Tech Request - 1/4 Elliptic Springs

1/4 elliptic springs seem simple enough. Has anyone made any? Anyone out there looking for a tech post idea - here it is.

About the only drawback I can imagine might be the hardness of the spring steel when it came time to cut the leaves and drill them.

Thanks, JH

 

Cutting them is easy. I used my whizzer(cut-off wheel) and sliced right through them. Drilling the locating hole is what sucks. Use real slow speed, plenty of oil, and keep stepping up drill bit sizes.
I made my 1/4 elliptics from a 53 F100 front spring. I used 3 leaves, made the whole pack 17" long. I considered trailer springs, but they were too thick. I put a lot of miles on my car last year, and the front suspension rode very nice.

Karl

 

Got any pics of how you mounted them on the frame?

JH

 

Do a search - someone ran a 1/4 elliptic setup about a year ago here - can't remember particulars, but a search may dig it up...

 

I used my plasma cutter to slice my 40 springs in half....piece O cake!
Drilling was not so bad...just used a drill press and started small...maybe 1/8 " for a pilot hole...then stepped up to a little bigger...plenty of lube...oh yea...I drilled the whole stack at one time...bolted the springs together before I cut them and drilled holes on either side of the center...kept them all aligned that way.
And no the heat from the plasma cutter won't hurt the temper ...at least not the way I set up my rear suspension...sandwiched the cut ends between two big plates of steel and ran a bolt through them with the eyes of the spring going to a bracket on the rearend. Then triangulated 4 bars from the pumpkin to the frame to keep it all straight

 

buckethead

used dodge caravan rear springs to make his 1/4 elliptic's for his modified and they worked out great.

 

Here's a couple pics of my set-up. The pictures are rather confusing. Basically I built a channel on the bottom of the 2x3 frame that the springs sits into, and the spring gets sandwiched in between the channel and a piece of 1/4" steel. Ignore the rusty bolts .






Hope this helps,
Nobux

 

Jim, I've pondered this myself. I think I'm gonna use 1/4 elliptics on my '27rpu. I'm plannin on mounting mine toward the top of the frame and then using a bar on the bottom. Kinda like a four bar setup, but the spring would actually serve as the upper bar. Do a search on my "unusual front suspension" post a while back. There's some good pics.

Count

 

On the spring pictured above, and it sounds like on the one Brewsir describes, the main leaf is attached at the shackle and has a bolt through the rear at the mount. All the other leaves only have the bolt through the rear.

What keep these leaves from "fanning out". Seems like you would need two bolts a few inches apart at the rear mounting position to keep them all lined up.

JH

 

What keep these leaves from "fanning out". Seems like you would need two bolts a few inches apart at the rear mounting position to keep them all lined up.

JH[/QUOTE]
On mine I used 4 bolts to sandwich the leaves...plus the center bolt through them all....the 4 bolts will keep them from fanning out.

 

Just good ol' clamping force.

Easy enough.

Thanks, JH

 

The "pocket" on the frame that holds the rear of the spring is about 6" long. So, 6" of a 16" spring is held in perfect alignment. Over a 1/3 of the spring. I haven't had a problem. I drive down gravel, bumpy roads and nothing has happened yet.

 

You can't use the springs as a suspension locating component. As the spring is flexed, it lengthens. this would change your pinion angle a lot and right now. This is the voice of experience talking.

 

[
About the only drawback I can imagine might be the hardness of the spring steel when it came time to cut the leaves and drill them.

Thanks, JH[/QUOTE]

Drilled several leaves with a carbide masonry bit. Just sharpened it like a regular drill bit and used some slippery cutting lube. Slow speed and steady feed.

 

I think most spring shops punch the holes in the leaves.

 

the guys at the ironworker shop said the springs can shatter from punching the holes.we used trailer springs and drilling them was a f-ing nightmare.we planted weld bungs through the frame and bolted the springs to the frame with 2 grade 8 bolts per spring pack.

 

I would like to see pictures of this. I had the same basic idea for my phantom rpu, although I haven't committed to it yet.

 

I have a Zipper Lakester with 1/4 elliptics front and rear. Zip has the springs manufactured to his specs. They're bolted to the frame with 2 grade 8 bolts on each spring. His springs are set up to handle a 350/350 setup. My car has a "banger" with a '39 trans, so we took one leaf on each corner. The handling is better than a car with "buggy" spring suspension, especially with the friction shocks. I think his site is www.zippermotors.com.

 

ZZFord says it won't work...as a locating component...guess I will have to get it on the road and find out for myself...i'm just stupid like that sometimes. I can't get a pic due to a broken camera,but I am getting it back in my garage in a month or so ...want to drive to Billetproof this year!

 

You will be fine Brewsir, zzford knows not of what he speaks. The McMullen 32 had 1/4 elliptics as locating arms and Tom drove it hard. Speedways 32 Lowboy uses the same method as do hundreds of other cars through out history.

 

What I did.

 

Here are some I've saved.

 

I wasn't gonna come out and call BS until I tried it ...but from what I see it looks like it will be fine The problem is when you have leafs that have a lot of arch in them,or that just are not set up properly...then it seems the length of the springs would change drastically....or maybe if there isn't enough springs in the pack...then you could get spring wrap.
Still...any incentive I can get to get this thing on the road works for me!

 

I didn,t say you can't use it, I said it will change the pinion angle as the suspension works. It is poor engineering.

 

Harry Miller used them on the front drive Indy cars, and every Bugatti built used 1/4's on the rear.

 

Seems to me that if the rear goes up and down then the pinion angle to the driveshaft changes regardless of how it's sprung, 1/4 eliptics, leafs, 3 bar, 4 bar ladder bar or whatever. It just needs to be within the specs the u-joints call for.

 

How about we rephrase what you said. If the pinion angle changes drasticly when the suspension works YOU engineered it poorly. If the installation is properly set up you can certainly use the spring as a locating member.
zz, how about posting some pictures of your suicide setup and we'll give it our best verbal (written) citique?


Frank

 

this is a great thread and has given me some pondering on my own 34-35 with the parrallel front springs...in the one pic with the 1/4 elips as upper and lower control type arms...do you guys think that I could cut my front springs in half and run them in a similar form....just seems too easy and makes you wonder about pinion angles ...what do you guys think about side to side movement...do you think that you would still need hairpins, bones or what ever else thats keeps side shift to a minimum...just curious..might have to go to work and start cutting and drilling...joe

 

OK so if I use my springs as a locating member and triangulate the upper bars off of the pumpkin,to the frame. What is the proper placement of the bars to minimize pinion angle changes?? I have mine tacked in so they are parrallel to the springs i.e. the rod ends are the same height from the spring eyes as the other ends are from the mounting points of the springs. My bars are adjustable so I can correct pinion angle...I am thinking put weight in the car (as in my fat ass) and adjust the pinion angle so that it is down a couple of degrees. That way under power it should be about right. I will post pics when I get some.

 

Upper trailing arms are usually lower on the front.