1949 Desoto Convertible Update

[James_Douglas]

Hi all,

I thought I would post a few photos of the work on the 1949 Desoto Convertible. We are getting close to taking care of any and all issues sheet metal wise. 90% of the problems are in the trunk. We cut out metal and removed all the rust and did some slight modifications to the rear section.

The rear frame on these is not a very strong part. On mine it had a tweak from someone locking it down on a flatbed or towing with it. On the convertibles the spare tire does not sit in a well. However, Desoto still used the same rear frame member with the large drop on it in the convertible even though you do not need it to drop down. Because of this fact, we made a straight rear cross member out of a thick wall steel tube and welded it in. We dilled holes in it and welded steel tubes in the member so that we can bolt to it and not collapse the tube. Getting it ready for a hitch if ever desired.

The rear of the trunk is made up of a sheet metal box section that was spot welded together. After cutting out the rust we rebuilt the bottom of the box and then added a rectangular steel tube that is welded inside of the sheet metal box. We also added a 3rd body mount directly below and behind the trunk latch. We added a stand off to the new rear cross-member to bolt to. We then welded up the top side of the box. As a side note, we extended the heavy tube in the box out past the flange of the inner fender to trunk junction and so could weld the heavy tube to the bottom of the inner fender quarter so the load path was not on the spot welded flange. Much stronger.

We had to repair the lower corners of the trunk seal area on the body as it rusted as did the lower rear quarters. Funny, in the convertible they left little "pockets" at the back inside and crud collected and rusted the body. On the sedans I have seen they did not. Odd.

We need to do a little work on the sill on the drivers side. Crud on the inside held moisture and it rotted through. The passenger side is fine as is the doors. The drivers side floor pan has no holes and some surface rust, while the passenger side has about 3 pin holes which we will weld up.

All the inner and outer fenders, aprons, and the like have been blasted and the one that were back have been powder coated. A few minor items but nothing to write home about.

The duel single master cylinder with balance bar mock up is coming along and looks like it will work out fine. I decided on a 1" master cylinder for the rear and a 7/8" master cylinder for the front. The Tilton mount will work out well once we build a plate for it to bolt to. We will use a 27 inch chrome moly (with Mill Cert) rod to go through the orginal MC and then the convertible x-member and then into the new MC mount. A rod 5/8" will take the load.

Looks like the ability to bolt on a Ford/Curry 11" x 2.25" self-adjusting drum brake assembly with integral emergency brake will work out. Will know for sure in about 2 weeks.

Trying to get the car to the body shop in 2-3 weeks. July and the National Desoto Club meet in Reno is coming fast and it will be a race to see if I make it.

Best, James

[PatS....]

Looks like it's coming along very nicely James...especially considering where you are working.

Thanks for the update...I was wondering how the project was doing.

[Don Coatney]

Looks good James;

Will your master cylinder be located under the back seat? Have you converted to disc brakes on the front? Will you be using a vacuum booster on your master cylinder? If not have you calculated how much foot pressure will be required to push the pedal with the different sized chambers in your master cylinder?

Your name came up when Billy Austin and I got together a couple weeks ago.

[greg g]

James whatever became of your Jaguar??

[James_Douglas]

Hi Guys,

I have been at it 8 hours days for the last two months. This is too much like real work! Fun, but hell on my back on the cold concrete here in San Francisco.

I was going nuts trying to cram everything into the garage here. I was just about to put the XKE into storage when...several of us visited a XKE guy south of San Francisco. He had a 1969 Coupe project and wanted out help with some information. So four of us went down and looked at it. What a mess. He could spend years and $20K on the body alone and still it would not come out good. We told him the bad news and then headed home. That night, I thought about my XKE, the fact that I want to buy/rebuild an antique airplane in the next few years, which means building a hanger....and get the '49 going. So, I made him a personal offer to buy the car. He really wanted and early E-Type coupe so he jumped at the chance. I sold it to him and now I am back to 2 cars in my city garage space.

On the brakes on the 1949. I purchased a front disk kit from ECI like I did with the Big Desoto. In retrospect, I would not have done that. I had some issues like you had Don. On the 1947 kit, it was custom made on my factory hubs and worked and fit well. The "kit" for the 1949 needed some work and even when done pushes the new hubs out about 3/8" from stock. Since I am have wheels made up I can account for that. But, I think that using brackets and doing the stock hubs, in retrospect, would have been a better way to go.

The convertible has a "X" member. If not, I may have gotten a duel in line MC kit from someone or just made one up. The problem is that it is very tight with the "X" frame. I also like the factory pedal set up.

What we will do is put the duel single master cylinders behind the "X" frame. A steel plate with stand offs will go over the side and "X" frame tops and the Tilton unit will hang down from that. Easy to weld the plate in place. I can then look at and see all the linkage easily from the ground looking up. It also has a knob to adjust the bias and so I do not need to use a proporting valve.

Since I can match the pressure requirements individually to the drums and the disks, I should not need any kind of power booster. I have done the math and everything on paper looks good. The Tilton MC's come in several sizes and if I need more pressure, at the expense of added travel, I can easily swap out to a smaller bore size.

If this works well, I will do the same thing to the big Desoto and Don Barnes is thinking about it for his all drum '46 Town and Country. The push-rod length will only be about 10 inches on the big Desoto as I have all the room in the world along that frame rail.

On the subject of MC push rods...I am going to use 5/8" Chrome Moly with the end connecting to the Pedal milled flat one the sides and a hole like the stock one. On the Tilton balance bar end I will either drill and tap the rod to take the heim male heim joint or turn and thread the rod and use a female heim joint. I just have to decide which I think would be stronger.

Best, James