im looking at building a frame for my 1972 f100 instead of finding a 50's car right now. I have a level garage floor, so most likely a table will not be built. I am just wondering what I should incorperate into the frame for strength. Im looking at running 3x3 rails off of a full size chevy front clip. (88-98 1500) My plan is to weld all seams at the connection point where the rails meet that clip, then box it in entirely, and weld where the box ends and the rails begin. I guess I just explained the standard procedure haha. How would you guys (ideally) integrate the tranny member into it all? Would you ben up some round tubing and make a cool crosmember out that to hold it up or just run g a simple crossmember. As far as the rear is concerned, just notching the back but leaving the rails up at the notch, and not dropping them back down.This way I can hold my fuel cell up off the ground when i lay it out. Im contemplating running a strut bag out back and regular bags up front.


Really my concern is joining everything together. What type of welds would u run? I have a mig welder strong enough for 1/4 inch wall, but do you "V" the edges and fill in the V with weld or whats the best way to go about it. I may do the most rearward part like the guy here with the 37 chevy i believe, rounded off in the back.

KMAC
07-14-2006, 04:16 AM
Grant
It sounds like you have got it laid out well.As to the welds if you can weld up to 1/4 inch you should be okay. If you are not sure of your welding try this. Weld up a practice piece and then cut it apart thru the weld with a hacksaw and look at your penetration. Another trick is to look at the weld after you have cut it and put a couple of drops of battery acid on the weld and then wipe it off and the weld separation and penetration will become evident . Of course dont get any of that acid on your self but you already know that. It will let you know when it touchs you.
KMAC
Kenny

GrantH
07-14-2006, 05:12 AM
ill stick to the hacksaw test LOL. my only deal is the front end width, hub to hub. I havent been able to find a width, and the guys on the fullsize forums arent exactly the most helpful when I tell them my plan.

anders nørgaard
07-14-2006, 06:22 AM
Hi Grant,

Did a Google. Looks like the track is 63.6". Then you'll need to know the rim center offset to find the distance from hub to hub.

http://www.nctd.com/printversion-review.cfm?Vehicle=1997_Chevrolet_C1500&ReviewID=294

Jim Stabe
07-14-2006, 08:22 AM
Grant

At the point where you join the 2 frame sections together, try to avoid perpendicular weld seams. Cut the pieces at a 45* angle so you spread the weld stress area over a longer length of the frame. I can't imagine that the frame is 1/4" material but if welding something that thick I would definitely bevel the egdes to get good penetration especially if you can't get to the back side to weld. You also might consider adding a reinforcing plate that extends at least 6" on each side of the weld seam. Make sure everything is clean so you don't get junk included in the weld.

Good luck

Jim

GrantH
07-14-2006, 08:30 AM
thank you anders. I hope I can just keep it how it comes off of the chevy, that would be awesome. Truck seems about the same size, just gotta get mine figured out now.

As far as cutting them at a 45, the only rails that would be cut is the notch to go upwards. After finding whatever angle I need, I guess it would be best to cut both pieces at a certain measure to get than angle instead of one piece flat cut vertically and one at a 45? am i right? instead of 45, have two 22.5 angles?

rsanter
07-14-2006, 08:56 AM
the idea of cutting at an angle is for the purpose of spreading the load over a longer area of weld. that way any bad spots in the weld would be a lower percent of the weld area and reduce the strenth less. the idea of a added plate (fish plate) will also work to spread the load over a larger area and if installed on the inside of the frame will not effect the looks. another thing people will often do is add a sleve inside the hollow area of the frame and then bevel the frame such that you will get penetration through the frame and into the sleve to add some strenth.
when welding you will want to be sure that you are not welding cold metal. if you do this work in the summer then you have no problem. if it will be winter before you get to this, you will want to do the welding on a heated shop with the metal normalized to shop tempature. either way you may want to wrap the weld are after welding to slow (better control) the rate of cooling so as not to induce any additional stress in the weld area.

bob

rookie
07-14-2006, 08:59 AM
Hi Grant. Yes, make you cuts 22.5, they will line up much nicer without as much of a 'step'. Bevel the hell out of it, there's nothing wrong with helping the torch with penetration. Making a nice clean plate to cover both sides of the joint wont look that bad either. Tack well, brace well, clamps and some square tubing will help keep everything in line as you weld so the weld wont pull it out of line. Move around instead of welding in one continuous bead. Level everything from front to rear and from side to side before you weld it up.

Happy fabbing, Phil

GrantH
07-14-2006, 10:59 AM
I may use the sleeve idea, that sounds like a good one. Now to get the truck back running, buy the front clip, gas, and rails.......geez.

Bambi
07-14-2006, 04:49 PM
I'll put in my two cents worth. Not to burst any bubbles, but its a truck, even a custom one. I am gonna say Budget. If you got deep pockets and a lots of time go for it, only its a lot of over kill. Sounds like your gonna build a tank.
I would go and find another 72 if the original frame is that bad. For that matter vehicles are plentiful, go and pick up a late model Ford complete and pop your body on it. You'll get a good drive train with quality parts, not a mix master nightmare. There are plenty of aftermarket parts available for lowering, handling etc. You can tub out the rear if you want. Boxing a frame was done with T's and Duece frames cuz they were so thin walled. Chevy and Ford late model truck frames are all heavy duty, no need to box. Only some places need boxing particularly if the truck is 4wd and your into rock climbing.
I assume your plan is to lower the vehicle and put it in the weeds so to speak, with nice wheels, paint etc. You want a nice comfortable ride and somethin that handles. Goin with the late model stuff and putting your money where it will do the most good will bring you closer to your dream, better and faster and cheaper.
Good Luck

Bambi

GrantH
07-15-2006, 06:20 AM
Not to burst any bubbles, but its a truck, even a custom one. I am gonna say Budget. If you got deep pockets and a lots of time go for it, only its a lot of over kill. Sounds like your gonna build a tank.
I would go and find another 72 if the original frame is that bad. For that matter vehicles are plentiful, go and pick up a late model Ford complete and pop your body on it. You'll get a good drive train with quality parts, not a mix master nightmare. There are plenty of aftermarket parts available for lowering, handling etc. You can tub out the rear if you want. Boxing a frame was done with T's and Duece frames cuz they were so thin walled. Chevy and Ford late model truck frames are all heavy duty, no need to box. Only some places need boxing particularly if the truck is 4wd and your into rock climbing.
I assume your plan is to lower the vehicle and put it in the weeds so to speak, with nice wheels, paint etc. You want a nice comfortable ride and somethin that handles. Goin with the late model stuff and putting your money where it will do the most good will bring you closer to your dream, better and faster and cheaper.
Good Luck

Bambi


no offense, but what your saying is worse than what i would like to do, and not what I want. People have built 2x3 and 3x3 frames for trucks for quite some time now. As far as it "being a truck" whats wrong with that...."even a custom one". My idea of a bad ass ride is different than yours im guessing. Im building a new frame to get AWAY from ford parts, specifically the twin i-beam suspension. Why would I go and throw it on a later model ranger frame.......they are I BEAM as well. I dont need something that handles like its on rails, just something that doesnt float like its on water, but still a soft ride, and not bouncing up and down (think cadillac ride). Air ride and a 4 link out back with a well thought out front air ride setup will be MORE than enough for that ride.

Most the time, the boxing is done because we (what some would call) "abuse" our trucks frame. Dragging and hitting switches and stuff, a C-channel frame isnt ideal. As far as having "quality parts" im guessing you mean drivetrain. What makes you think im not going fuel injected 302 out of a later model mustang with a tranny to match, or even a 351 out of an f150 with the tranny to match. Nobody said anything about motors or anything, but more so about the frame itself. I will keep it at 3x3. The stock frame is 2x6 for some reason...

Tin Head
07-15-2006, 07:19 AM
Grant,

I have a 73 F100 that has been in my family since it was new. It has a tired 390/C6 now. I have been looking at the late model trucks and SUV's as they all have newer A-arm coil suspension up front along with a very well engineered 4.6l SOHV engine. You can even find the all aluminum 4.6l DOHC's around. I'm thinking, when it comes time to freshen up the old daily driver, that clipping in one of those is probably in the cards. Been looking at the rear IRS from the SUV's as well. I intend to keep it all Ford and it would be great if it all came from the same donor. And there ain't nothing wrong with trucks, I got three of em, all old.

Bob

Boogiemanz1
07-15-2006, 08:57 AM
Oh and Grant, my Cadillac has 4 wheel independant and bags....factory.........john

GrantH
07-15-2006, 12:37 PM
for the IRS in the f100 tin head, think lincoln LS. cheap at junkyards as far as the rear end is concerned. im most likely clipping it with a chevy, fords are the worlds worst to bag, no matter what frame is under it.