cj2a frame build question's

[1946CJ2]

I am starting my build with a home built frame, for my 48 cj2a. I want to be able to stretch the body around 12" in the door area, and end up with around a 96" to 99" wheel base. I will use leaf springs and it will be SOA. I really like the look of RCKME52's build http://www.pirate4x4.com/forum/showt...t=family+build. I plan to use 2x4x 1/8" tube for the frame. The tubing will be stacked and then gusseted. Most everything for my build will be made by me, or cut from an old vehicle in my father in laws wrecking yard.

I have read several other posts, but I have some more questions before I start.

What hardness of steel tubing, do I use to build these frames?

Is the 1/8" steel tubing strong enough?

What thickness steel for the gussets and strapping?

Is this type of frame ok for daily driving?

Should I use 3/16" tube for the bumpers or is the 1/8" good?

Has anyone posted actual mesurements of there frame build?

I normally just start building with a trial and error type approach, however, I could save myself alot of work, by asking questions first.

Thanks,
Rodney

[dirtbikeboy54]

if it were me I would use 3/16 for both the frame and bumpers. if you havent done a lot of welding before I would look at driving something else as a daily driver. its just safer.

[1946CJ2]

My true daily driver is an '04 duramax, But I would like to be able to run the willys up and down the highway to my hunting area and slick rock.

[1946CJ2]

local steel price:

2x4x1/8" $3.00 per foot

2x3x3/16" $3.50 per foot

2x4x3/16" $4.50 per foot

[FordFascist]

I'm way too nice. Click my build link, you shall have your questions answered.

[DownNDirty]

It will depend on what you have in mind for the end use of the frame. My buggy frame is 2x3x3/16. All joints are mitered without fishplates at the moment. They will be getting fishplates once I pull the new motor out.

A CJ2a can be a different beast than most are use to. They are lighter and smaller and therefor don't really need as heavy a steel. When I do finally get around to my CJ2a build I was planning on either 2x3x1/8 or 1.5" HREW frame. And build it to be a DD. My '53 willys wagon has a chopped up stock wagoneer frame and if I were to build it again it would be all custom. There really is no reason to salvage any mounts off the stock frame.

If you plan on light wheeling then I think the 1/8" would be fine. mild wheeling make sure that there is a skid plate to cover it to keep dents off, or build with 3/16". On something that small and light I wouldn't mess with 1/4".

Robert

[Rooney77]

I'd consider what axles you plan on running as well. When building my frame I used 2x4x1/4" because of the rockwells and 44" swampers. But as light as the body is, remember that motor (the stocker) is really heavy at around 800lbs IIRC. So I wouldn't go less than 3/16" personally. But everyone has a different opinion.

[1946CJ2]

I think for the price difference the 2x4x3/16" would be the best. I will try and build it strong enough (with what I can afford / what my wife lets me spend) the first time. For axles I plan on wagoneer 44's front and rear. Tires to start at 35". powertrain is where I am still undecided. I could get a 4.3 chevy , but it would cost me more for the engine, tranny, adaptor, to the transfer case. I could do a buick v6, th400, and dana 20, for almost no cost to me. I just need to go pull the tranny / t-c out of the wagoneer chief. The buick v6 would come out of a passenger car (possible rebuild kit). The reason I am thinking an auto th400 is because of firewall room for the brake booster, clucth master, and pedal room. With streaching the frame a lttile the th400/20 should fit.

[Rooney77]

I was going to run a 4.3/th350/203 in mine. In fact it's all still sitting in my garage in the way. All of that will fit easily enough.

[1946CJ2]

would a 4.3/th350/np205 combo hang to low in a jeep?

[Rooney77]

The only issue I foresaw was the tcase but that's always the problem. If you're building your own frame you'll be doing your own motor mounts to so you can set that as high as you want.

[1946CJ2]

I was affraid the chevy transfer case would hang to low. This is why I was going to try and stay with a 20 t-case, out of a wagoneer chief. However, if I did use the chevy transfer case I could go with the 4.3/th400/205, without an adaptor.

[FordFascist]

Originally Posted by 1946CJ2

I think for the price difference the 2x4x3/16" would be the best. I will try and build it strong enough (with what I can afford / what my wife lets me spend) the first time. For axles I plan on wagoneer 44's front and rear. Tires to start at 35".

You understand that both the torsional rigidity and the load-carrying capacity increase inversely to the wall thickness don't you? What that means to the lay person is the nominal strength increase of going from .120" wall to .188" wall on a 2 x 4" frame is in the single digits if you include the added weight of the tubing itself. Whoever suggested .250 wall clearly lacks understanding on a frame's strength, I'll say it in caps so it makes more sense: DOUBLING WALL THICKNESS DOES NOT DOUBLE STRENGTH. You are just adding extra weight to your rig, with no tangible benefit.

You gain resistance to load deflection (frame sag) with the taller tubing, and resistance to twisting with increased tubing width.

Fish plates along the side are not really needed, although I added them just because they looked trick. The load on the frame tubes is mainly tension on the bottom of the tube and compression on the top, and vice-versa depending on which part of the bend you are loading. What this means is you need the gussets on the tension side of each bend. Also, if you bulk-head each bend, you gain something in the range of 20% joint strength as it resists the tendency of the tube to want to crush with a bending load on it.

[Rooney77]

As being the one that suggested the 1/4" tubing I feel I should respond. And just to be sure I'm not assumed an idiot, I am currently working on my masters in mechanical engineering. What you say is true but the thicker wall does add other benefits. For instance, on butt welds there is more wall that can be chamfered to allow for more welding surface area (my welds suck so I took this into consideration), and from my experience will warp less from heat. The same holds true with any mounts that go through the frame, thicker walls will tend to buckle less if the mount isn't sleeved. These were all concerns of mine which is why I chose the 1/4 wall tubing. Yes I know and understand that it's the exterior dimensions (essentially) that increase the strength, at least more so than the wall thickness. I was thinking as much about my ability to work with the material as much as the end result. These are small issues to most but for me they outweighed the weight gain with going to 1/4" wall. But I'm also running rocks so nitpicking weight isn't a real concern. I did spend many hours researching and crunching numbers and thats what I came up with. I didn't necessarily choose the 1/4" for the additional strength. I was simply offering my experience. I never suggested that doubling the wall thickness doubles the strength. And above all else, when it came time to shop for steel I got the 1/4" cheaper. And besides, I may be an asshat but I'm not an idiot.

[1946CJ2]

I just got done reading your link fordfascist. Thank you for the info. This is why I am asking questions. Can you explain, how you bulk-head the joints? I am not familar with that term. what strentgh steel did you use on your frame?

[FordFascist]

Bulk-heading, as in capping every tube where there is a bend.

Like this:





Then this is what I did t reinforce the frame at critical bends, 3/16" plate where the frame widens at the rear shackles. It's probably overkill but it wasn't too much weight:




As for Rooney, I wasn't calling you dumb, but there are far more effective ways at building a frame than just throwing thicker gauge metal at it. I built the bumpers out of .188" wall so they wouldn't dent when contacting rocks, but as for the other stuff I didn't need to go that thick.

[Rooney77]

Nah, I knew you weren't calling me out or anything. I was just explaining my reasoning for going with the thicker stuff. I know that in 99% of the situations that it's not the best choice, including mine. I just felt more comfortable using it. But I'm like that.

[1946CJ2]

Thank you all for the info, and thank you fordfascist for posting the pics.

As far as the steel grade, I believe I am going to use "A500 grade B 2x4". If anyone knows of a problem with this grade, please let me know.

SEMPER FI

[Haggar]

A500B is fine. Holds up well, in my experience with dent resistance. Its cold worked.

For a flattie, 2x3 or 2x4 with 1/8th wall is just fine. I'm using a combo of 2x3 and 2x4 1/8th wall for my CJ6. Was all 2x3 for my CJ3b.

Stock frames are 1/8th thick, 2x3 on the ends, 2x4 in the center, but open C- channel. Modern 2x3 box tube is better than 50 year old 2x4 C-channel.

The bumper is up to you, if you bash yours alot, go heavier. But there's really no need for more than 1/8th wall on a frame, for most poeple. Especially a flattie like that.

[rckme52]

Originally Posted by 1946CJ2

I am starting my build with a home built frame, for my 48 cj2a. I want to be able to stretch the body around 12" in the door area, and end up with around a 96" to 99" wheel base. I will use leaf springs and it will be SOA. I really like the look of RCKME52's build http://www.pirate4x4.com/forum/showt...t=family+build. I plan to use 2x4x 1/8" tube for the frame. The tubing will be stacked and then gusseted. Most everything for my build will be made by me, or cut from an old vehicle in my father in laws wrecking yard.

I have read several other posts, but I have some more questions before I start.

What hardness of steel tubing, do I use to build these frames?

Is the 1/8" steel tubing strong enough?

What thickness steel for the gussets and strapping?

Is this type of frame ok for daily driving?

Should I use 3/16" tube for the bumpers or is the 1/8" good?

Has anyone posted actual mesurements of there frame build?

I normally just start building with a trial and error type approach, however, I could save myself alot of work, by asking questions first.

Thanks,
Rodney

Thanks for the kind words. since I have been wheeling the crap out of the flatty the only thing that i would change or add is stretching the rear of the tub about 6 inches as well. pushing the wheel base out to 104-106 with 40" tires would be my preference. but damn i am really happy with the my flatty its pretty much point and shoot. I would also not use the 44044s in the rear, i keep bending them every run. I would link it, or have a custom set made from alcan or donahoe. I love the 4.3 its perfect for me and how i drive, nice and quite. If you drive alot, carry a big load I would recommend a 5.3.

I just brought my two youngsters into the con for the first time last weekend. full load, coffin cooler on the tailgate and full roof rack packed. and still went right up the soup bowl in10 seconds

good luck with your build. call me if you have any questions, i would be happy to answer them. 650-868-5233

Ron

[1946CJ2]

RCKME52, I sent you a pm.

Thanks

[1946CJ2]

well, I spoke to Ron and he gave me alot of good info (Thank you, Ron), and I have been searching and reading for a few weeks now.

I picked up a matching set of scout d44 axles (for cheap). I have them gound down and ready for SOA mount, they will have chevy flat top knuckles, discs, and ford 5 on 5.5 hubs/rotors and for the caster, I will cut and turn after all weight is installed on the stretched cj2a.

Current build plan 4.3/th350/np205/scout II d44/chevy or dakota springs

Due to the spring mount width of the scout II axle (with 2.5" wide springs) and the width of clocking the np205 flat, I was thinking of making my frame wider. The id would be 29.5" with a 31.5" center. I do not know how this would look with the front frame rails a little wider than the grill.

Does anyone have pictures of a flattie with the wider frame? PLEASE POST THEM

I see other benifits with the wider frame also with more room for the plumbing and steering, I just do not know how it will look.

Thank You,
Rodney

[SVARAS]

Originally Posted by 1946CJ2

Does anyone have pictures of a flattie with the wider frame? PLEASE POST THEM

This is 34" center to center of the frame rails.
I went with that measure, beacause I´m using Wagoneer 44´s (34" is the distance from center to center on the spring pads). Also it gave me the clearence I need to run the stock 5.3 headers.
For me, it looks ok...
BTW, I used 2"x4"x.120 for the frame.

[rckme52]

Originally Posted by 1946CJ2

well, I spoke to Ron and he gave me alot of good info (Thank you, Ron), and I have been searching and reading for a few weeks now.

I picked up a matching set of scout d44 axles (for cheap). I have them gound down and ready for SOA mount, they will have chevy flat top knuckles, discs, and ford 5 on 5.5 hubs/rotors and for the caster, I will cut and turn after all weight is installed on the stretched cj2a.

Current build plan 4.3/th350/np205/scout II d44/chevy or dakota springs

Due to the spring mount width of the scout II axle (with 2.5" wide springs) and the width of clocking the np205 flat, I was thinking of making my frame wider. The id would be 29.5" with a 31.5" center. I do not know how this would look with the front frame rails a little wider than the grill.

Does anyone have pictures of a flattie with the wider frame? PLEASE POST THEM

I see other benifits with the wider frame also with more room for the plumbing and steering, I just do not know how it will look.

Thank You,
Rodney

right on Rodney, Come on over anytime and takes some measurements of my rig. I am heading to fordyce and moon rocks in a couple weeks. Hit me up you want to go wheelin or chit chatttnnn.

650-868-5233
Ron, (rckme52)

[LAME]

Originally Posted by 1946CJ2

well, I spoke to Ron and he gave me alot of good info (Thank you, Ron), and I have been searching and reading for a few weeks now.

I picked up a matching set of scout d44 axles (for cheap). I have them gound down and ready for SOA mount, they will have chevy flat top knuckles, discs, and ford 5 on 5.5 hubs/rotors and for the caster, I will cut and turn after all weight is installed on the stretched cj2a.

Current build plan 4.3/th350/np205/scout II d44/chevy or dakota springs

Due to the spring mount width of the scout II axle (with 2.5" wide springs) and the width of clocking the np205 flat, I was thinking of making my frame wider. The id would be 29.5" with a 31.5" center. I do not know how this would look with the front frame rails a little wider than the grill.

Does anyone have pictures of a flattie with the wider frame? PLEASE POST THEM

I see other benifits with the wider frame also with more room for the plumbing and steering, I just do not know how it will look.

Thank You,
Rodney

2X4X.120 has held up in my rig for years. First with 4.3, now with a TPI V8. Fishplate all joints. I didn't and broke the frame at a couple joints

My frame is stock width all the way back, and a clocked D300 barely fits....so I would make the frame wider then stock with a bigass 205.