Frame Boxing Question?

[MBL]

Hello all Tim here. Just a quick question about frame boxing. Does it make sence to box just the front? I am running a flattie which will be mostly stock. Not too much power. This boxing should take care of twist in the front...right? Does the rear really need this? Does the frame need cross bracing to stop it from shifting? In a rail to rail mannor?..Essentially to keep the frame square? Will the forces of the motor and movement try to pull it out of square or just try to twist? Any thougts? I am using a model a frame.
Tim
MBL

[LUKESTER]

If you got the time money and patience, I would. The boxing plates are sure alot easier to mount stuff to than the inside of channel. I dont really like nuts and bolts for wire clamps etc, going through the outside of my frame rails. and you can usually never overbuild.... use 3/16 plate and have it sheared to fit right inside your rails and its pretty easy. LUKESTER

[Dirk35]

I agree with Lukster. Its not like your trying to save weight here. Box as much of it as possible. Use plate the same thickness as the current material of the original frame.

[MBL]

Will doing this help it remain square though? Will it just stop the rails from independently twisting? Will cross bracing help or reduce the need for a box in the rear? I have looked at Marts site and the framework on Old Rusty seems well done. I don't see where it is boxed though. Again they are 32 rails and 32 K member...any thoughts?
tim
MBL

[fab32]

My experience has shown that you don't need to box the entire length of the rails on a low to medium hoursepower rod. I usually box from the front crossmember to about the firewall area (or back to the front legs of an X member. After that it is good to box from the start of the kickup to at least several inches behind the rear axle centerline. This strengthens the area where you will be mounting rear suspension locators and shocks.
I save the full boxing for high horsepower/high torque applications.
X members or K menbers will keep the rails aligned and square with one another

Frank

[Deuce Rails]

Hello, Tim.

I don't think that boxing the front would do much, only because the front end doesn't flex much. The distance between the front cross member and the K-member is pretty short. The real flexing goes on from the K-member back to the rear cross member. That's a much longer distance between reinforcing crossmembers.

How about making your own new crossmember (or two) and putting it somewhere between the K-member and rear crossmember? It doesn't have to be too complicated, just something that ties the two framerails together somewhere in that long span under most of the body. It may better to bolt it in, rather than weld it in, so there would be some movement.

--Matt

[MBL]

If you look at Mart's site....Thats what I was thinking for the rear rather than a box for the rear.
Tim
MBL

[LUKESTER]

Crossmembers square to the rails will not keep your frame from "diamonding"... or flexing... you should use X or K style stuff. Triangulation is very important, to building a nice stiff frame. if you don't have alot of horsepower, it probably doesn't matter... after all most rods are underpowered and lightweight. but in a perfect world you would want to triangulate your crossmembers and build it as stiff as possible. so you can keep the doors opening and closing nice......... LUKESTER

[Creeper Larry]

Just a thought- I have an A frame that was drag raced with an injected 283, the frame is bone stock cept for mounts and is straight as an arrow. If your not runnin big tires and are not gonna sidestep the clutch@5000rpms, I would leave it stock. The flathead would break long before the frame. Got to figure a flathead isn't high up on the horsepower chain. I don't think the torque would pull the frame off square, if anything it would possibly twist. Again, not with a flathead. Just a thought. Larry

[MBL]

Ok....so there is many schools of thought here....Keep em coming! Thanks for this input.
Tim
MBL

[NealinCA]

I have a question on boxing.

My 32 frame had been fully boxed for a race car. All of the stock body mounting holes were welded up. I was thinking of cutting some access holes in the boxing plates to get to the body mounts, etc.

Would something like this be OK?

[Creeper Larry]

Get the Bishop Tardel book on Biuldin a Ford Hot Rod. It has a good section on this. He uses a 32 K member modified to fit (with blueprints)the A frame. Only drawback is you have to pull the motor just to get the gearbox outwith the 32 K member. If you go with a 33-4 style X member you can get the gearbox out with the engine stll in. Also the 33-4 style X member would be really strong, and looks kinda cool.

[MBL]

I thought he did not box the frame in that book?
Tim
MBL

[36-3window]

i think boxing a model A frame the full length is the only to go,even with low horsepower engine.weld the front and rear crossmembers in,and add a K-member in the middle. the k-member can also be set up for a rear transmission mount. i say this because the stock frame flex's like an old bed frame. making the frame more rigid will make the finished car ride and handle better,the doors and body panels will fit better and stay in alignment. the twisting force on the frame will not be transmitted to the body,keeping the body mounts from getting ripped up.

make sure you get the frame level and square before you do any work. if you spend the time and effort now to beef up the frame you will be glad you did later

[Creeper Larry]

Neal- I had an A frame trhat was fully boxed, whoever did it cut small halfmoons from the toprail down.They were about 2" long. Seems like a good way to do it with, minimal work? Larry

[Creeper Larry]

MBL- Exactly! He did not box the frame.(Tardel)

[36-3window]

[ QUOTE ]
I have a question on boxing.

My 32 frame had been fully boxed for a race car. All of the stock body mounting holes were welded up. I was thinking of cutting some access holes in the boxing plates to get to the body mounts, etc.

Would something like this be OK?


[/ QUOTE ]

i wouldn't cut holes inside the frame to access the body mounts.after you fit the body on the frame,mark and drill the holes and then just install nutserts after the body is off. this would look a lot cleaner.or if you don't like nutserts,weld a threaded bung flush with the top of the frame rail.

FYI....SO-CAL doesn't drill the holes in their frames. you have to drill and tap them yourself ,but they have a 1/4" strap of metal welded underside the top of the frame rail for this

[MBL]

Alot of interest in this subject! Any of you who have been following my project may know that I have put it together and broken it down like 100 times to get all of the measurements right....We have made some mistakes and have fixed them.....We are doing it the only way we know how. My frame is not the best though...it is what we have to work with. I do want to box the front part of the rails. Mostly to reenforce areas that have some rust pebbling. Its not overly bad....but I would be more comfortable if we did.
Tim
MBL

[MBL]

Sinner had thought of an idea to put like smaller metal triangles in welded to areas where the crosmembers connect. Like the ones on the stock Model A rear crossmember. This would be behind the middle crossmember or maybe in front as well. Any thoughts?
Tim
MBL

[Deuce Rails]

[ QUOTE ]
Sinner had thought of an idea to put like smaller metal triangles in welded to areas where the crosmembers connect. Like the ones on the stock Model A rear crossmember.

[/ QUOTE ]

Hey, that's a gusset!

Sure it would work.

[Nick32vic]

I dont know if these will help any but we made our own boxing plates and crossmember. We are using a 302 not high performance but we still wanted to be on the safe side and make sure nothing bends or twists. Here some pics.

1.

[Nick32vic]

2

[Nick32vic]

We boxed almost the whole frame.

3

[MBL]

Thats Nice work...but definately more than we were planning to do. .
Tim
MBL

[Nick32vic]

Ya, im sure you wont need that for a flathead but i thought you might like to see.

[Paul2748]

I'd box it all the way. Model A frames are not the strongest and were not designed for any kind of V8. I had two cars with a A frame and boxed both of them fully. It's also easier to mount your gas and brake lines. I used reqular Adel clamps to mount mine, just drill and tap the boxing plate for a #10 screw.A 3/16 plate will give you enough threads. Boxing the whole frame will give the body more stability. Current car is a glass 27 T with a A frame. When I first got it the body was starting to crack in some places from flex. After boxing there was none. It's flathead powered.

[Mart]

I added the x bracing to my frame after riding over less than perfect roads in Vern Tardel's Deuce roadster, that old gal flexed and twisted over every undulation. (AV8 describes it as "leuce"). Loved every twisting inch of the ride though.
My body hardly twists at all, It was amazing how effective that relatively simple and light bracing was.
Nealinca: If I were doing as you are suggesting, I'd use a hole saw the same diameter as the height of the cutout, and cut between adjacent holes with an angle grinder to make the slots. Might be easier than the four cornered holes as pictured. Just a suggestion.
Mart.

[NealinCA]

[ QUOTE ]

Nealinca: If I were doing as you are suggesting, I'd use a hole saw the same diameter as the height of the cutout, and cut between adjacent holes with an angle grinder to make the slots. Might be easier than the four cornered holes as pictured. Just a suggestion.
Mart.

[/ QUOTE ]

Mart - I was acually planning on doing the holesaw deal, I should have explained that along with my quick and not-so-accurate drawing.

Great minds think alike http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

Thanks,

Neal

[Tim]

on that note you could save your blades and make a template out of something ceramic, like a floor tile, make a template of your hole find a plasma cutter and have at it.

nicely shaped holes, squares stars, whatever, and saved 30 hole saws and 11 blades:)

tim

[C9]

It's not just the horsepower.
Try entering a driveway at an angle with a somewhat flexy frame and you'll find a lot of body shifting as well as body components rubbing together.
Not to mention the dreaded "roadster pinch" when the skin on your arm gets pinched between door top and top front of the quarter panel.

Box the whole frame rail and get it over with.
Somewhere down the line you'll be glad you did.

Nick32Vic is on the right path, but to my eye the two pieces tying the frame together as well as the flat plate trans mount don't tie the sides together well enough.

What would help here - in my opinion - is a 2 1/2 x 3 1/2" x .120 wall crossmember located for seat belts and a future mount for a roll bar lateral if you decide you want one.
My 32 has similar frame construction to Nicks, but is 1 1/2" x .120 wall round tubing.
With a total of six crossmembers in the car which includes front and rear as well as a 1 1/2" round muffler hanger bolt on crossmember.
The frame is very stiff and the body creaks a tiny bit, but body shift is very minimal entering a steep driveway at an angle.

My 31 on 32 rails roadster - which was slated for the dry lakes - and which I wanted to have a very stiff frame has seven crossmembers including front and rear, but does not have a 1 1/2" round tubing muffler hanger crossmember like the 32 does.

Stiff is always better they say....

[voodoo]

[ QUOTE ]
I thought he did not box the frame in that book?
Tim
MBL

[/ QUOTE ] He did not need to box as he started with a super clean unpitted frame, left the center cross member in and added a 32 k-member. Three things at least that you don't have.

[286merc]

This is another one of those topics that gets beat to death every few months.
Take a look at Daigle Street Rods X member for an A frame. The picture is good enough to build from.

Another option is to cut the X out of just about any fat fendered Ford. Then section it vertically to fit inside the A rails. If you are lucky you will be able to salvage the rear part from both sides. Note that the stock X continued INSIDE the stock rails all the way back.
I used a 39 X and redid the front tunnel for a C4. The rear was rotted so I boxed with 3/16"; the same as the front. Looks more traditional than the newer ideas used for big engines.

[Jive-Bomber]

Tim-

We boxed my A rails the whole length to be safe, since I'm running a 700 lb motor. I'd like to add an X member later, but the chassis seems to be pretty durable for now. I endeded grinding and modifying my boxing plates quite a bit because of dings and bends in the frame rail edges. Just take your time and do it up on a solid table or jig.

[Jive-Bomber]

better angle...

[av8]

Fighting the dreaded frame twist has taken on a life of its own over the last few decades. Whether or not boxing is needed has as much to do with suspension attachment as it does the horsepower/torque on hand.

We didn't box the frame on the blue roadster because we felt there was no compelling need for it. With the original spring and axle-control connections along the longitudinal centerline there's precious little force to twist the frame when quartering driveways or running on uneven road surfaces. it's a very different matter with split wishbones, hairpine, or four-bar fronts, as well as with coilover rear suspension. These schemes do apply twisting forces to the frame.

The blue roadster wasn't a twister, thanks in part to the whittled-down Deuce K-member we installed. Doors did not pop open nor did they fret and chip paint at the pillars. Even the relationship of the radiator shell/hood/cowl was stable with no discernible paint wear or chipping.

IMHO I think selective boxing is not a real good idea. It creates "hinges" where the boxing ends; the torsionally stiff boxed area no longer flexes, but the unboxed area does, and the juncture of the two areas gets a real workout and can eventually fracture at that point. Fishmouthing the end of the boxing plate will radiate the load so it's not concentrated at a single point on the frame, but even that doesn't completely eliminate stress being concentrated in a small area.

BTW, for you un-flatheaded folks kissing off the unspectacular horsepower numbers of the old motors, they put up some impressive torque figures that, compared inch for inch, will hold their own with more-modern jiggler motors. They do indeed have the ability to twist things and break driveline pieces.

Finally, if I were doing a Deuce frame, I'd find a '33-'34 X-member and carve it down to fit in the '32 rails. I'd also look long and hard at the idea of running front and rear wishbones, with everything connected to the longitudinal centerline.

[Mart]

Just checked out the other pics, and the other replies, (only had page 1 up when I wrote my first reply).
An A frame is shallower than a 32 frame, so maybe there is a good reason for boxing, just to add strength generally, as well as improving the resistance to twist.
I'd be bold and say the boxing plates do not need to be as thick as some have suggested. The unboxed frame is sort of almost strong enough, some 2mm plate (3/16" = 5 mm) would add plenty of strength with less than half the weight. Or 1/8" (3.2mm) if you're nervous.
Obviously you need to attach crossmembers to the main rails, not to the boxing plate.
Jive Bomber, don't want to diss your work, but there's no way that frame will resist twist on driveways, let alone with a big motor.
The rails are boxed, and individually will not twist much, but the stock A centre crossmember has gone, and the remaining crossmembers are just channel, (can't help that, that's the way they are,) and will do all the twisting, the trans c/m is not substantial enough to resist twist.
I aint trying to tell you what to do, but If it were me, I'd jack up one front corner, where the radius rod meets the axle, until one of the three wheels on the ground just about lifts, and measure the angle across the frame front and rear. That way you can calculate the twist as a base line. I'd then add a top and bottom x brace (just tacked in if unsure) and repeat the exercise. I think you will find the twist angle substantially reduced.
The benefits will be a better handling car, plus better body fit, with less rubbing, and if anyone has experienced roadster pinch, just eliminating that is good enough reason in itself.
Please view the above as constructive criticism, other than the above comments, the frame looks great.
Mart.

[ChaletStacker]

Tim you need 2 box the frame all the way, your frame
is not 2 strong as it is 2 start with. Then addin
cross members will stop twist where needed. your
flatty might be stock but its a lot heaver than the
4 banger with more power.
(But what do i know, i'v only biult three.)
good luck. Mark.

[MBL]

Well I was looking at the thing this past weekend...and well with the torque tube where it is....its gonna be hard to get cross bracing to work well. So with that I guess the least that we could do is box the the whole frame... Its not going to hurt anything for sure. We will probably add the gussets as well.
Tim
MBL

[modernbeat]

You're keeping the torque tube? Are you splitting the bones? If the drivetrain is all stock (keep the torque tube, and unsplit bones) then you definately DON'T need to box the frame. If you keep the suspension and drivetrain mounting points in the stock locations they don't apply any twisting force to the frame.

If you run split bones it's a different matter.

[MBL]

Front are split and rear are not.
Tim
MBL

[trey]

on my 28 dodge, we are boxing it in all the way. i will be running a mild 283, but id rather be safe than sorry. if one day i want to throw a blower in it or something, i can. figured id go ahead and do the extreme while im at it. also, i welded my plates for boxing a little outside the frame. i just think it looks cleaner when done, instead of setting them inside. no offense to anyone or anything.

trey

[ChaletStacker]

Its better 2 box all now,so if u want 2 hop up
your flatty at a later time it will be easyer
and save time and hard work.Hows the steering
box fitting now.

[SlowLearner]

Thought some of you might be interested in some old “factory” boxed (weight be damned) framing practice. Not sure how can translate to an “A” frame. Henry really did save weight with his transverse spring arrangement!

On my ‘36 Packard chassis the front rails (only) are “boxed”. Actually, a reversed (slightly shallower) channel section is riveted and welded inside each front rail. The (channel) inserts then emerge from the side rails and gradually converge to form the sides of an X member. Kinda elegant in a stone henge sorta way. Then, the X member is tied together, and to the side rails, with a humongous plate rivetted across the top (but only half the bottom).

The boxing channel and X member has large holes in it (an attempt at lightening?). The shallow (gradual) transition from front box to X member may answer some of the concern that av8 pointed out about partial (only) boxing, causing a stress point. By the time that the X member is joined across the narrowest point in the X, the side rails are 8” deep. Think of a raft of girders.

I’m posting a coupla pics for interest’s sake. Please forgive the bumpers and crap lashed to the chassis right now. Got high hopes.

http://photo.starblvd.net/~SlowLearner/2-2-4.jpg

[SlowLearner]

Further in.

http://photo.starblvd.net/~SlowLearner/2-2-5.jpg

[SlowLearner]

X member.

http://photo.starblvd.net/~SlowLearner/2-3-1.jpg

[SlowLearner]

Ooooops! SORRY, killed the thread. http://www.jalopyjournal.com/ubbthreads/images/graemlins/blush.gif

[dv8]

You didn't kill it....He has a Packard also (55), and he probably just got really confused. (That happens alot with MBL) http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif

[MBL]

Killed? don't get it...either way we will probably box the whole thing. We have to tear it all down anyway; so we might as well. It can't hurt anything by making it stronger. I think though that we may try the whole gusset thing in addition....in an attempt to keep the frame square.
Tim
MBL

[dv8]

See. I told you he was confused. http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif

[slacker_53]

MBL...I'd box the hell out of it. It's probably going to be easier now than later........You may decide to do away with the flattie someday.

I change my mind all the time......what mind I have left