Model A job

[idrivejunk]

I worked on body mounting Thursday and roll pan Friday. Going fine.

These fuzzy tablet pics will have to suffice but pic quality should return to normal next week.

[jaybee]

Glad to see you got to a workable solution...from among several good ones.

Maybe this is going off on a tangent, but I think you made a good point about the body and chassis depending on each other for stiffness. I'm asking here due to your collision repair experience. Of course we've got other people here who run or have run shops including Frank. The hot ticket in the muscle car world these days is to spend $14G on a full frame to put under a unibody car...then cut up the unibody to handle all the places where the new frame interferes with the underside of the car.

I'm sure that works well enough, but the resulting car has to be really heavy. After all, it has all the structural integrity of TWO cars...one body on frame, one unibody, albeit perhaps with the unibody compromised.

Might it be better to instead include/mimic the factory reinforcements added to special models? As an example, Mustang convertibles through 1970 had:
--Doubled floor panels under the front seats which tied together the front subframe, rocker panels, and turned the lower radius of the driveshaft tunnel into a triangular tube.
--Different (structurally stronger) seat platform.
--A plate to connect the two sides of the driveshaft tunnel.
--Inner rocker panels which ran from the front torque boxes to the rear torque boxes.

Shelby Mustangs triangulated the shock towers/fender aprons with:
--Export brace--one piece version of the stamped steel firewall braces used on standard Falcon-body cars.
--Monte Carlo bar.

Boss 302 Mustangs had:
--Pieces which triangulated the heavy part of the shock tower where the upper control arms mount to the outside of the frame rail.
--On track cars they tied the lower control arm mount to the bolt on crossmember which runs under the engine...engine crossmember or "belly bar."

Sometimes Mopar builders will brace the fender aprons to the outside front corner of the unibody, way up at the top flange and A pillar area so it's out of the way of tires.

In the rear seat area use a firewall firmly attached to the floor, package tray, wheel wells, and usually there are some shallow braces between the floor and package tray to stiffen things up.

Maybe there's a time advantage to slipping an Art Morrison or Roadster Shop chassis under a unibody car which makes it less expensive for a professional shop, but given what I've seen it seems unlikely. Obviously you get a bunch of cool tubular control arms and the like, but you can get that anyway.

If you take the approach above you don't get to power park with a sign that says "MaxG chassis," but other than that I see adding a whole bunch of stiffness with a lot less performance-robbing weight.

If this hijacks your build thread I apologize and maybe we can take it to another thread...should anyone be interested.

[enjenjo]

If anyone likes I can give a run down of some of the history of the migration from body on frame to unibody.

[chimp koose]

Part of the slipping another frame under the car thing is the speed of turn around in the shop I would think . The shop makes their profit margin on the frame and charges shop rate on the install , no complicated design work that you might have to eat if it runs into problems . Customer gets bragging rights on the XYZ chassis and gets to look like all the other big wheels at the car show. I ran into this with a co worker who wanted me to do a drivetrain swap in a Fiat X19 to some Honda setup. There was a bolt in Kit available for about $6000 and he thought that was expensive and wondered if I would be interested in making him a swap setup . I explained to him that at a shop rate of $60/hr all it would take is 100 hours and we would be at the cost of his kit{shop rates around here are north of $120/hr) . All the measuring of both vehicles and suspension etc , mid engine car , designing and fabricating etc might put a guy pretty close to that number anyways . If he buys the kit he can start swapping right away . Not saying its the best way to do things from an engineering standpoint but it keeps things less complicated /more profitable and the customer has a vehicle with a nationally advertised chassis under it that may be easier to sell some day . Thread officially derailed , sorry  :oops:

[idrivejunk]

Jaybee-

Honestly now that the outer panels are where they go on the A, I would just as soon chop out the upper part and put up a sheetmetal inner layer instead, in anticipation of a cage being added. I never been a big tubing fan and my experience thus far is that it can be difficult!

To answer your curiosity, I say look to the Catalina. If you cut the entire floor out of a car body, thats a blank rectangle from bumper to bumper.

There is no reason I can see that a universal fabbed here or stamped over there all sheetmetal chassis and floor in one assembly with adjustments to fit any size and holes for popular everything couldn't be a viable offering based on where things are headed. Get the right size front and rear chassis sets then grab the right sheetmetal flange adapter kit for your car and take that to checkout on this cart. Have a good day, sir!.  

I also don't see any reason that in the case of the A, that if the customer wanted me to I could not weld the body to the frame.

Remember the quick scraps that join floor pan to seat braces? Easy to chop out. It will need a seat brace or mount gussets at the very back.

Have lots of thots but can only do whats in my stall. Have I thought of doing a lightweight engineer to my GP? You betcha. Tube frames just hit the market spot and suit the majority. And as one might find, shaping sheetmetal beyond 18 gauge is not for the meek or most tools. You need some of at least that around the subframe or suspension. Thats probably why you don't see it.

[idrivejunk]

If anyone likes I can give a run down of some of the history of the migration from body on frame to unibody.

Shoot  

[idrivejunk]

Part of the slipping another frame under the car thing is the speed of turn around in the shop I would think . The shop makes their profit margin on the frame and charges shop rate on the install , no complicated design work that you might have to eat if it runs into problems . Customer gets bragging rights on the XYZ chassis and gets to look like all the other big wheels at the car show. I ran into this with a co worker who wanted me to do a drivetrain swap in a Fiat X19 to some Honda setup. There was a bolt in Kit available for about $6000 and he thought that was expensive and wondered if I would be interested in making him a swap setup . I explained to him that at a shop rate of $60/hr all it would take is 100 hours and we would be at the cost of his kit{shop rates around here are north of $120/hr) . All the measuring of both vehicles and suspension etc , mid engine car , designing and fabricating etc might put a guy pretty close to that number anyways . If he buys the kit he can start swapping right away . Not saying its the best way to do things from an engineering standpoint but it keeps things less complicated /more profitable and the customer has a vehicle with a nationally advertised chassis under it that may be easier to sell some day . Thread officially derailed , sorry  :oops:

Interesting points. See my other post and think universal adjustable RWD front engine, two or three sizes fits all old car floor/chassis assembly combo sets in thirds from Taiwan with a-dapter kit and SAE threads. Available for gas or electric versions, would you like it assembled and wired?

[idrivejunk]

You guys are lucky, see... now you have seen how one other person (me) would end up building. If you liked parts of the design, theres your pattern.

[chimp koose]

Interesting thoughts , just spitballing but I have thought that a prius or similar drivetrain would be a neat modern swap into an early center door T . I have never even looked at the drivetrain to see if it might work and at the speed I do things I would need to be a spry 100 year old to complete the task !

[jaybee]

If anyone likes I can give a run down of some of the history of the migration from body on frame to unibody.

Heck yeah, that would be interesting.

[idrivejunk]

I suppose I could even out the shagnasty upturned inner lip on the grille shell by trimming. And I suppose I could reattach the old cowl lip or fab a resemblance. But those look so yuck. Anybody got an option E for me here? I have a few ideas-

[jaybee]

I vote "C." It hides the butt edge under the seal, creates a nice, rolled edge, and will be plenty strong.

[idrivejunk]

C is growing on me. I keep wanting to just fab the part under the hood top and put the original edges back. It had a line of rust just under where the old chrome molding went and thats gone now. I think I have the front edges from the cowl sides but if I recall correctly the top section was part of the tank. Or a seperate piece. I probably cut a front edge off the new smooth cowl top panel.

Every time I have gone to the keep scraps to fish out those edges, I have been distracted by a tangent and not done it. Today it was the overslam bumpers off the rumble setup. I keep wanting to put those in the bottom corners of the trunk lid opening now but no-no they don't work with the redesign. Wonder how many times I've done that. Does this behavior indicate that retirement is approaching? :?  :?:  

I don't feel so bad about that after learning more about earth's history, what with mankind itself being stuck in a repeating loop and all.  

That thought ran long. Another age alert, haha. Pics coming up next. I spent the day at the other end of the rod.

[idrivejunk]

I just knew you wanted to see down in that briar patch.  That area gets capped off with filler pieces already made. Do you guys think I should box the backside of the roll pan, between fenders where its one layer? Looks like a pebble collector / air scoop but will probably fly with just the fillers. They go in line with the inner tub wall.

This is just a peek at where the engine sits now. Much better, and the gas pedal position  (right heel area to-be) is still not objectionable to me at this point. But now theres a sportin' chance of getting all the things betwixt engine and radiator.

[idrivejunk]

Once I got to messing around under there I noticed that moving the body forward had created a tight spot at the top rear of the frame-



With shims, it was almost making contact. So I decided if you want the shock mount bolts to come out of the frame, raising the body will be required henceforth. Made a new drop-off panel and it is slicker than before. I will also box the backside of the roll pan with another panel.

Until today-



Cut the drop down part of the trunk pan ext'n out-



Whipped this out-





So it is like this now-





The top part all hides behind the frame from underneath.