Just starting in on the frame for my '31 Ford Coupe. I had the frame sandblasted yesterday. Thinking that rivets may have worked somewhat loose over the last 85 years I've considered welding the joints that are now just riveted (frame rails to crossmembers). The frame is in surprisingly good condition without any significant pitting, and it measures good as far as being bent or twisted, so I don't want to weld the joints unless there's good reason. If I were to weld anything I thought I would limit it to the joint where crossmembers and the flanges of the frame channel meet. So, what's the popular concensus? Lynn
If you are going to put a modern higher horsepower engine/trans/rear in it, I would box it and weld the xmembers.My 2¢
Depends on what kind of Power and rear Tires your planing to run. They were built to Flex in stock form. Welding at the crossmembers stops the Flex at the welds. Now you will get cracks at that point. That's assuming you can plant the rear Tires enough to make that happen. The primary reason for the design was due to road (or lack of) conditions back in 20's and 30's. The Wizzard
Before I would go through all the work of bringing an Antique Frame up to big motor and big tires standards I would hand build a New Chassis using Rectangle Tube. It's way easier on a Model A than boxing and finishing a Stock frame. The Wizzard
We have paved roads today and not deep rutted out hog paths to drive on, the frames in their original configuration were designed to flex but they were never meant to be subjected to the kinds of horsepower we decide to shoehorn in place. I've built several Model A's in the past and I am a firm believer in boxing the frame to make it structurally safe. HRP
I'd agree that unless you plan to box the frame and stiffen it leaving it just riveted is probably the best go. The frame being able to flex and move is/was part of how the suspension worked on the older rigs. Now that we have far smoother roads and a Model A hot rod isn't likely to make an off road trek up into the woods on logging roads we can stiffen up the frame a lot.
I noticed many replies seem to expect the car will be built with a modern, high(er) HP engine. That's not the case. I'm using the Model A 4-banger and warming it up to hopefully 55-ish HP, backed up with a RTS-170 overdrive and the Model A banjo rearend. In any case, I don't plan to hold the RPM up and side-step the clutch. The car is intended to be what I would call a "beater". As I mentioned, the welding I had in mind would be limited to relatively short "stitch" welds maybe 3/4" long where crossmembers meet the frame rail flanges. I'd see them more supplementing the rivets than anything. Lynn
With a banger in it I wouldn’t worry about the frame, put it together and drive it! If there are obviously loose rivits replace those. Sent from my iPhone using H.A.M.B.
I like your Build direction. My advice is, "don't over think things" and "don't re engineer Henry's design". How long has it lasted to date and it's just fine. If the rails need a little maintenance, meaning tighten or replace a couple rivets, do just that and move on. You'll be just fine and so will the Car. The Wizzard
I agree with your decision. If its going to be relatively stock you will probably be ok like it is, there are thousands of them running around like that.
IMO... sight down the rails before you box anything, they tend to sag at the rear motor mount... pooches the hood to cowl or hood to grill gaps... having [14] or so rivets on the crossmember spreads out the impact, less apt to crack, unlike welds... ...'28 1 ton trucks used a car size front crossmember but it was 1/4" thick as to 3/16" cars... recognizable by the 2 large rivet heads, they hold a reinforcement strap under the member...
Frame rails appear straight when sighting down the top, however one rail was bowed in and the other bowed out a similar amount at the rear bellhousing mount. I had that tweaked on a frame table by a friend who owns a body shop. It's still not quite perfect, but the frame measures good when "X-ing" it. As screwy as so many things are on this A, I'm surprised at the good condition (negligible pitting) of the frame. Lynn
I have a Model A frame I'm working on. I have a 2.5 S10 engine to go in it. Even if I was putting lawn mower engine in it the whole magilla would be done to it, including a narrowed 9 inch Ford rear end. I have been scrounging up parts for it for a couple of years. Why go ape shit? They say women change their minds a lot. Hot Rodders have them beat by a parsec. Thing is building stuff is work. I theorize if you can out think yourself, then go for it. I grew up welding. I have nothing against rivets. NYC is full of buildings riveted together that have been there long to prove that they work. But, when you drop a body over all that good stuff only someone under it is going to see it, and if you put mirrors underneath and some Angel hair down there you're not out beatin' on it. 'Cause the deal is like Lil' John told some Yo yo. "I drove; and you want to bet money i didn't, I got a speeding ticket to prove it." Or to that effect, so I read. My point being don't out think yourself. Getting in a Hot Rod and firing up the engine does stuff to you. You take a ride and come back with your adrenaline pumped up and it does something to that little voice in your head. Faster would be a whole lot more if it went faster. And, suddenly, you have the need for more speed at the wheel. If you're on the beam and getting a clear signal the first time you take something apart and stand there wondering what the fook to do, think how fast you want to go and fudge upwards. Then build a Rod that is safe, comfortable (more is better), that will stop on a dime and give you five cents change, important to the nines: it will go so fast you won't want a speeding ticket, and finally something many people miss. Be sure you have it all harmonious so it won't fall apart because you went cheap on the parts. Anything worth doing is worth getting into the industrial strength area. Not good, not better, but the very best you can afford. Otherwise, like Candid Camera some day, some where you will realize that, and the worst part is that you will regret it. If you think this is extremely, wait a while.
Riveted together frames flex quite a bit in my experience. One of my buddies has a driveway that comes down from the crown in the road, up to a steep incline of driveway. I boxed the frame on my 35 Ford PU and it was solid enough that if I went at too steep of a driveway at an angle, the rear wheel would come off the ground once the suspension travel maxed out. When I would jack up either side to change the front tires, the whole side of the pickup would raise up enough to lift the back tires off the ground also. Conversely, my 34 frame is only boxed at the front from the firewall forward up to the back side of the front cross member, and the back is boxed behind where the X member meets back at the frame to the end of the back frame rails. It twists a little on a really steep driveway and I can see the effect in the door gaps (I don't have any weather stripping in it yet and can see the light in the door gaps), so Ill probably box the rest when I pull it all apart for paint.
Oh yeah, my 34 frame is boxed pretty much the same as the Coupe in this thread, but my boxing plates don't touch the X member at all, they end right before the X member. I also don't have the upper plate between the to rails of the X member like he has, I just have the aftermarket transmission mount plate bolted to the bottom of the X member, so his frame will have more rigidity than mine. Ill probably also add a upper plate like they did. https://www.jalopyjournal.com/forum/threads/34-ford-coupe-nicknamed-blown-income.1087068/page-3
Boxed my frame and welded the x-members since the frame was no longer expected to flex. Kept the rivets for looks.
Ultimately it will be the OP's call but this is exactly what I was about to recomend. Many years ago a friend and fellow worker bought a Model A coupe that had passed between a couple of real hashers, it was so bad that I suggested this very thing, he apparently listened because when I came back to work from disability; I walked past the big steel dumpster and there was that whole cobbled up mess in the pile of steel. All he saved was the body, he had called my friend that built my roadster chassis and ordered a complete fabbed frame, it really turned out nice.
I kept the riveted crossmembers in my four banger Model A build. I did drill out the rivets in the front crossmember and rivet in a better front crossmember. The crossmember is subject to stress cracking in the hidden area of the main rail sides. Thus, it was good to remove and check the crossmember. I did some crack repair in the one I used. The transmission’s semi-solid mount tightens up the frame flexibility once the motor is mounted. A sixty horse +/- banger will not be too much for an original style frame in my opinion. I am also using the F150 three speed with OD transmission which work with the closed driveshaft Model A banjo rear end.
i am building a '32 frame, new rails, A crossmember, drop-out tranny mount, rec. tube rear crossmember, boxed from 12" before the firewall to 12" behind the firewall. and about 3' from just before the kick to just after it... I want to let the frame flex a little...
My 32 is boxed is a Henry frame boxed front to rear , A front crossmember . I had an old book many years ago “how to build a hot rod “ Jerry Kugel , boxed and used 2x2 and 3x2 for cross members , mine is copied from his design . It is sold as riding in a new car , no unwanted squeaks and rattles. I have seen many way cooler looking , as in 40ish. X member , A or 40ish rear crossmember. But mine works and I was young , I did what I had access to . The steel came from Stewart Iron Works , it was scrap from building jail cells .”.30 a pound we cut it to size you request . “ This worked real well for me . 20.00 got me lots to weld up and kept the family in shoes ! They build cell bars in Alcatraz (?) . It guess it all goes with my name !
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