Building my own "caltrac" type bars

[BigBlockRanger]

I posted some of this in my Ranger project thread, but thought it might get a little better exposure in the tech section.

Fired up the plasma cutter this evening and started making plates for a set of "BBR-tracs". I decided I could make a set far cheaper than caltracs or slide-a-links.  I'll detail what I did in the event somebody wants to make some too.

I eyeballed many many pics of caltracs, slide-a-links and other people's home built units before coming up with a bellcrank size and shape.  I ended up with 4" between the holes. Normally the holes are 90 degrees to each other. Since the Ranger uses an on-center eye spring (think lollipop shape) instead of an offset eye (think the letter "P"), the holes should be over 90 degrees.  So I came up with a plan and drew them in AutoCAD.  I have these in a pdf that prints out 1:1 on an 11x17 sheet.  www.bigblockranger.com/bellcrank.pdf 

1. I printed them out and used them to make a stencil.

2. I laid it over the 3/16" plate steel and shot it with white paint.

3. I traced around them with a sharpie to better define the edges using a cardboard cutout as a template.



4. I clamped them all together and evened them up with a 4" grinder and a double cut file.



5. I overlaid a paper template to locate the holes and center punched them.

6. I drilled all the holes with the drill press while they were all clamped together.



The rod and pivot holes are not drilled to final size just yet.  I wanted to wait so that I get the hole sizes right.

The spring plate on the Ranger is not flat so I decided to add a flat section. So I plasma'd 2 - 5.25" x 2.5" pieces.



Then I cut out 2 chunks of 2' square tube.



Then I drilled a hole for the bolt and plasma'd one side out and welded them to the flat pieces.



This is how it fits in.



This is the final product. All hail the king of caterpillar welding.




2 pieces of 1" x 24" DOM pre-threaded (3/4"-16) tubing was ordered from www.suicidedoors.com

Tubing came in and it is only threaded on one end... pooooop.  Luckily, one of the guys I work with happens to have a 3/4"-16 tap.  It is not LH thread, but that's ok.  It will just make making bar adjustments a little more involved.  At least with RH-RH, if the jam nuts vibrate loose, the bar can not change length.




Running total update:

3/16" plate = $8.00
steel tubing = $36.00 (1" x 24" DOM internally threaded 3/4"-16)
grade 8 bolts = $22.00 (2)9/16 x 4, (2)5/8 x 3, (2)5/8 x 4, (2)3/8 x 3.5 and nylock nuts.)

Subtotal = $66.00

All I need now are the rod ends, and 2 pieces of 3/8" ID tubing cut to 3" (which I have) and I will almost be ready to bolt them in.

[Beagle]

order the tap... I guess Irwin is now Chinese, but here anyway:

http://www.irwin.com/irwin/consumer/jhtml/detail.jhtml?prodId=IrwinProd100437

Nice work!

[BigBlockRanger]

I can order a LH 3/4"-16 tap from www.WTtool.com for $21 shipped, but geez, when would I ever need it again? 

[milner351]

Very nice work - hopefully I'll have the skill and patience to duplicate this set up on my ranger, once I can finally get to it!

[CDMBill]

Having worked with both and come up with a bit of a blend of parts that seem to work well. First you'll want a gusset to support that square wall tube as it bend backward under load. The mount plate for the leaf spring pad could use some additional stiffening. The CE piece is .25" plate in a broad flat 'u' shape with stiffening plates on the side.

Second I didn't see what you were going to do at the front spring eye. Both the CE Slide-a-link and Cal-Trac products use an interference fit, solid aluminum front bushing. They have a steel sleeve that goes through the bushing for the front mount bolt to go through and set the clearance for the end plates so when everything is tightened up there is no bind. The bars don't work if the side plates or leaf itself binds in the front mount. For a true street strip car I think the Global West Del-alum bushing would be ideal but I've gone 10,000 miles on my set up with the sleeve and bushing with no issues yet. I used synthetic grease during assembly.

The sleeve is 1" OD on the Cal Tracs. .75" on the CE. Both seem to be finish machined, not just some chunk of tubing. I originally had a set of multileaf springs with an extra front half-leaf for "traction". They had a mid-eye main leaf as you describe 'lollipop'. They didn't work at all, waaaay to stiff. I have the Cal-trac mono-leafs now which are awesome. You want just enough spring to get the ride height where you need it. With thin leafs you'll want to clamp them to keep the front half rigid.

The side plates have a large OD tube on top that presses down against the spring under load. The CE uses a machined step on that rear tube to keep the plates apart at the same distance as the spring eye sleeve does in front. I added two bolts with heads cut off that I rosette welded to the inner plate to keep clearance to the frame rail under braking when the plate rotates back (clockwise looking at it from the side. These bolts stiffen the assembly above the mounting point of the bar.

The front solid rod end and the rear hiem-end use a .75" bore and shank size. I wouldn't go smaller.

I originally bought Slide-a-links because I thought that the polyurethane piece that sit sin the middle of the sliding tubes would be better for the street. The Cal trac is a solid tube of course. I still think so but lots of people drive on regular Cal-Tracs with no reported issues. I also try to do a bit corner turning and I wanted to keep the bar out of the equation for braking and cornering.

[BigBlockRanger]

Thanks for the input Bill! I was hoping somebody would chime in with suggestions.

I do have a solid aluminum bushing setup for the spring eye.  I don't think the 5/8" bore rod ends (3/4" shank) will be a real problem as the actual spring bolt is only 1/2".  BUT, I might go with 3/4-3/4 rod ends because they are available locally and the 3/4-5/8 is not.

I have flipped flopped about the brace behind the square tube. My original intent was to do it, then I got to thinking that it is only 2.5" from hole center to the base of the tubing....  I am leaning towards adding it just for peace of mind.  The spring plate and the piece I added are both 1/4" plate.  I may ultimately end up just making a new spring plate.

[BigBlockRanger]

Running total update:

3/16" plate = $8.00
steel tubing = $36.00 (1" x 24" DOM internally threaded 3/4"-16)
grade 8 bolts = $22.00 (2)9/16 x 4, (2)5/8 x 3, (2)5/8 x 4, (2)3/8 x 3.5 and nylock nuts.)
rod ends = $76.00 (4) 3/4" shank, 5/8" hole, National Rod End brand

Total = $142.00

[Caveman]

If you really want some left-hand thread to make adjustments easier, you could just order a bung.  There are a few off-road fab sites and shops that make 'em with left hand threads.  All you have to do is weld it on the end of your DOM tube, and the rod-end will thread right in.

[BigBlockRanger]

I kinda avoided using bungs because I doubted my ability to weld them all cleanly w/o jacking at least one up. 

This is what mine look like today.  I added a triangular brace to the back of the square tube for additional strength. I also tapped the other ends of the tubes today. Piece o cake.  They sure look looooong, but the springs on the Ranger are looooong.



Rod ends I used:

[Caveman]

How does the length affect launch performance?

And what is the optimum length?  Even with the spring eye?  or longer than the spring eye?  if so, how much longer?

Hate to pester ya, but I'm looking at doing something similar on my old hulk. 

[BigBlockRanger]

The stuff I have read and looked at shows the eye to eye rod length being the same as the axle centerline to spring eye length.  In my case, this distance is 26".

[Rebeldryver]

Very nice work.

[outlaw57]

look good, will be making a pair for my 57, but i've got a cnc plasma at my disposal

[BigBlockRanger]

There is a local shop that does cnc plasma work at a very reasonable price. I almost had them cut them, but decided to give it a whack myself.


I think I just found a good source for steel pins, either for a spring eye or for the little bolt that goes over the spring.....

piston pins.


A Dodge 318 piston pin has a ~11/16" hole, a .98" OD and is 3" wide. And some Ford 2.9L pins are 2.75" with a 9/16" hole and a 7/8" OD.  Others might work better, but these were the only two I had in the shop to look at.

I think I might use a 2.9L pin over the spring. They might need a little trimming to narrow them a smooch, but that's no prob.

[Ricks57]

Hi,
Here is a web page with some simple directions that may help.

http://www.hotrodsandhemis.com/Traction.html

Rick