boxing your frame

[bigmac73]

when and how would box in your frame??

[Domer]

What's the question? When would you? When you are trying to increase handling to make it more rigid. How? Cut plates and weld them in. I think there is a company that makes pre cut plates already.

[bigmac73]

just curious if I should, if was going to add a big cubed SBC with lots of torque

[Domer]

Then I'd say yes. I took my bare frame in and had it straightened, then boxed and added a center support to make it more rigid.

[BR3W CITY]

I was about to say "when its warm, and in the garage"...but that clearly isn't helping.

How much power are you actually planning on making though? "big cube" small block would lead me to think in the mid 400ci, but that could be anywhere from 350hp to north of 1000.

Since your not installing a motor that itself weighs more, boxing your frame might not have the effect you really want. All of the additional metal will add weight to the vehicle, effectively counteracting some of the new power you plan to add. The strength gains also may not be in the places you'd hope.

Boxing the frame for a heavy motor (huge bbc, diesel, something else), or in something that will be heavily loaded can work. Boxing can also help resist the forces trying to "fold" the frame, for example from being jumped or from doing a wheelie and coming down hard....but it isn't as effective in terms of resisting frame twist.

To combat that, its all about finding a way brace/connect parts of the frame so that the force being applied to it can be transferred in a manageable way, or counteracted by another force. If you were to take most of the rungs out of a ladder, you could pick up on side and watch the whole thing twist...the truck works the same way.

Tubular cross bracing, replacing or bracing crossmembers, rollcages all have this effect. I'd spend the time and the effort on a tube back half for example, which is not only lighter, but stiffer (but does not have the same load carrying capacity). You won't see a ton of fully boxed frames going down the strip.

[Gary V]

Lot's of work if you do it right... makes adding crossmembers, motor mounts etc. easier. When working with stressed material that is 40 or 50 years old, you will discover that there are cracks that develop over time. The cracks originate from (link) stress raisers Eliminate the stress raisers and box the frame and it will be stronger and more ridged... less apt to twist if you add additional crossmembers.

So enough of the technical stuff! Get yourself some cheap paneling at home depot, don't use cardboard. Clamp a strip ( using many clamps) to the frame rail, mark it out with a Sharpie. Cut it out with a scroll saw and transfer to a piece of 1/8" 1018 strip... that's all you need!

The paneling has similar bend characteristics to bending the 1018... so if you see any gaps when you clamp it up. Grind the frame until you get near zero gap. That way you will get minimal distortion when you weld it up slowly... tack it along the length and then fill in the welds 1" at a time. If you can put your bare hand on it without getting burnt... weld some more.

Link to some pics

Frame box

[Domer]

Look at my build, the last page I just uploaded some of the bracing I built. I'm building a road race truck with 650hp blown SBC and T56.

[4 Wheelin Fudpucker]

Boxing was done to 4 banger old 20s and 30s frames to make them stiff enough to handle V-8s.
Most modern truck frames are rated for both 6 and 8 cylinder engines.
Chain and a turn buckle on the left side of the motor would be a faster, cheaper and do the trick mod for extra HP.

In all my years Ive planted a lot of V-8s in rigs that didnt come with them. ONLY my 1930 Ford coupe got boxed.

[dirtyjim]

I boxed the 72 I had as a teenager. I wouldn't waste my time boxing one now but I would add a minimum of a 6pt cage and some triangulation from trailing arm crossmember back to around the rear axle centerline similar to the way the hotchkins truck is done.
you'll stiffen the chassis much more this way.
if I was going boxed I would sell the original frame and start over with 2x6" under the cab and 2x4" for the front and rear followed by a cage

[slotard]

That's a good point, in order to box everything up you need to strip it to a bare frame. At that point, if you have the tools it might not be too much extra work to do a custom frame then, and you get to work with new material rather than a frame that's had 40+ years to corrode/crack/etc and has had who knows what done to it.

[Gary V]

With respect to the OP and not wanting to highjack the thread. The boxing will strengthen the frame and you don't need to strip it bare to accomplish that. Everytime I see one of these threads it gets convoluted with finite element analysis, theoretical engineering and arguments. As far as building the frame ground up... yes it's easier. Then you need to deal with your states DMV if you ever entertain the idea of selling...... because you've eliminated the frame serial number and that can get ugly.

[70blackfish]

some jeeps from the early to mid 70's or more had the front 5 feet of the frame boxed from the factory..rear was c channel....

[SierraMtns]

Originally Posted by Domer

What's the question? When would you? When you are trying to increase handling to make it more rigid. How? Cut plates and weld them in. I think there is a company that makes pre cut plates already.

Do you have a link to the company that makes these plates?

[drfloyd]

Here's mine I'm boxing now. Just have a couple of small sections to finish and welding up the bottom. I added the tunneled X Brace. It has an integrated trans mount. I just did it because I wanted to. I entertained the idea of a new rolling chassis but I wanted to use mine and have the frame number. Johnny Law Motors sells the pieces as well as No Limit Engineering. I think NL is in sections so it's easier to handle. JL looked like it was the entire side.

I enjoyed doing it. The welding gets monotonous.

[drfloyd]

I also welded up all of the holes in the frame. Here's another attempt at the pic that was sideways.

[drfloyd]

BTW, I just bought 3/16" x 6" metal and made my plates.

[SierraMtns]

Originally Posted by drfloyd

Here's mine I'm boxing now. Just have a couple of small sections to finish and welding up the bottom. I added the tunneled X Brace. It has an integrated trans mount. I just did it because I wanted to. I entertained the idea of a new rolling chassis but I wanted to use mine and have the frame number. Johnny Law Motors sells the pieces as well as No Limit Engineering. I think NL is in sections so it's easier to handle. JL looked like it was the entire side.

I enjoyed doing it. The welding gets monotonous.

Thanks man for the pictures. I just sent Rob a message asking if they made any X cross members. What did it cost?

Did you run full welds when boxing the frame? Did you use 1/8" or 3/8" to plate the frame? I measured my frame last night and it looks like it is 1/8" thick.

[drfloyd]

This X Brace is from No Limit. I don't know if it will work on a trailing arm system, I have Rob's 4 link Fat Bar. I'm thinking is was around 600 with the trans mount.

I used 3/16" x 6" flat stock. I spotted it in as I fitted it and then welded it in all the way. I wanted a smooth finish when I am done.

[SierraMtns]

Originally Posted by drfloyd

Here's mine I'm boxing now. Just have a couple of small sections to finish and welding up the bottom. I added the tunneled X Brace. It has an integrated trans mount. I just did it because I wanted to. I entertained the idea of a new rolling chassis but I wanted to use mine and have the frame number. Johnny Law Motors sells the pieces as well as No Limit Engineering. I think NL is in sections so it's easier to handle. JL looked like it was the entire side.

I enjoyed doing it. The welding gets monotonous.

Originally Posted by drfloyd

This X Brace is from No Limit. I don't know if it will work on a trailing arm system, I have Rob's 4 link Fat Bar. I'm thinking is was around 600 with the trans mount.

I used 3/16" x 6" flat stock. I spotted it in as I fitted it and then welded it in all the way. I wanted a smooth finish when I am done.

I can't seem to find the X Brace on their website. So I called and talked to No Limit. Waiting to hear back from them about if they sell them anymore.

I bet it won't take much to get it to fit with the rear trailing arm kit.

[drfloyd]

They have lots of things that aren't on their website. I'm sure they still have them and that they can be made to work on a trailing bar setup. The brace is not a drop in fit, it requires quite a bit of modification to get it to fit properly.

[SierraMtns]

Originally Posted by drfloyd

They have lots of things that aren't on their website. I'm sure they still have them and that they can be made to work on a trailing bar setup. The brace is not a drop in fit, it requires quite a bit of modification to get it to fit properly.

Just curious why you picked the 4-link bar over their trailing arm kit?

[drfloyd]

IMHO and based on things I've been told by "experts": Training arm is better for higher torque and speed applications. 4 link is a better ride and is better for street applications.

[Dynospeed]

Im interested in going to the No Limit fat bar 4 link. What are you thoughts on it after having it?