Z frame chassis

[Ebaby35]

Ok this is my first ever build if any kind and would like to build my own chassis. I bought plans from hughsratrods for a single z frame. In the plans it has the width at 20" seems narrow for me but I dont know anything. This will be for my 38' dodge pu ratrod

 

[bruno]

If it helps, my inside frame rails at the front are 20". At the cowl it starts widening and ends up at 37" at the rear of the cab. From there it is 37" all the way to the rear. The frame is 2X4 by 3/16 tubing.

 

[williej45]

The cowls on most of our cars are quite narrow, hence the 20" width. This also makes engine mounts easy. Once you are past the cowl, the width can increase, but why go to the effort? The rear suspension is often outboard of the rear frame rails.
By the time you add 10" per side for coil spring perches/ arms/ shocks you are at around 40". A 1938 truck bed isn't much wider than that. Negative offset on a set of reasonably wide rear wheels will close up any gaps between the tires and the bed sides.
I have built several single Z frames this way, and they have run down the road just fine. I don't suggest autocross in one, but for a simple cruiser, they work well.
If for some reason you need it wider at the rear, you could make the upper "deck" a subframe of sorts at the width you need.
Just be sure that the welds are up to the task. it's not just your life that depends on them!

 

[bruno]

Before you go welding any thing up mock up the frame using 2X4s. You don't want to end up with problems like firewall to cowl clearance, radiator to fan and other things. If you are going to run a spring behind or spring over front end that will make a difference also. I had all of my suspension parts, engine, transmission, radiator and rear end and then made a wood frame, worked out great when i drew up my plans.

 

[King Herald]

Before you go welding any thing up mock up the frame using 2X4s. You don't want to end up with problems like firewall to cowl clearance, radiator to fan and other things....

This is a good idea. Time consuming initially, but it doesn’t have to be a work of art and will give a damn good idea the general layout of the whole car.

I once built a Zeed frame, to ride really low, and halfway through the build had to cut it in half and change it, as the exhausts needed to go right through the frame rail, the Zee was so big in front. It was my first frame build.......[S

 

[kenny c]

All very good suggestions. When I built mine I did the same as Bruno. Another suggestion is only weld the rails together . Just tack weld in all other parts like cross members. motor mounts. cab mounts and brackets. This allows for removal and adjustments. I made a few mistakes when I built mine and had to spend a lot of time cutting things out.

 

[Tripper]

Donsrods posted his Z'd frame build on another forum & I followed his lead. I build a wooden 2x4 version under my car & then converted into steel (2x3). Mine is 20" in the front (my radiator is 19" wide) & 27" in the rear. If you want to follow along... here's where the frame building starts on my build thread...

http://www.ratrodsrule.com/forum/showthread.php?t=25149&page=13

BoB

 

[kenny c]

You can also check out my frame mock up by clicking on my build thread at the bottom of this post in the signature " Tetanus Tornado"

 

[Old Iron]

[cl
[P[P[P

 

[Ebaby35]

When people do a "z" in the rear I see some at like a 45 and some at a 90 degree is there any reason to do one over the other?

 

[kenny c]

If you are using parallel leaf springs in the rear a 90 degree setup may work better. If using a triangulated 4 link it may also help if you need a cross member to attach the upper links to. I like the 45 degree setup for looks and I feel it is a little stronger because of the longer joint but probably doesn't make much difference.