i am considering building new frame rails to replace my butchered originals.
Has anyone done it, i am thinking 6 x2 heavy wall tube with the steps and kickups in the right places like stock, and then reuse the front crossmember, body mounts etc etc.
This all to go under my 56 Panel.
Any thoughts guys?

John

 

Seems like a lot of work to me, I'd just find a better frame, but if you have the skills and equipment to do a safe job I say go for it. If you go through with it make sure you post a tech article with lots of pictures.

 

Not sure what's available in OZ but that seems like a lot of work for not much improvement over the OEM frame. If OEM availability is an issue and you do go forward with the 2x6 square tubing, I would not use a heavy walled tubing. One of the beauties of using tubing is that you gain a lot of strength without adding a lot of weight. A member of our truck club has an aftermarket tube frame and I was pleasantly surprised at how light it was due to the thinner walled tubing. I talked with Walton Fabrication here in SoCal some time ago about purchasing a set of frame rails...I belive they quoted me about $1,750 US. Whatever way you choose to go I would suggest that you have a good jig to lay out the frame and hold it square while you do your assembly. Good luck!

 

picking up an OEM frame is one of the issues, they are not so easy to find.
I would use tubing of the same gauge or slightly thinner than OEM and do it all on a suitable chassis table or jig.
I am a accomplished welder and would TIG the entire thing.
Seems to me, why not use the inherent strength of tubing rather than trying to repair my butchered frame and then still have to box it etc.
I am looking to build a torsionally stiff frame to support the planned IRS and IFS.
John

 

I say since you have the skills to do it, go for it. I would love it if you were to post a tech article with tons and tons of pics as you go along with it...

 

I didn't realize you were in Australia, it would help to have that information posted in you location. I see why finding a replacement might be a bit difficult.

With the skills and equipment you have I don't see it being that difficult for you to do it. Make sure to take a lot pictures and notes as you go and keep us informed.

 

Yeah, sorry about that, fixed now.......
I will post pics when i get that far, next couple weeks i hope if all goes to plan.
BUT, we ALL know how that can go LOL

John

 

I built a complete frame for my 59 CJ 5 out of 2x4 rectangular tubing. I did alot of measuring and built a jig using plywood and 2x4's to hold tubing at correct angles. Pretty much a duplicate of factory side rails. Made some new cross member but also reused some. Turned out real good but alot of work cutting the angles and welding. As long as you are a competant (sp?) welder you should be fine.

Good Luck,
Paul

 

FACTS:

2x3 x 1/8th wall rect. tube=3.9 lbs per foot. Can guess 2x6 x 1/8th wall will be near double the weight. In a 6 foot span of 2x3 x 1/8th wall rect. tube, at the center point (3ft) the moment of inertia is 468 lbs. In theory, double the height, the MOI should double as well. So 936 lbs per rail means you can hold 1872 lbs at the 3 foot mark of a 6 foot span. Factor in where the rear spring mount for the front, and the forward spring mount for the rear, it should be plenty heavy duty enough. 185.57" for the frame length, divided by 12 = 15.475 and at 3.9 lbs per foot = 60.3525 per rail times two for the both of them = 120.6205 lbs. Plus all of the crossmembers and such, will be plenty heavy for an F1. Should be no sag. One major drawback with the rect. tube, is no access to the inside when bolting parts on. Such as the shackles, which are riveted in stock form, so in order to reinstall everything, you'd likely be riveting everything in place after drilling the holes, as bolting on would be difficult, or you could run longer bolts all the way through.

END OF FACTS

 

Thanks for the input guys,

i dont think its an overly difficult undertaking, just time consuming and will also require attention to detail.
As i mentioned i am looking to build my frame to suit front and rear independent suspension, so i need a stiff frame to allow full suspension compliance.
Beaming (sag) wont be a problem i believe, however twist on a 34 wide frame may be more of a challenge.
Been reading a lot on the net but most of the info is more biased towards space frame chassis rather than simple old ladder frames, so more research is in order.......

John

 

I would probably use a 3/16" tube and cut/drill out 3 1/2" diameter holes @ 6" on center along the inside length of each frame rail. It provides a dramatic weight reduction without really sacrificing strength, and allows you to run wiring, etc... inside the frame rails. It also give a very cool, custom look to the frame rails. There's my $0.02.