59 Catalina

[kb426]

This will be interesting to watch. I had thought about doing this before but not enough to have a real plan.

[idrivejunk]

"This" being 59 Cat on 17 Morrison :?:

[kb426]

No. Replacing a unibody floor with a full chassis. That's pretty common anymore so I've watched several build threads and there seems to be 2 common ways. 1 is to remove all the floor to the rocker panels and the other is to splice in. But most have straight frame rails, not lots of angles. The angles make it more interesting to watch.

[sirstude]

This is still kind of an "X" style frame like was original instead of a perimeter frame, correct?

[idrivejunk]

KB I should have put a smiley on my post too.  I am pumped about this job. This is a full size B body that had an X or hourglass type frame. The headers hop a stock frame and run outside the rails. This frame has room for pipes along the driveshaft. Rails are three feet apart up front. I just about have it down all the way now. The desired rocker height at rest is 5 3/4".

[416Ford]

Great work Matt. Keep it up as long as you enjoy it. Then hopefully you can just manage others to do as you tell them.

Or Write a book.

[idrivejunk]

That yesterday was a mighty tough afternoon I must say. That hurt!

Just a couple hours on it today got it the rest of the way down. For a scale reference, wheelbase is 122".

Here is a pic for proof:



The tape measure here indicates ride height of the rocker when it's all said and done, and the bottom of the frame and body do end up about even.



Top of the rails, once mounts and bushings are in place, are intended to be juuuust below the level of the stock pans at the front footwells. The angle iron under the firewall mounts holds it a little low, and the wood blocks out back are a little thick. My work thus far was just to get enough clearance to sink the body far enough down to nail down exact placement. So far so good!

Visit my blog to see more pictures at:

http://chevroldsmobuiac.blogspot.com/2017/09/catalina-repairs-body-mounting.html?m=1

[idrivejunk]

Guys let me run my body mounting logic past you,OK?

1- Level frame
2- Level body
3- Center body
4- Establish fore/aft body position referencing wheelbase to front body mount, to match original dimension
5- Lower rear of body onto mount bushings
6- Lower front of body until rockers are level again, then support body with temporary braces attached to frame.
7- Fit drivetrain and tires / wheels
8- Fit bolt on panels
9- Build floors and bracing and attach body mount pads to frame
10- Rust patching

Sound right?

I am at step 6 and the whole thing is on a dolly now. I am told it can be rolling inside of one day so I think I will get the trunk lid skin tacked to the shell and remove it to finish that up while it gets some wheels under it. And I'll request front and trunk pans be ordered, along with a couple kinds of square tubing I want to use for frame mount pads and floor braces. This is great fun and hard work!

[kb426]

I was doing real good until 10.

[idrivejunk]

It is everywhere. I could build an argument that it's as bad as the Biscayne was. Hey, Bill what would you think if you saw round tube such as exhaust pipe used to make floor braces? The frame has round tube crossbars at front and over the axle.

[kb426]

Matt, if it was a race car and we were fighting weight, I'd be ok. On a street car knowing that there is alot of 18 gauge tubing out there, I wouldn't think it was the best idea. At 14 gauge I wouldn't have thought much about it. Now with that being said, I realize that an engineer with a slide rule, calculator or a computer is much more adept at stress analysis  that my cad or chalk on the floor so I'll go be quiet in the corner.

[idrivejunk]

Don't worry, a barf bag will drop down above your seat as we approach step ten.

Tubing is just a thought that crossed my mind when imagining how to be simple and effective. 16 ga would do, and it popped in my head that a row of plug welds atop round supports could be corrosion proofed so much better than with a boxed brace. Can anyone offer input as to potentially using thin wall square tubing to make floor braces? My thought is I could shape them quicker with pie cuts and stuff, and go all the way out to the inner rockers rather than trying to blend in with whats left of the originals. Fanciness level could drive the price into orbit here and nobody wants that but we all want it to look like it sort of belongs and of course the fabbed parts have to be strong enough for the job.

[kb426]

A couple of thoughts: round tubing is the same strength in all directions, square or rectangle isn't. When you mix round and square, it doesn't always look correct. Most will say that nobody sees what's underneath but we all know that lots of people look and care. When the cost factor is the strongest comparator versus ascetics or optimum strength, I think the decision has already been made.  In general, same wall thickness on either will be comparable in strength.

[idrivejunk]

I am forming options to present to the powers that be, really. If they don't make the choice, I will. Before I even sleep on it I know my inclination is leaning toward square tube, 2.5 or 3", not sure what is avalable. In my mind, the rigidity is plenty either way and the floor is not a crush zone per se, although with the hourglass frame that is less true than with ladder type. If a wreck gets into the pan area you may already be dead. If it flips over I want that body nailed to the frame, and a greater number of round supports would be needed in that event. Building on to the existing support remains sounds like a lot of work that would look hokey anyway. In any case, its getting a bazillion body mounts. As far as the uncut unwelded structural integrity of tubing or pipe goes, all that will be lost to notching and clearancing this or that plus the row of plug welds. No need for the supports to absorb impact like a cage. Speed in shaping the pieces is more of a concern than whether they would be strong enough. It could be strong enough either way if thought out well. The car is probably going to weigh more than stock and it certainly is a show car.

[idrivejunk]

I sure appreciate your contribution to my mental process, never be shy.