Starting on body floor, firewall and mounting. Any tips?

[RatchetRob]

Going to start on body this weekend. I have already cut a cardboard template of the floor. My issues is that trans and drive shaft both protrude through floor. How to split the floor into to pieces and then strengthen them? One person suggested integrating the seat design to span the width of the interior and add support to the back. I want to glass in the trans tunnel and was thinking of using a metal "skeleton" around trans tunnel and covering with duck tape like ex-junk did. Also seen 8" pvc pipe cut in half as a template for driveshaft cover. I am thinking of covering drive shaft with sheet metal though to keep any parts at bay. Not sure on making trans cover removable Of course there would need to be access to shifter linkage.. My thinking is the trans is so easily removed from bottom of car to worry about that. I think glassing in the tunnel and trans cover would help with strength.
As for mounting I am thinking of using tabs welded to frame. Four of them with 3/8 inch bolts. Some type of material in between and maybe glassing steel plates into floor for the bolts.
Any suggestions or tips and ideas appreciated. Photo's are a big help as well.

PS I am not channeling body over frame so floor will sit flush with lip of body and top of frame. I am thinking of using a felt pad on top of frame rail.

 

[Hotrod46]

I used temporary wood ribs covered in aluminum roof flashing as a form for my trans tunnel, but Junk's method may be easier. The flashing is easily cut with good shears and fiberglass doesn't stick to it well, so it's easy to remove the form.

If you are concerned about keeping driveline parts out of the interior, build a driveshaft safety loop (or 2) on the frame. I put 2 on mine. Might not ever need it, but if a driveshaft comes loose for any reason, you'll be glad you had it. Sheet metal will not reliably stop an errant driveshaft unless it's pretty thick sheet.

Not really part of your question, but take the body outside and wash it well several times before doing any sanding on it. Most bodies still have mold release agent residue on them. If you sand on the body, you will drive this RA into the surface and cause paint issues, like fish eyes.

Mike

 

[2old2fast]

Trouble w/felt is it absorbs moisture , not good....check around , co.'s change out light conveyer belts frequently , you should be able to find something about 1/4" thick.... Choppin czech [sp] has apretty good handle on what it takes vto glass in your tunnel [matte/cloth weights/layers] by all means incorporate solid frame mounted driveshaft loops..
dave

 

[2old2fast]

Trouble w/felt is it absorbs moisture , not good....check around , co.'s change out light conveyer belts frequently , you should be able to find something about 1/4" thick.... Choppin czech [sp] has apretty good handle on what it takes vto glass in your tunnel [matte/cloth weights/layers] by all means incorporate solid frame mounted driveshaft loops..
dave

 

[Zandoz]

It sounds like your configuration is similar to what mine will be someday. The biggest difference being that I need both the transmission cover and the driveshaft tunnel to be easily removable...I need maintenance access to both the transmission and U-joints from above, because my mobility issues make working from below impossible. I'm looking forward to the advice you get here.

I've pretty well worked out my plan for floor support for the rear halves of the floor. Between the frame rails, the transmission and driveshaft crossmembers, with 2x1-1/2x1/4" aluminum angle spanning between them for the length of the driveshaft tunnel. Both legs of the angle will have regularly spaced nutserts...the floor bolting down to the shorter horizontal leg of the angle, and an aluminum or steel driveshaft tunnel bolting to the longer vertical leg of the angle extending above the floor. For outboard of the frame rails, behind the door openings, the rear control arm brackets will do double duty as large floor support platforms.

For the front halves of the floors, outboard of the frame rails, the platforms for mounting the dash and steering column hoop will do double duty as floor support.

Supporting the front halves of the floors, inboard of the frame rails around the irregular shapes of the transmission, is where I'm stumped. Beside the irregular shape, it must allow the transmission cover (also a puzzle) to be removeable.

<shrug>

 

[RatchetRob]

Yes driveshaft loops are gong in. Trust me! Just meant as a added measure of safety I was thinking of making drive shaft tunnel out of steel. The flanges at bottom of tunnel would bolt to floor thereby supporting the two halves.

 

[2old2fast]

Front of floor will be supported by firewall , rear by body , center can be supported by seat riser..... my seat riser is attached to a tube steel truss.....
dave

 

[Zandoz]

Yes driveshaft loops are gong in. Trust me! Just meant as a added measure of safety I was thinking of making drive shaft tunnel out of steel. The flanges at bottom of tunnel would bolt to floor thereby supporting the two halves.

The reason I'm planning on aluminum angle to fasten the driveshaft tunnel to the floor, instead of bending flanges on the tunnel itself, is that it's 2 less things I'd have to pay someone else to do, and subsequently find out I got the dimensions wrong...LOL

Front of floor will be supported by firewall , rear by body , center can be supported by seat riser..... my seat riser is attached to a tube steel truss.....
dave

I'm kind of screwed on using the firewall or rear of the body for support...both were unnecessarily cut out by the previous owner. I had been planning on using the seat riser to support the floor, but with trying to put a bench seat as low as possible there is not enough height available for something spanning the transmission tail. The good news is that the transmission crossmember is only a few inches farther forward

 

[RatchetRob]

Didn't think about the firewall supporting front. That eases that worry.
Thinking I will add some strap to bottom of sheet metal tunnel to form flange Zandoz. then glass that into floor.

 

[2old2fast]

Unless you're using some thick steel for the tunnel , it's shape doesn't yield much strength. The only place you need any support is at the point where the front of the seat weight is supported. This could be accomplished w/ a truss configuration or by having a "split" crossmember [2 seperate pieces extending from the frame. One way or another , because of where the frame is located[inboard of the body lip] and the short distance the floor is unsupported , it's not going to take alot of help for the floor to hold the weight ...
dave

 

[cooter]

Got pics?

 

[benT]

Here is a shot of how I did the trans and driveshaft tunnel on my '27. The trans cover is one piece and the drive shaft tunnel is another. Both are aluminum that can be removed from the topside.


As for my frame, there are secondary 2x2 tubes that tie to the trans cross member that triangulate the frame. My body is not channeled over the frame.


On the Purple Powder Machine, the drive shaft is under the back half of the floor, so its not cut in 2 pieces. The frame has a couple cross members that support the floor.

 

[RatchetRob]

Didn't get very far physically but mentally I think we accomplished a lot. Got a direction to head in and a flexible plan on how to tackle these issues. Had a helper Saturday and it was good to have some fresh perspective on how to tackle issues. Got the floor cut and my buddy Jon tacked welded body tabs to frame. Also got template for firewall cut as well. Then we put floor in and mocked up a bench seat. Then I got in and started feeling my way around where I wanted things and whatnot. I swear no motor sounds were heard! lol


Couple questions I have is, I keep reading that just regular bondo is the best to glue in wood floor and braces. Then fiberglass them in. Is just your regular bondo fine or a specific type?
Second question is, how much gap should be between trans cover and transmission? Is 1" adequate? Thanks More pictures to come.

 

[cooter]

lookin good..

 

[benT]

Rob, I like using the filler with short strand fiberglass in it. You can get it it autozone or Napa. I think it bonds better with the fiberglass. Make sure to clean and roughen up the fiberglass flange first.

As for the room around the trans, 1" is plenty.

 

[2old2fast]

X2 on the short strand filler , has more shear strength....an inch is plenty ...progress !!!
dave
You really dont need plywood on the firewall

 

[RatchetRob]

Ben, you and I have the same body from Cromwell. Did you plywood the firewall? Seems pretty flimsy up there Dave.

 

[benT]

We did. Used some 1/2" cdx. Gave some thing solid for the gas pedal and linkage (and firewall metal) to mount to, even though we through- bolted all of them. Stiffened it up a bunch.

 

[Indycars]

I swear no motor sounds were heard! lol

Like you expect us to believe that!!! hehehehe!!!

 

[RatchetRob]

Can anyone tell me what the total distance from frame rail to outside of master cylinder is? Trying to decide to use a firewall mounted or under floor mounted master cylinder setup. I have a 400 turbo trans and need to know if the master cylinder will fit between the rail and tranny.