Spriso's SR20DET Bluebird Coupe Project

[spriso]

Bird On a Stick

Now that the car is clean, the slow process of rebuilding the rusty areas of the car can begin. The first thing I wanted to get done was modifying our Datsun Roadster rotisserie with new mounts to suit the Bluebird. Of course, this took much longer than it should have, but I am very pleased with the results-- the car turns easily, the roof clears the floor (whew!) and I can now get to all those hard-to-reach spots.



Underside mounted at 90-degrees:



With the car at 90-degrees, I did find a few more rust holes under the crossmember on the core support, so add that to the list of things that will be getting rebuilt...



More soon,

Michael

[defdes]

What's the deal with the rust preventative they added, will welding it be a noxious mess a la galvanization?

[spriso]

Defdes wrote:

What's the deal with the rust preventative they added, will welding it be a noxious mess a la galvanization?

The coating is a very thin rust preventative-- it is not like galvanizing. But like any treating, you would want to clean it off before welding (which I will with a Scotch Brite wheel). The whole car will be sanded down with a Scotch Brite pad when it comes time to do the epoxy primer, but for now, it can stay in this finish (as long as it does not get too wet).

Michael

[spriso]

Behind the Blue Door

When the body was stripped, I did not send out the doors to be done-- one because I have a NOS passenger Coupe door, and two, I knew that I needed a better donor door for the driver's side.

Knowing that the 2-door sedan door shell was essentially the same as the Coupe version, I would just need to swap over a Coupe window frame. Since I want to keep my existing Coupe door intact (in case of an accident in the future), I decided to source a window frame from a donor Coupe door in Japan.

I talked with Craig Ford, and he found a suitable door frame from a rusty Coupe door which was beyond saving-- since that was sourced, I started on this project.



First the sedan door. I have had this door way longer than I would like to admit. It was pulled off a 1969 2-door sedan which was totaled in 1970, and it was given to me in the early 80s, and it has been in my care ever since-- dry, rust free, and with original paint still gleaming, it was the perfect donor door for my Coupe. A few minutes with the spot weld drill, and the sedan door frame was free of the shell:



The Coupe window frame needed to have the remains of the stock sheet metal removed before a test fit:



But first, some measurements-- I will need to be sure that the window height is set at the right height upon re installation:





After that was documented, the remains of the sheet metal were dropped off to be dipped (we will talk about the wagon frame rails in another post):



Today, the door shell and window frame came back from the dippers-- nice and clean and ready to be reworked:









A nice study of the differences between the Coupe and 2-door Sedan Window Frame:





So, now I need to build a window frame JIG off of my existing Coupe door to make sure the angle of the window frame is correct, and just weld it all up... sounds simple, right? LOL.

More soon,

Michael

[spriso]

Wagon Rails

One of the things I always wanted to look into on a 510 was adding full length frame rails from a Datsun 510 wagon. The wagon, with it's longer roof (and probably the need for being able to handle more weight and cargo) had redesigned frame rails that run the entire length of the floor-- unlike the frame rails that stop half way on the sedan.

Since the Coupe is naked and on the rotisserie this would be a good time to explore if this was an option. I made a few phone calls, and Steve Epperly in Salem had a wagon floor which had been harvested (to save the good floor panels) and he offered this to me for this experiment-- a quick drive up to Salem and I had what I needed:



A little fun with the spot weld drill and I had my first frame rail harvested:



And soon after, a pair on the floor of the shop:



These were dropped off at the dippers last week, and came back nice and clean:



Next up was to remove the stock Coupe frame rails-- Ralph Kenyon was up last weekend, and I put him to work with the spot weld drill:





We slowly worked off the panel, breaking each spot weld free:





Once the panel was removed, the nubs of the previous spot welds were ground down and the panel cleaned with a wire brush:



A test fit looks promising:



Follows the floor profile well:





The front and rear of the frame rail had been cut off when they originally harvested the floors and they will be rebuilt along with a new box section in the rear.. The wagon rails are deeper than the original 510 frame rail too, so this should had some torsional rigidity for this chassis-- especially good for the smaller B-pillar that the Coupe has compared to the 510 cousin.

More soon...

Michael

[RMS]

I used a wagon floor pan on 6inches of rust for the longer rails. I just wish I had a good set of front uppers rails as those too are bigger.

[two_68_510s]

My friend has done this to his two Z cars. although they used custom made channels. He was very pleased with the results, as he has higher than normal HP!
Love the idea of using the benefit of the giant presses over in Japan!

[spriso]

Work Continues

I have been very busy all summer with customer projects, and traveling for work, and have had very little time to work on the Coupe... finally I had a few hours to spend, so I welded in the new floor patch panel and first of the 510 wagon frame rail:

Frame rail and floor removed (damn, that is a big hole!):



Fitting the new floor panel:



Welded into place-- the front seat frame rail has been removed and will be reinstalled rearward to provide more leg room later:



Frame rail welded in from above, and then below:



After it was spot welded in from the top, the edges were stitch TIG welded with silicone bronze:



Again, the rear edge was cut off when these were processed out of the donor wagon, so I will build those, but I am also going to incorporate them into the rocker panel, so more work to be done there.

Next up is the passenger side floor board, and then the frame rail replacement--- then the rocker panels--- I've got a long way to go!

The corner where the front upper air channel meets the a-pillar is modified on the wagons, so a similar brace was built for the Coupe.

Before: Metal cleaned before stitch welding:



A CAD template was made to show the gusset, and still allow for the drain hose to exit from the cowl drain to the inner fender (which has a downward slope, hence the offset holes):



Stitch welding with silicone bronze:



The metal behind where the gusset will be welded was painted with metal etching primer and then seam sealed:



New gusset built and ready for weld:



I'll have to get a shot of everything all in... but it was all welded in, fender clears, and the drain hose fits perfectly-- on to the next side!

More soon,

Michael

[greenthumb]

Inspiring work as always. This project will be amazing once done!

[two_68_510s]

Michael, thanks for the comprehensive documentation.

[yenpit]

I've always wondered how much of a job it would be to pull the window frames out & replace............NOT from damage or swapping the shell like you did, but to potentially SHIP 2dr doors to another country, saving quite a bit in package sizing! I've had a guy in Asia & at least two guys in Australia wanting doors & B pillars, but they can't seem to grasp how easy this would be! Anyway, cool project, can't wait to see assembly!

TJ
Denver

[edekalil]

Very nice build with all kinds of info. I have one of my 510’s apart and on a rotisserie now so this thred is giving me inspiration.

Thanks

[Byron510]

Great work Michael, it’s always a great to read your posts.

Question: How did you form the recessed section in the floor panel? It looks beautiful.

Byron

[spriso]

Byron wrote:

Question: How did you form the recessed section in the floor panel? It looks beautiful.

Can't take credit for that-- these panels came from Mario at TSR-- he has a die that he uses and presses the relief into the panel which makes it very strong and stops any oil canning. I was down in LA visiting him in April and he had a bunch that he had just made, so a pair came home on the plane for this car...

Thanks to all for your positive comments-- the struggle on this project has been finding the time, but I'm slowly chipping away at it.

Michael

[spriso]

Thanksgiving Update

Had some time off of work, so I got down to the shop and made some more progress on the Coupe.

First off was finishing the passenger side front floor board-- but that required the backside of the rocker panel to be replaced on the front section as it was heavily pitted:



With that in place, I could install the replacement floor panel as well as the other wagon frame rail which was plug welded from the top, and seam welded from below:





With the floor fully welded in, I then could move the front seat mount back 4"-- I always hated how the seat is all the way back whenever I drive a 510 and there is now way to move it further back if I had a taller driver. Seat height was fine, I just wanted more leg room. Since no one is going to be sitting in the back seat-- this was a perfect time to move the front mount back. The stock front seat mount is an elegant, light weight design, and when it is welded into the car, it is a solid mount. I just needed to modify the brace a bit to match a change in the floor profile, and it was good to go. The rear mounts will be modified and floor reinforced soon.



Next up would be the rocker panels and doglegs. The rocker panel backing plate (which the floor attaches to) was cleaned up and damaged areas repaired (an earlier shot before all the welding was done):



The rear of the driver's side rocker panel backing plate had some deeper corrosion and damage from jacking that needed to be replaced:



Now upside down (the rotisserie makes these repairs awesome) with the offending parts out of the way, it was time for a deeper look:



The backing plate and the transition into the wheel house would be replaced with a new section of 18ga mild steel:



A second layer was built just like the original to strengthen the corner:



And welded in:



The folded edge was also replicated to stiffen the transition as well:



With a good foundation, now the rocker panel could be fitted and dogleg cut to match. But first, the terrible fender rolling that a previous owner did had to be undone to gain access to the dogleg:



Now, I could test fit the rocker panel, a NOS part that I have had sitting in the attic for about 25 years-- and it fit perfectly:



Since I am replacing this quarter panel, I opened up the wheel well so I could see what I was doing for the dogleg replacement:



95% of the rear inner fenders are clean, and rust free, so I decided to splice the inner fender with a replacement from FutoFab. I used the original piece as a pattern for a rough idea of what I would need to cut:



And a test fit looked promising:



Sadly, the profile on the dogleg where it overlaps the NOS rocker panel is not as clean and sharp as the original panel, but that can be sorted once it is fully fitted (and it's covered by the outer skin of the quarter panel:



With that completed, the back sides of the rocker panels were painted with sealer primer, and the edges primed with weld thru-primer, and after dozens of test fits, both rockers were finally welded on:





More soon,

Michael