54 C/K frame fix

[oldguy]

I have a 54 frame and a 53 coupe body. Frame appears to be straight and solid. Small crack by the passenger side front crossmember and some rust swelling in the "batwing" crossmember. Fixing/reinforcing those shouldn't be a problem, but I want to do more. In the forum search I haven't found a comprehensive outline of what to do.
Considering: 1. welding a plate along the inner frame rail from front crossmember to the front rear spring hanger, or all the way to the rear most spring hanger. 2. fabricating an X member for torsional rigidity. 3. reinforcing the floor pans, etc. so the body helps the frame. 4. Using metal shims on the body mounts and actually welding the body to the frame, for a "unibody" effect.
Opinions very welcome.

San antonio TX. 53 Champion Coupe, to be brought back from the dead.
"Of course it will fit, I have a torch"

[Chucks Stude]

How much of a hotrod are you going to make out of this vehicle? Boxing the frame in high stress areas will be helpful. On the body I would consider the stronger (thicker) body supports from Classic Enterprises. I know that these things have helped my GT. However, solid mounting the body INMHO would be counterproductive. It transfers a lot of noise and vibration to the body. If you are not going racing, I would not do that. Besides, wasn't the 54 frame an improvement over the 53? Or is the memory slipping out of gear again.

[oldguy]

maybe a "Mild hotrod"? Not a monster, but I have dropped V8s in old cars before and suffered shuttering and flexing that I'd like to eliminate this time. Yes, the 54 has the extra batwing body support, but the frame is the same. So it leads me to think the frame needs help. You may be right about the "unibody" causing it's own issues. Thanks, that's why I want other heads to ponder the choices.
As far as beefing up the high stress areas.... exactly where would that be? My "plan" (?) was to weld a 3 or 3 1/2 inch plate (13 gauge same as the frame)along the inner frame rail. Maybe some 3/8 holes every 6 or 8 inches along the center that could be plug welded. Seems that would go a long ways towards removing any sag, but what about torsional flex?

San antonio TX. 53 Champion Coupe, to be brought back from the dead.
"Of course it will fit, I have a torch"

[S2DSteve]

Don't overlook the body itself. One of the things I did to reinforce my convertible is build a layer of fiberglass resin and heavy fabmat over the entire floor and up the firewall and back panel. In addition to reinforcing the whole body/frame assembly, the layer insulates against heat and noise. I did the same thing to a Starliner years ago and the improvement was very noticeable.


Steve Hudson
The Dalles, Oregon
1949 "GMOBaker" 1-T Dually (workhorse)
1953 Commander Convertible (show & go)
1953 Champion Starliner (custom/rod project)
1954 Champion Coupe (daily driver)
1960 Hawk (future project?)

[Chucks Stude]

Steve, my question on all of that fiberglass is how much weight did you add to the car? A rollbar might be the other body mod that might help the structure.

[55s]

Do check around the front spring pockets for cracks as well.

Paul R

[55s]

Do check around the front spring pockets for cracks as well.

Paul R

[buddymander]

I like that fiberglas on the floor idea. My Gt could use something like that for added protection against rust and my truck could sure use some road noise dampening.

[S2DSteve]

I'm not sure how much weight it added-maybe 50 lbs? Imagine a 4x8x1/2" sheet of fiberglass. The convertible also has plate steel reinforcement on the frame rails and a 1" "ladder bar" assembly under each frame rail front to back. Obviously weight saving was not a concern (it now weighs around 4000 lbs) but it rides solid, cool and quiet (other than ridiculous wind noise).


Steve Hudson
The Dalles, Oregon
1949 "GMOBaker" 1-T Dually (workhorse)
1953 Commander Convertible (show & go)
1953 Champion Starliner (custom/rod project)
1954 Champion Coupe (daily driver)
1960 Hawk (future project?)

[fstst56]

Aren't Champion frames made of a lighter gauge metal than Commander frames? It might help tp identify which frame you have first.

[oldguy]

I think it is a 54 Champion frame. Never saw the car it came out of.
I don't believe there was a difference between 6 an 8 frames, back in the 50's.
S2DSteve -Have any pictures of that frame? Or a detailed description of the frame plates and ladder bar assembly.
55S - Where around the spring pockets? I don't see anything, but I haven't stripped the frame yet.

San antonio TX. 53 Champion Coupe, to be brought back from the dead.
"Of course it will fit, I have a torch"

[S2DSteve]

I do have pictures (prints) but I can't seem to download the scans to Photobucket. Anyway, the "ladder bar" is like an upside down suspension bridge, a 1" steel bar running front to back underneath the frame rails spaced out with steel tabs at about 12" intervals. At the center of the car the assembly hung down about 5", which was too much. After I fiberglassed the floor, I shortened the spacing tabs to bring the bar closer to the frame and increase ground clearance. The bars seems to have done the job, but I can't recommend it due to the ground clearance problem. The plate reinforcement is basically 3/16" steel plate welded to the sides of both frame rails, esentially tripling (or more) the gauge of rails. And again, the body itself was substantially reinforced with the fiberglass. I'm not sure how effective each step was, but the combination definitely did the job.


Steve Hudson
The Dalles, Oregon
1949 "GMOBaker" 1-T Dually (workhorse)
1953 Commander Convertible (show & go)
1953 Champion Starliner (custom/rod project)
1954 Champion Coupe (daily driver)
1960 Hawk (future project?)

[oldguy]

definetly going to plate the inside of the frame rails. If I can figure out how to get it LOW I forsee a driveshaft problem, which might be a blessing. I could build a higher tunnel and get the driveshaft above the frame rails. then I could X the frame, or ladder it. Looks like I better mock it all up before I do any frame work. thanks for the help.

San antonio TX. 53 Champion Coupe, to be brought back from the dead.
"Of course it will fit, I have a torch"

[wcarroll@outrageous.net]

Here are some pics of what I did to my '54 Commander HT frame -they might give you a few ideas. Take a close look at the plates I welded into the corners of the rear shock mount/over axle brace. This always seemed like a weak spot to me and it's an easy mod:

http://rides.webshots.com/album/453747682GrpcCM?vhost=rides

http://community.webshots.com/user/s2dbaker?vhost=community

[oldguy]

Wow. thanks. Better than I hoped for.
I notice you didn't plate the frame rails, and with that setup you shouldn't need it. Is that 3 in. square tubing?
Did you fabricate the driveshaft hoops? Not sure I can make those.
The phantom front end looks impressive. Can you tell me how much anti dive and positive caster is built into the setup?
Pics can deceive, but those look like drop spindles. Are you putting it low?
Thanks for sharing. Gives me lots of ideas, but if you don't mind I may just copy it as is. don't see how I could improve on that.
don

San antonio TX. 53 Champion Coupe, to be brought back from the dead.
"Of course it will fit, I have a torch"