Coupe into Speedster Conversion

[Tony G]

Nice work Justin, hope to see it personally soon!

[DG58INNM]

Justin,
I dragged my lazy butt out to the barn this evening. Found that all three of my cars have slightly different measurements to pan location landmarks. Big surprise huh?

Anyway, for academic interest, here goes.

All measurements are from the vertical bulkhead where the master cylinder/pedal cluster mount, at the left bolt hole.

#1 is rear edge of the circular depression
#2 is center of pedal mount bolt just behind rear depression
#3 is apparent centerline (top) of transverse tube
#4 is forward edge of the big depression in the rear pan

chassis floor---------#1-------#2-------#3-------#4
89379 original------8"-------8 3/8"---31 5/8"--41"
126687 original------7 7/8"---8 3/8"---31 1/2"--40 7/8"
104006 repro (simnsn)8"-------8 5/8"---31 7/8"--41 1/8"

Take care,
DG

[JTR70]

Hey Tony, Thank you! So nice to see you finally logging in and posting; Welcome! Sure anytime! BTW: Jeff (ciscokid is a long time Porsche nut who has just moved back into town. We'll all have to get together some time soon. Thanks again for being here! Justin

Hey David,
okay, I'll use your landmarks and take some measurements tomorrow. I have two cars here with original floors so we'll see how they come out..
1/8/14
A very abbreviated session this afternoon and mainly formed a plan of attack as far as welding sequence.

Decided to begin from the forward center then out to the edges. Drilled and installed a few self-tapping screws to draw these two pieces together tightly before welding. I have cleco pins but found out several years ago while repairing the battery box on my coupe that screws provide much tighter clamping force.

Another reason I have decided to leave the sides loose for now is this gap found on both corners. I'll need to torch-heat the floor here to be able to draw it down tight and contour it to this lip. The sides need to be loose to allow the amount of stretch and movement I need. Working on that tomorrow. Thanks for watching this! Justin

[Ciscokid8]

Justin, just tell me when!

[Tony G]

That would be great, I would love to meet other 356/911/912 fanatics like myself here in the LV valley. We will have to setup a time so I can meet Jeff and have a chance to catch up regarding our projects. By the way, I am very near to needing a chromer and do you know of anyone who polishes glass? I need to remove some light surface scratches on my 912's driver side glass before I reassemble the door (I rebuilt the window regulator mechanism)? I would love to chat with you regarding some nerdy engineering/technical matters I am currently working on at the moment.

[JTR70]

Thanks Tony, we'll plan a day here shortly Jeff...

David, I finally got around to those measurements:

Chassis.........#1......#2........#3..........#4
58367-original 8", 8 3/8" , 32" , 40 1/2"

Original floor
58 T-2 coupe 8" , 8 3/8"(just over) , 31 1/2", 41"

Some slight differences in length across the pan halves.

1/11/14
Drawing up the corners and leading edge of new pan.

Began torch heat and hammer work to the inside floor corner to get it to stretch and contour to this flange. This is after a couple of rounds.

It wasn't all just floor stretch. I also heated and shrunk this outer flange to meet the new panel the rest of the way.

With this corner shaped I could begin plug-welding the sides down to the flange.

referring back to the original floor on my coupe the factory seam welded this corner just past the shoulder. weld replicated here.

Onto the right side and Leap frogging my screws and gradually replacing them with a plug-weld as I draw this side as close as I can before applying the heat. Repeat tomorrow; so far so good. Thanks for stopping by! Justin

[Phil Planck]

Looking good Justin. Nice work on fitting that corner and replicating the factory welds. Surprised to see you use Phillips heads screws. I use the TEC screws based on a recommendation years ago from Bruce. Hex head, which imo is much easier to install and remove, plus self drilling and tapping. You can see one in this pic where I used 3 along the top of the flange to hold the new rocker in place.





Phil

[merbesfield]

I am surprised the floors are that off. I don't understand why they don't have the dies correct?

[Ciscokid8]

Too much of that great German beer?

[JTR70]

Thanks Phil, I think you guys are onto something I like those better; next time I'm at the hardware store I'll pick up a box.

Mark, the stampings in this floor are a little faint in areas and the forward section is one of them. This is only the second floor I have ever installed. The first one was in '07 on that speedster project and we used Zim's Simonson supplied floors.

Here it is and as you can the relief at the edges is well defined and I did not have the issue I'm running into now. Like David Gensler I think I'm now sold on Simonson floors. The floor I'm working with now is from Stoddards and is supplied by Restoration Design. Watching Phil and Tom struggle with making thier rocker panels work I think I'm going with Simonson for those as well. BTW: I did have fitment issues with the Simonsen battery box front closing wall meaning none are perfect but I'd like the best stamped piece available.

[JTR70]

1/17/14
Paper template complete as Steve Hogue requested.

Wrapped this little chore up over last weekend and sent it off.

Steve confirmed he's got it so we should see this new part in a couple of weeks.

In the mean time I'm continuing on welding up the perimeter of this new forward pan.

My original floor and cross member on my coupe has this leading edge seam welded across however they stopped at the pan. I decided to take it just a few MM's further and include the pan for more tie in strength. Basically still correct and most would never know the difference.

Plug-welding down the sides as well and am also replicating seam welds were originally done. The factory ran a seam across that "V" junction on the floor as well as a few other places I'll show when I get there.

Original seam detail on my coupe. So glad its here for reference!
Thanks for looking! Justin

[JTR70]

1/28/14

New chassis parts:

Steve Hogue came through on that rear vertical closing wall and I should have it in my hands next week.

Embossments and details look good! Trimming and fitting of course but what a nice looking start.

New donor rear seat pan with cross-member arrived on Monday.

Excellent, solid, rust-free original chassis parts. Only draw-back is they were cut short ahead of the mount flanges so I'll be fabricating those simple repairs.

Original seat pan and cross-member is of course severely rusted out and heavily pitted.

Both lower corners are gone and repair patches were considered but on close examination the rust is very advanced throughout the cross-member.

Other side

The cancer is not localized to the corners; heavy pitting and rust damage runs all the way up its walls.

A cosmetic cap is not going to cut it; the rust runs too deep.

This is the business end of this chassis. The weight of the drivetrain and the torsional force of its operation runs through this cross member. I wouldn't want that thin rusted out old anchor-point in my car. This replacement is a must as far as I'm concerned. Prepping this area until my wall arrives from Steve. Thanks for stopping by! Justin

[Phil Planck]

Well you have your work cut out for you now Justin. Great find on the donor parts. Steve is a great guy. Never met him, but he asked me to call him when I was trying to repair the badly damage passenger fender. He spent a lot of time on the phone with me with great advice for how to fix that fender. Unfortunately, it was still beyond the scope of my abilities. If I ever get out there I would love to tour his shop.
Good decision on the repair strategy.
Phil

[merbesfield]

I too noticed that the Simonson pieces seemed more defined, at least in the pics. On another subject, have you noticed that your self drilling screws are only good for one or two uses before they are too dull to reuse? That's what I have found seems a waste to throw them away, but nothing worse than fighting w a .02 cent screw.

[roy mawbey]

Wow, Justin this thread gets more and more interesting the deeper you go. Some nice work here, and that item reproduced by Steve looks great. I have watched his 'you tube' videos that guy really impresses me the work on those early 356 cars by him is just great.

I still get surprised at the rot you can uncover when everything inside is removed. The depth of rust damage can so easily remain covered up unless go to the degree of removing all carpet and sound deadening panels.This is where buying an old 356 could still be a problem even with a PPI. Those back area's are just so diffcult to see and establish if good or bad.

I have never had wet carpets and I have in the past banged on those panels with a flat faced hammer seems all sound and from underneath as far as I can see also its okay but I would really like to know for certain. ( But the carpets will not be ripped out just to see.)

Roy