Projects '34 front frame C notch question...

I have the frame upside down to finish the welding and did a C notch at the rear (I may have flattened that '40 crossmember a wee bit too much), and I think I ought to notch the front as well. I've had the car assembled, 283/350, Walker Radiator, 4" drop axle and reversed eye Super Slide spring, but the front is still a couple inches higher than I'd like. I want to drop it a bit more, and think the time to notch the frame is now, before I paint it and put the car back together. I have a piece of rectangular tubing I can use for the notch, can I get a way with just that, I thought I'd just cut a section as deep as the frame width, cut one side off the tube, and weld it in the rail. About an inch? It's fairly heavy wall tube, thicker than the American Stamping rails and boxing plate, looks like it'd work.
On the same topic, I was thinking of removing a leaf from the spring, or perhaps flattening the spring a bit for the lowering. I also have an original spring, which I thought I could reverse the eyes, and flatten a bit. It seemed pretty "stiff" with the little Chevy installed. On the right track?

 

Oops, wrong photo. This is t he rear, and my real question is, should I plate the front rail as I did the back? It'll be inside the crossmember, and the tubing I'd like to use is heavier than the frame rails...

 

Does your glass body drop over the rails in back like a stocker does? Those plates would be in the way on a stock body. I put plates on the inside before boxing.

 

I don't think so, there's a little clearance between the frame and body. It's a bit over 1/8" thick plate is all.

 

The chunk of tubing for C notch...

 

I did that years ago...well i think i did... memory tricks me into thinking that i put a section of the "notch" parrallel to the flat surface of the spring a short way up into the xmember, then added a small bumper stop to that surface...in case my cyfering wasn't top shelf, all might still be forgiven...

 

Looks like you won't have much of a notch on the front with that shock mount there. But some is better than none if you need it. Could even make the inner edge of the notch higher than the outer skin, since the spring has curve to it.

 

The shock mount can move.

 

I think you will be fine with your plan. Nothing mounts to the frame in front of the notch, at least not much weight. The real load in that area is in the cross member that spans the notch and with the frame stock size right at the rear side of notch I don't see you hurting much.

 

I thought so, I've seen C- notched fronts, thought I may as well while I'm doing the frame, then just read a post here about a frame cracking right behind the crossmember. Looked to me like the heavy wall tubing would be stronger than the original frame, along with the crossmember itself.

 

Cutting. Monoleaf spring on the way. Merry Christmas to me!

 

looks great

 

Check with So-Cal Az, about Mono leaf,
he has some broken ones upstairs, for show and tell

 

I've quit selling the D----- mono leaf springs as I've had several break. I'm replacing them with a Posie dual flex spring.

 

there ya go.....

 

Mono leaf on the way? Some people don't listen. Good luck.

 

Helpful comment. ^^^ FYI, the three posts advising against were all after I'd already purchased the spring, and said so. I did search for and read the thread about mono-leaf springs. Not like I ignored comment or advice, I made a choice that'll work for me.

 

I only see post 11 mentioning mono leaf when you said it was on its' way. Previously you said you had a stock and a Posie. How many springs do you need


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As many as it takes to get it to set right. ;-) I have both stock and reversed eye Super Slide, (the stock one is pictured laying in the crossmember, above) that came with the project, and it's up in front more than I want it. So down it shall go.

 

This is with the reversed eye, mocked up a couple weeks ago.

 

The front crossmember has a lot of dip to it.
Flatten that too, that will get you down in front , at least that's what's holding it up.

 

I think I'd run into all sorts of fitment problems with radiator, engine, grill shell, hood alignment, that'd make a flatter, thinner spring look like winner-winner, chicken dinner. ;-)

 

Its the lower hose outlet on a factory style 33/34 radiator that might cause trouble.

 

Yup. I have a Walker radiator, and while the center of the crossmember could come up, it'd put the outlet smack in the way. My crank pulley is just behind, so I guess that wouldn't be an issue, but sure looks like the most practical way out (or down) is the mono leaf with the spring on top of the spacer blocks. I've got a mono leaf already in the rear, so I'm already committed to having half the experts here tell me I'm wrong. ;-)

 

Sure it will work, but a mono spring comes with well founded concerns and plenty of reports of them failing. Plenty have used them forever without issue and plenty have had them break. Lots of "opinions" on ride quality as well. I think that's what the experts are concerned about. Plus you asked if you were on the right track


When I look at this picture,
-
Yes she's riding high-
It looks like the spring is too long with too much arch, at least compared to all he others I've set up. That's also why it seems stiff. Depending on the finished weight there's only about 2-1/2" to 3-1/2 inches between the top of the axle and bottom of a reversed spring measured at the center. Here's a shitty pic that I had crawl over and lit with a flash light. This measures out at 2-3/4 from the bottom of the crossmember to the top of the axle. If I had to guess it looks like yours would measure closer to 6" here maybe more. Remember this is a revere

It doesn't matter which crossmember or axle either as long as it's spring on top. That relationship remains the same.


On your frame I see a 33/34 sized dip in the front crossmember and the front C notch in 33-34 rails. In real life dynamics on a hard hit the spring will need compress into a reverse arch to pass thru the or bend the axle out of the way before it enters the space of the front C notch.

Here's another shitty pic lol
But it's 34 rails with a model A crossmember. The notch is 1-1/2" deep and there is 3" clearance.

I grabbed this visual aid so I wouldn't have to draw it

So installed with weight my measures are B 29-3/4 and A 1-1/4.
Shackles are at 46* and perch eyes are at 32". The eyes are reversed but the measures are at center to center. That is an after market axle so the exact dimensions will differ for a stock axle but the plotted arch should be real close.

Hope this helps get your ride height where you want it

 

Thanks. Mine is indeed a '33-34 crossmember. The axle is 36 1/2" C-C on the perch bolt holes (roughly, as I guesstimated where the center of the hole was on the boss, but I'm within 1/8"), so if I deduct 5" for the shackles, that gives me a '31" eye to eye on the spring, which is what I have. I had to compress that spring to get it in the shackles, I don't see how a 29" spring would work. The non reversed eye spring I have is the same width, and I originally thought I'd de-arch it, but, that makes it longer, which, in my inexperienced POV, I thought wouldn't work. Thanks for chiming in, I'm new to this ancient Ford stuff, having built mostly wiggle-y front fat fendered cars and '60's customs.

 

Remember my spring and axle are aftermarket and narrow and I said would be smaller than yours. You can still get the idea of amount of arch though.
The eye to eye measurements without the arch height included means nothing. You can have 31" eye to eye with 10 mile arch height or 10" arch or 1" arch. See how that arch changes the ride height. That's why De arching a spring makes the eye to eye longer.

I see this I'm my head as a very quick and simple thought, but it takes volumes to explain it.
These transverse springs are mounted in tension. That preloaded tension effects the available spring rate because NO leaf spring is measured with this preloaded tension. They are measured free and loose. A measured load is applied and deflection is measured, that's how they do it. Nobody stretches a spring first then measures the rate but that's how a ford transverse spring works.

 

This one rides nice and came out ride height just where I wanted it to.



This one was about 3" between top of axle and bottom of spring

 

I totally get it, but still don't get why the parts I have end up with ride height they yielded. To illustrate:
Both springs have the same unloaded length and arch, aside from the reversed eye of the new one.