How to build an early hotrod frame

everytime I read this I learn

Thanks Brianangus!!!!

 

MadJack---I have never used a dead perch.---(Although after a day spent in the garage my wife has hinted that I smelled like one!!!)

 

great information I can't stop reading this thread.

 

Hello:

I have seen the draws you made for you pick Up bed, i think you are using SW.
Any chance you bring me your model for this roadster.

Iam making studys in Some draws available in internet and some picks to model a door but I have no real reference on the curves of the door. How do yo model the door in this roadster, straight or curved??.

If you are interested I can send you my door model. lrapso@yahoo.com

 

Hey brian great thread thank you for posting it, looks like it's helping out a lot of rodders and answering some of those questions that we never seem to get a 100% clear answer to!

A couple of things i didnt see mentioned here, form is sometimes more important than function in hot rodding. That also goes hand in hand with $$$$, im not saying cut corners but, sometimes we have to use whats at hand, that being said, use this thread and what Brian explained to build a safe, well engineered chassis!

Concerning the front suspension ie. straight axle and either split bones or hair pins it was mentioned elsewhere in this thread that when using traditional steering either a frame or cowl mounted steering box,that the bones or hair pins where they pivot at the frame attachment, should be the exact point where the steering arm joint pivots. Generaly this should be the goal as this helps to if not eliminate all bump steer, since most hot rods are lowered and suspention travel is minimal, one can get away with the piviot points being abit off. With a cowl mounted steering box you can't do this so atleast make them as close to the same length, there it is again form over function, and this will help to minimize bump steer.

Regarding the rear suspention and spliting the rear bones, or making hair pins you state that you want to keep the mounting points as close together as possible to eliminate rear axle bind and this is right on. If you want to run them further apart, or on the outside of the frame, on say a high boy, (form over function) keeping them as long as possible will help to eleviate axle bind and hair pin twist. This bind front or rear, only happens on uneven ground ie. Driveway entrances, cambered roads and such, most suspension travel is a uniform vertical and bind never really comes into play.

 

Excellent thread. Some of us think we know, have learned, a lot in over fifty years of building, but every so often, along comes someone who throws out some new ideas.

 

AAAAAAAAAA+++++++++++ to you Brian, I just started my first build and you and the help of others prevented me from some ideas i had that would kick me in the a$$ later. Thanks Jason

 

I just want to say that after hours of searching, this is the thread that I have been looking for.
Thank You....

 

btt. for all this delicious information.

 

This has to be the best thread I have seen in my short time on the hamb. This is info I wanted to read since I signed up. Brain and everyone else who has contributed to this thread are stand up men! How do I save this, as I can see it taking on a life of it own?

 

I can't believe how many times this comes up.
It is a great thread.
Thanks again Brian, I know I've read it 3 times.

To save this ath the top where it says quick links, click on that and suscribe to this thread.

 

For what it's worth I used front and rear 1/4s on a car two years ago . I don't know if this pic will help I'm not to computor friendly. Anyway lower link was half a 57 chebby rear leaf mounted on underside of A frame boxed,top link was direct thread tubing. We put quite a few miles on it ,my only regret was not useing a rubber bushed end and eliminate some of the harshness. best of luck

 

Rex has emailed me and asked the following question---
"I forgot to ask you about the upside down cup looking things that you have welded over the shock mount over the rear coil springs. What is that for? The plate that the cup is welded to unbolts? How do you get the coil spring back out if need be? The coil springs are dodge neon? What years? Do you happen to remember how much space you set the spring plates at while mocking this up? How much sag do you get once the bed and stuff is all together? "

Rex---you need to go back to post #20 and read it again---slowly--and look at all the pictures. When I was building this chassis. I wanted to have some means of adjusting the ride height of the finished vehicle, in case the springs compressed too much---and I didn't want to mess with adjustable bracketry on the rear axle.---So--First I welded a square 1/4" plate to the inside corner of the frame on each side. then I got a pair of coil springs--They may have been Dodge Neon, but it was 6 years ago, so I'm not sure any more. --However, any small 4 cylinder car with engine up front will have about the same weight in the rear as a steel (or glass) model A Ford, so as long as you go early enough to find one with coil springs in the rear instead of McPherson struts, you should be okay. I found a piece of pipe with about a 3/16" wall that was just big enough to let the spring fit inside it with about 1/8" clearance. The bottom one was welded to the axle-The top one was welded to another square piece of 1/4" plate which was then bolted to the underside of the plate which was welded into the frame. That way, if I got the car finished and the springs compressed too much, instead of having to torch everything apart and start over, I could put a spacer in between the plate welded to the frame and the plate which had the "spring cup" welded to it, to raise the chassis up higher. I can't remember now what length I had the temporary spacers cut to that I had between the upper and lower spring cups. Best way is to find a donor car, measure the spring while it is still in place supporting the cars weight, then pull the springs out and measure their "free length"--That will give you a reasonable idea of how much they will compress under a similar load.--So you can build temporary spacers to the correct length and use a piece of threaded rod to keep everything together during the chassis build. (Again--see pictures in post #20.) I couldn't find shock absorbers short enough to fit between the top and bottom spring cup plates---Remember, the shocks should be at mid travel when the spring is at its "natural ride height"---(which is the length your temporary spacers should be.)---So, seeing I had clearance between the top of the frame and the underside of my truck bed, I cut a hole thru the plate welded into the frame and thru the center of the plate welded to my top spring cup, large enough to let the body of the shock absorber pass thru, then welded an "extension tube" with a large enough inner diameter to admit the body of the shock, with about 1/4" clearance onto the top of the plate which was welded into the frame. then I welded a piece of 1/4" plate to the top of the "extension tube" and drilled a 3/8" hole in it to hold the top of the bayonet style shock. How do I get the spring out?--If I have to, I unbolt the shock at the top and bottom spring cups and jack the chassis up while leaving the rearend on the ground. this will let the spring cups seperate enough to pull the spring out sideways---same method is used when replacing the shocks. Those springs are just "setting" in the cups---they are not attached to anything. The shock itself serves to keep the spring in place on really wild and crazy bumps where the chassis might conceivably leap up high enough off the rear axle to let a spring jump out of the coil cups. I know this is a lot to take in--study the pictures. It works, and works very well, but it takes a bit to figure out whats really going on there.---Brian

 

I didn't notice that the plate with the spring cup was under the plate that was welded to the frame. I also didn't notice that there was a plate on top of the plate that is welded to the frame meaning 3 plates. There is no pictures of the shock bolt and nut attached to the cup on top so I wasn't sure why the cup was on top. I sure get it now.
Thanks,
Rex

Rex--You're still not "getting it". There are not 3 plates---there are only 2. One is a plain plate welded into the frame. Below that, and bolted to it is the only other plate, and that plate has the spring cup welded to the underside of it. the 'extension tube" which holds the top of the shock is welded to the top of the plate which is welded into the frame. I am posting 3 new pictures here, and one of them which has the box installed and the mufflers shown you can see the top of the bayonet style shocks
bolted into place (actually you see the rubber bushing, large washer, and nut).

 

Brian there is so much info here its going to take a while to absorb it all so I want to thank you for this thread.
I am starting my first build of a hot rod so please forgive any ignorance I show.
This is my question....The car I'm starting with is a 1927 Chrysler 4 door. It has a very beefy frame and I was planning on using it . It however uses front elliptical leaf springs which would make for a strong and sturdy setup but I can't use the front axle as it had no front brakes and is not a strong enough axle in my limited opinion. My options as I see it are to:
1. Use an axle from a chevy , ford or international truck to mount to the leaf spring but it presents problems with lowering the car enough to satisfy me or...
2. Use a ford front axle from a model A or later ford with the transverse spring and redo the crossmember which would require either
A.... notching the frame for the spring travel..or
B ....cutting the frame off and going with a suicide front set up.

I like the idea of using the existing leaf springs but am not sure how to go about it properly....I thought about mounting the axle from a truck to the top of the leaf spring but it also gives me limited wheel travel then and brings the bottom of the springs and U bolts very close to the ground.
One thought I have is to buy a dropped tube axle from Speedway and then I can weld spring perches onto it for mounting to the existing leaf springs...however I am not sure how I could get the 6-7 degree angle on it unless I just tack it and get the rest of the build done and then readjust my perches if necessary.
My goal is to do as simple of a build as possible.
I am also planning on using the rear springs as well with a newer rear end but similar to the existing setup. My goal is to lower the frame 2-3 inches, channel the body the depth of the frame which is close to 6 inches and then see what is left for headroom for a chop.

I'll stop rambling and let you or any of the others here with experience respond...thanks in advance.

 

sounds like you wana do a radical build with lowering, channeling, and choppin! Id study this thread fowards and backwards and consrtuct a new frame! and your probably better off usin an A axle

 

When you say standard do you mean a 28-31 frame? can you explain why this wont work?

 

Yes, I do mean a 28-31 frame. Why won't it work---Well, firstly, a model A frame turns down by about 1 3/4" to 2" between the front crossmember and the end of the frame horns. If you put the suicide crossmember at the end of the frame horns, you will actually be raising the frame up by that amount---exactly the opposite of what you are trying to do. Secondly---the frame gets much smaller in vertical height out at the ends of the frame horns---which means that if you put the suicide crossmember out there, it can only be about 2" diameter, which is too weak for most V8 engine packages.
If you remove the stock front crossmember and cut the frame off at the center of the crossmember, then yes, you can do it to a stock model A frame, because the frame is deeper there, allowing a 3" diameter crossmember which would be large enough in diameter to support most any V8.

 

Very nice
Thanks Brian!

 

what an awsome, informative, helpfull thread you have.

i plan on doing my first build with most of the info i gathered from here.

thank you for your time, answering other ppl questions and so on.

terry

 

Great information.

 

A friend of mine in another Ontario city recently finished a build on a model A Tudor sedan. He had used a lot of the information from my chassis building thread on the HAMB, and we had a few telephone conversations over the couple of years his car was going together. He finished the car this spring, and called me to drive down and "Have a look at it." I drove down to Sonya, Ontario and had a look. The car has potential to be a great rod. I'm not a fan of the "Rat-rod" look, but rusty bodies can eventually be straightened and painted. Its the chassis that makes the car. If your chassis is crap, then no amount of shiny paint and bondo is going to make it a nice car. Everything looked really good---EXCEPT--The steering shaft, between the firewall and the Vega style steering box had two Borgeson type universals in it, and one rag joint. The shafts on either side of the rag joint were misaligned by about 15 to 20 degrees, and there was no support bearing on the intermediate section of shaft. PAY HEED--Rag joints were never intended to be used as a universal joint between two misaligned shafts. They were factory installed as a vibration isolation device, and they were never intended for more than 2 or 3 degrees of shaft misalignment. They can and will fail. I know---I was in a 61 Pontiac convertible one time when the car suddenly took off with a mind of its own, and drove through a corn field. The stock rag joint had ripped in half---Luckily, said car was only travelling at about 20 MPH at the time, and no-one was killed. I have seen steering rag joints used on a number of hotrods over my 64 years. This does not make it right, and it does not make it safe. And even if you're not killed, where do you think the liability will fall when your car swerves and takes out a pedestrian or another driver. The insurance companies and the lawyers will follow the financial liability upstream untill they find out who built that steering system, and then your ass will be grass!!! Be safe guys. Use proper universal joints in your steering shafts, and always use a support bearing on the intermediate shaft if you use more than two universal joints in a system. I'm not the Ralph Nader of hotrod world, but Damn, I don't want you dead either!!!----Brian

 

Brian speaks the truth about rag joints. Saw a broken one last week.

 

Morrisman---I'm not going to get into a shit slinging match on my own thread, but you use that word "invariably" very loosely. I have seen many of them on early builds without the safety feature.----Brian

 

we all appreciate your self control but, did you read his second sentence?

 

It seems to me that I have seen them from the factory without that safety feature. But---Hey, I've been friggin with old cars for 45 years. I don't remember everything I ever seen 100%. I could be mistaken.

 

bottom line is (exactly what you are saying Brian) if you use a rag joint use it only for what it is intended for, shock isolation not shaft misalignment correction

and because they can fail the safety pin, as Morrisman shows, should be in it's correct designed location

 

If I remember GM had a recall on the rag joint because they didn't have the safety pin from the factory. I do remember seeing a bolted on safety device being put in the system instead of a pin. All of the ones that I have seen were from the early-mid 60's.

 

Thanks for the info.....very useful stuff

 

very helpful thread. Thanks for the time to share all of this information.