I've decided to make my own frame for my 34 ford truck and I'm treading on new ground here so any suggestions are welcome. Here is what I am working with. speedway 48" 4 bar tube front axle spring behind. 2x4 3/16 steel ( probably should have gone with 1/8 ) I want kind of a short 28-31 bed on it. 45-50" the cab from firewall to back is 48" 33" across the firewall 40" across for the bed I would like to keep the engine bay as compact as possible with a 351w so 43" from firewall to front of radiator. 26" for the front crossmember. I am thinking of 60 degree kick up in the rear. I'm no cad designer but I thought I would try and learn autodesk inventor and this is what I have so far. what kind of space is everyone leaving for an engine bay?
Looks like you have a good handle on it. But here's a link to my 34 pickup build thread maybe it'll help you out. http://www.jalopyjournal.com/forum/showthread.php?t=368357
What wheel base are you shooting for? If I remember correctly a stock model a was 103. When I built my model a sedan I built it for 106" wheelbase. here is a link to that build. http://www.jalopyjournal.com/forum/showthread.php?t=207336&page=5&highlight=bat+cave
I've done this with a '26 roadster body. Wheelbase ended up at 117" because I allowed room for a 460 Ford/C6 and all the factory OEM cooling system components, suckin' through a new Walker copper/brass radiator. I mocked up the body, differential with suspension, motor, trans and then just "connected the dots" with 2" x 4" x 0.120" wall rectangular tubing. Building on a stock wheelbase and then having to jump through hoops for the cooling system just makes no sense to me.
No traditional hotrod ever started out on a CAD program. Put the 'puter away and get out your torch. Find any old 30s Ford frame and start building it.32 up to '48. The later ones need cutting down but are usable.You want to be driving a Henry Ford not a Bill Gates don't you?
Mat, your build defintly helped me out. Tin Can, I think Im shooting for 109. I just have to see where the front end end's up being and how long a bed I come up with. Thanks for the baseline fridaynightdrags, what was your engine bay measurements? I might want to go big one of these days also. Id love to have a 427. edwardlloyd, thats what I usally do but end up doing things twice. Its much easer to change your mistakes on CAD. I do appreciate what you are saying thoughl Ok here is a question for you. Which miter joint is stronger and is it ok to do a compound miter in the bottom z of the frame? I've decided to do a 65 and 4.5 compound miter at the bottom of the z. Which would be better?
Designing a frame is a good exercise to learn Inventor, go for it. I would get a copy of the original frame, try Wescott's they have earlier prints and maybe the '34 as well. Make a cad dwg of the factory frame, you'll learn that the frame don't have straight, plumb and true surfaces. When you learn why Ford designed thier frame the way that they did then you can design yours. When you actually design the frame you start with the suspension points and then add the frame members to satisfy your requirements. When making the dwg the actual frame rails are drawn in 'after the fact' so to speak. Figuring everything out is easy if you use your noggin, for instance figure the front tire is 26", rear tire 28" so the front spindle will be 13" and the rear is 14" - from taht you can figure where your suspension points will need to go (you've got your front assembly sitting there so you can just measure it, right? The rear axle you have to select because of pinion location varies); i like a low car, i'd set the crankbolt about 13", that will give you about 5" under most oil pans, now you know the centerline of the drivetrain - the crankbolt is the middle of the crank, then thru the tranny etc so all that is 13" at the tranny tailshaft if you set the engine etc level. Once you determine what engine/tranny etc then you'll have some lengths. Those lengths will tell you where the crossmembers need to be. Get the picture? You don't start with a couple parallel 2X3 frame rails - you are developing some Inventor skills and that program (i have an old version) is a trial. Doing a frame is solving a logic problem: solve for the known and the unknown will solve themselves. Good luck, oj
OJ, you've done this a time or two havent you. Everyting you said make perfect sense. Whats your opinion on the compound frame miter ? I not an engineer and value the opinions of both those who have been there done that through hard knocks and professional training in school.
Ok great. One more question. How much room do i need between the top of the rear axle and the bottom of the frame for suspension travel?
Before you start cutting any steel, build the frame out of 2x4 lumber to make sure it looks and fits right. If something needs to be changed in the design, best to find out before any steel is welded up.
I kind of agree with EDWARDLLOYD. I started with a 35 40 frame because it was what I had. Not necessarily right, just how I did it. 111" wheelbase.
It depends on what you are doing for rear suspension to figure out what distance you need from the rear end to the bottom of the frame. If you are running coil overs get the ones you want and figure out what you would like your mounts to look like. I was told by a reputable builder to allow for 3" of suspension travel in the rear.
I'm planning on 4" travel. Potholes are everywhere! If your ride is too stiff, then later you still have the option of taking out a spring and not lose needed clearance.
Airbags with maybe 5 -6 inch of travel. So good rule of thumb would be 3-4 inch for rebound to be safe.
Are you serious?? One of the best chassis builders on here does it all in CAD first. Don't see anyone putting ELpolacko down for it. Next thing is we will have to weld everything with gas and cut it all with a hack saw.. lol
Ive decided on 65 degree miter and not to compound it. Im going to cut a 4.5 degree relief in the frame and re weld it just before the kickup. It just makes more mechanical sense and seems safer to me. I've stopped stairing at it on the computer and starting to cut some steel so here goes.
Wheelbase 117, measurement from firewall to centerline of front wheels, 43.5". Mount the radiator at exactly the centerline of the front tires for the best look from the side of the car.
jydog - here is some pics of my frame and body skelaton - still a work in progress but dont fear making changes as you go - it metel - you can always weld it - jaxx
I don't think he meant to put anyone down at all...but he IS right! It's a Traditional thing and this IS a traditional board after all! Most of the best loved Hot Rods ever built were designed by the builders eye, a bubble level and a length of string...then constructed from recycled parts. I'll admit Plasma cutting, MIG and TIG, CNC machining, CAD... sure is convenient and faster if you have it. But lets be clear. Thats ALL it is!!! I'm absolutely SURE El P wouldn't insist his CAD programmed frame designs are "traditional" and I'm equally sure he wouldn't insist that designing a frame without CAD is a guaranteed recipe for disaster.
I have never got into this "traditional" thing but, I think you have gone too far.............. Use the best stuff you can, period.
My point was that we should end up with a trad looking car. That doesn't mean we have to go back to the dark ages and use all the tools they had then to get it done. That would be kinda crazy, considering what we have available now re tools, materials, etc. I'm sure there are plenty who don't agree with me, but if you do it exactly as they did back then, I would only guess we are only restorers and not Hot Rodders.
Don't listen to the self styled "traditional police" this time around. Hot rod builders have always used the best stuff they had available at the time an if you can use cad to see what it looks on the screen before going out and doing it in the shop it will save a lot of headaches and mistakes out in the shop. I agree 100% with the suggestion of mocking the frame up with 2x3'stu or other lumber the right size. A few Home Depot cheapie 2x4's to mock it up are a good investment to see if things will work and look the way you want them to before you cut up a couple hundred bucks worth of metal. One thing, when you cut your tubing make positive that you cut the main rails so that the weld seam in the tubing goes to the inside so the seam won't show on the outside of the rail when you are done.
CT...I think you misunderstood what I meant. I'm not suggesting inferior tools be used...just that the tools used back then WERE up to the task and a person with the knowledge to use them could make a safe and reliable car. Todays tools are only an improvement in speed and personal comfort. Use a torch, a hacksaw or a Plasma cutter, the end result is a piece of metal cut. Plasma...easy, fast and clean. Torch...fairly easy, fast but usually needs cleanup grinding. Hacksaw...Not easy, slower...but still cut! LoL Hi Tech tools...If ya got 'em...use 'em for sure! But don't consider them an absolute necessity. Gotta remember...this hobby grew from the shoulders of a lot of guys who likely would have considered a Pop rivet gun Hi Tech and it didn't hold them back a bit! Lifestylz...I get where you're coming from...and I disagree only in that its really personal choice...not an example of bad building vs good building. The old ways were good IF done correctly...as it is today for that matter! LoL We just have a different way of looking at it is all. Personally...I dream of those dark ages you mention and would love to have the knowledge to use only their methods and tools to the max. There's just something about the rawness of something old and Hot Rodded long ago that grabs me and draws me in. New computer designed stuff just doesn't do it. I don't think that makes a person a "restorer"...just... traditionally biased? Again...personal choice and not worth hashing out...because ultimately everyone is happy in their own world anyway! Hahaha Have a good one guys!
You got the right idea, JY, i'd suggest setting your doby down on the floor and then painting around the body. When you lift your body off the paint will form the perimeter, then form the frame rails to set inside the body by about an 1", when you get to the cowl pinch the rails up to the axle as you have done. The difference is that by forming the rails to contour the body you can channel the body over the rails and then make a pocket in the floor so the seat is below the top of the frame rail. If you leave it as you have it the seat will have to be on top of the frame rail - thats ok if you are building a highboy, but if you are dropping frame then you will sit too high in the cab.
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