Outstanding work,

Ooooof. My head is starting to hurt.

In looking at various 916/916 replica roofs, it appears they move the drip rail inboard by frenching it into the windshield pillar, then reshape the outside edges of the roof's curve, either subtly or dramatically - see pics for a couple versions.

In any case, it seems the reason is to retain the original width of the roof.

Do I care/will it look "off" if my roof is a bit wider than stock?

If you need me, I'll be in the shop thinking about options. And just a heads up: If I don't come up with something I feel I can accomplish (well) in some sort of reasonable time frame, I may just abandon the fixed roof in an effort to actually get this car "done".

Another day with far more thinking than doing. Probably an approach I should use more!

A big thanks to @ChrisFoley , who was kind enough to take a couple calls from me and allow me to pick his brain re: his experience with these steel roofs. He helped clarify a major issue I was stuck on.

With this improved understanding, I went after what I've come to call "the dreaded rear corner". This is where virtually every piece ends up intersecting.

I did my best to channel the Beatles "Come Together" and actually, it seemed to work out!

Note that the drip rail is a practice piece and will be remade, now that I've determined all the dimensions. But here it is with the drip rail/seal mount surface and the rear closing panel sitting in place. I also installed the targa stainless trim to be sure I fully understand the way everything fits/looks.

Next, I went after the horizontal return/overhang that will support the rear of the roof skin. It follows the shape of the closing panel and will then be welded to the drip rail.

Trimming remains to be done but things did "come together"! I think I'm liking this.

Lookin' good! I don't know if this is true or not, but I remember hearing that the windshield frame to body joint wasn't that strong. Maybe grab the top of the window frame and try pushing it fore and aft. Hopefully what I heard was wrong.

like this on my loweGT, done by AA...

But in the end I don't think it is much of an issue. I spent a lot of time on this one , then I said F'it, grabbed the 944 roof I had sitting on the floor, and a spare A pillar I bought. and started

The 944 and the 914 have the exact same gauge metal in the A pillar. The inner design is slightly different, but not to the point it bugged me. Three pieces welded together with slightly different inner profile. In the end, I thought about making pieces like what was in the Jon Lowe's #40 tribute 914. I spent some serious time around that car and build. And this is what I came up with. There was a 914 already converted with the 944 roof section. It was running around and driving. I have not heard a thing about A pilar issues, and still have not. And well the people who drove it, said it made a huge difference. So I went with the stop over thinking this shit and moved on to lets weld more into the car.

The difference between a GT top and a skinned top is the fact that one is bolted in 4 places, still allows flex to be transferred down the A pillar. And the other is a fully welded top. Every section of the skin becomes its own triangulation point. Overall it would be much stronger, while possibly being lighter.

Thus the reason the factory welded on the top to the 916 making it a true coupe. If the factory continued racing development of the 914 chassis, the 916 should have been the platform to go with. It just made that much more sense. Thus the Boxster and Cayman. I will take a Cayman everyday over the Boxster. Response is so much better.

Now back to the build

@Krieger Andy, I believe I'll be OK without additional stiffening of the A-pillars. As Stephen @914forme points out, others have used a "roof only" approach and nothing seems to have gone wrong. Fingers crossed!

Today was making progress on the X-brace. First I tacked in the targa-to-windshield bars. Boy, just doing that made a huge difference in locking the windshield in place. And that's just with a few tacks!

Then it was working out the corner locations for the main brace component. I ran a center line string so I could use it to center the middle speed hole.

I need it to fit on the bars in such a way that it has the desired clearance to the inner roof skin. I measured from the underside of the bar to the roof, then subtracted the height of the brace plus the amount of clearance I want for the foam/bonding agent. And of course it's a different dimension at the rear than at the front. What fun would it be if it wasn't?

Then it was the "fit, trim, check, trim, fit, check, repeat, repeat, repeat..." ad infinitum until it it was where I wanted it. Then I tacked it in.

WAAAAY more head clearance than that initial 1.25 cross member tube, @horizontally-opposed !

And I was able to achieve a pretty even gap across the curve of the roof.

On to fitting the other two pieces.

Niiiiiiiiiice work, Chris!!

I think the rain drop is too vertical, I think it needs to be flares out at more of an angle. Also it still might be too tall but that'll be easier to determine with the skin on.

At least this is in comparison to the 916 images.

Still looks damn amazing.

How much would it take to build up maybe an additional "V" brace along the inner A piller out of say 14ga? That would do a lot for strength, even just for chassis twist alone. You probably need to hog out some of the a pillar trim but that's the fun stuff (hidden secrets).

@Andyrew - I think I'm going to pause on the steel roof skin work for a bit. Why, you ask? I'm taking a stock roof and a couple other items to the composite mfg I posted about a few months ago.

If costs are "reasonable", I think I'd prefer a composite roof skin. Also, this MAY lead to the availability of some very high quality parts - I'm hoping hoods, trunks and bumpers. I'd have to front the $ for the molds so we'll have to see if it pencils out.

I'll report back on all this, once I know what's what.

Initial location/fit/line up for trimming of the other brace pieces.

Passenger front fit and tacked in, then roof test fit.

The X-brace is fit and tacked in!

I have one area on the underside, rear part of the roof that needs to be trimmed for everything to clear and I'll be ready to final weld this in.

Looking forward to seeing a composite skin on that roof. Structurally it looks amazing.
“Top” work Chris!

Cheers

I'm adding an "end cap" to each of the corner areas of the X-brace. The underside of the roof rolls over and nearly contacts the upper edge of the X-brace so these caps barely protrude above that level and essentially contact the roof, making them a nice surface to which that area of the roof can be bonded. Plus, these nicely tie the ends of the X-brace to the side bars.

Next, I need to get the carbon fiber roof panel and position it on the car. That will allow me to measure and fab these caps for the rest of the X-brace such that they juuuuust contact the under side of the roof and serve as additional bonding surfaces.

This whole fixed roof effort seems to be going to plan, at least so far. But keen eyes will notice the main side bars are still only tacked in. If it all goes south, I can remove the entire structure and run a stock, removable roof set up.

Fingers crossed it doesn't go that way...

Just amazing!

I really hope to see this car in person one day.

@mbseto - If (and it's a pretty big if) my master plan comes to fruition, I'd like to do a cross country tour, stop and meet everyone who's commented on my build and have them sign the underside of the trunk lid.

You all have had some sort of impact on my thinking, planning or execution and I really hope I find a way to honor that.

...assuming I actually finish the dang thing!

Here's the freshly installed front corner cap. Pretty much the same on both sides so I'll spare the server the extra pic...

I have a ways to go on my TIG welding but these won't be visible. So long as they're strong.

And yes, I went back and fully welded the gaps at the corner, just didn't take a pic.

I'll definitely keep an eye out for this!

Dibs if you don't finish it

Some one had to say it. And trust me I understand if it gets to that, but would prefer if you on. It is hard when life gets in the way, and you lose the vision you had for the project.

@914forme Stephen - Not to worry. The "assuming I actually finish..." comment was my attempt to poke fun at myself for how I constantly re-do, change or add more scope to this build.
No loss of vision and nothing really in the way. Well, OK, just me!
Back to it...

Oh please say it's true! I've only commented a few times but I must claim my right to ogle this awesome machine! (Also I'm not so far away, might even be on the way for your road trip)

Since you have the extra roof rigidity have you thought of still making the top removable? Or does having the stock roof bonded on add some extra stiffness?

We could start bidding on the uncompleted project, but the price keeps going up everyday so this could get expensive.

or cheaper as it narrows the focus from people who would not want this sort of thing. The value is only valued by a few. I am sure this would be a short list of us, who would be willing to pony up for such awesomeness as you see in this car.

The downside is that this car crosses lots of other car centric interest areas. Its a custom, its a hotrod, its a Porsche, its a 914, and its a piece of art if your into metal art.

But what I said and I say it again. Chris finish this build, I know how hard it is even when it is the right decision to not finished project can haunt you for years. That being said do this for you, your the only one you need to make happy here. Build it for you, build it because you want to, then drive it and if you hate it, let it go. Experience speaking here.

When I was 14 I picked up a 1965 Jeep CJ-5 that was in pieces out of a guys garage. He bought everything new, including a new Fiberglass body. I spent 2 years rebuilding the Jeep, and when I turned 16 I was able to drive it on the street. I learned to weld and fabricate on this Jeep, I learned to rebuild drive lines brakes, everything. It was mine I put my heart and soul into it. I drove it down the driveway, and onto the street went 1000 feet, turned around in the neighbors driveway and drove it back home, and put it in the garage. It sat for 10 years, and I never drove it, I sold it finally to a friend moving to Colorado, where it lived a great life. And Glad that CJ-5 lived its proper life. But it would not have been sitting in a garage in Ohio.

I decided to work on something that is required to get the car running: radiator hoses!
As mentioned a while back, I'm going to run the hoses under the car in the floor "channels". It proven to work, etc, etc.
That said, I didn't want to use the typical plumber style hose routing clamp, as pictured here. Nothing wrong with them, they just don't appeal to me.
In particular, I didn't like the way they look like they could "unfold" at the 90 degree bend. Yes, I know they are shaped in such a way as to add cross section to combat that, but still.

So, I came up with an idea I thought might work...

First, I fabbed up this prototype (fancy word for "practice piece" ) to zero in on the critical dimensions.

Once I worked out the needed dimensions, I figured I may as well add some style points so it's off to the CAD/plasma system.

Next, using a piece of scrap tube that's happily the same size as the radiator hose, I used the brake to bend the part to this radius, then added a 90-ish for the mounting area.

Here's the part I think works better than the plumbers clamp:
The length I used wraps around far enough that the end is trapped by the ramp in the floor channel. That should serve as a support and help prevent it from unfolding.
At least I think so...

And with the hose in place.
The other thing I like about this "single bolt attachment point" design, as well as the plumber design, is that if I run over anything that grabs the clamp, it's highly likely it would bend open. A fastener on both sides would mean the clamp would have to break/rip or else other areas of the floor would suffer damage.

I'll noodle on this a while and if I convince myself the design "works", it's off to make the rest of them.

Worst case, if the 90 seems too weak, I can weld in a small triangle support at that location. We'll see.

@Tygaboy - Chris if you have the clearance I would dip these in a rubber coating. Plasta-dip or similar to help reduce the possibility to chaff the rubber hose. Or even a rubber pad glued to it after you make it. I know long shot, but it is just the engineer in me saying I see a potential issue.

BTW, I like the style points.

If using pasta-Dip "lol love auto-correct" style coating adding a few holes down each side will help allow it to bond to the part better.

@914forme Stephen - Funny, as I was working with the first one, I thought, "Hmmm, I should dip these in that plier handle liquid stuff..."
Great minds...

And I figured I'd forge ahead into full production!

Looks nice! Curious Chris why you didnt hard mount say a stainless piece of pipe bent to fit?

@Andyrew Andrew - If you mean stainless instead of the Gates rubber hose, I didn't want to risk something that could be crushed closed if I ran over something.
As I understand it, these hoses can take a tremendous amount of abuse before they fail.
Plus, I plan to make and carry a "patch kit": a short length of AL tube, like I made for the radiator hard lines, and a couple suitable hose clamps. If I suffer a cut line, I can cut out the damaged hose, replace it with the AL tube and at least remain drive-able.

So what is the price for a set? LS in waiting

@djway - Hold on, I don't even know if these will work!

But I did go ahead and complete the set I'll be using. Those on each end have been primed.

I find the design most logical

I'm mounting the clamps using Rivnuts and after trial mounting the first clamp, I didn't like the way the top of the Rivnut caused the clamp to sit a tiny bit proud of of the surface of the floor.
So I used a couple of different sized washers as a quick and dirty male/female die set then employed the trusty press to create a depression that just clears the top part of the Rivnut.

The first two done!
And you can see that the left one's "Rivnut clearance dome" is sorta messy. That was the first one I did and the washer set I used created too deep a depression.
So I did the best I could to hammer it back to flat, then gave it a do-over.

Not the prettiest, but as Edd says, "with a lick of paint", it should do just fine.

To quote @bbrock "if anyone says anything about it, I'll call them a dick..."

And best of all, the hose seems well supported so I'm feeling good about this approach. Onward to the rest of them!

And.... done! Well, almost. I'm going to relocate the Rivnut for the upper, left clamp. I wrongly mounted it on the small peak in that area of the floor. The clamps mount noticeably firmer when they are on a full flat.

Anyway, here are things with the front of the hoses connected to the hard lines, too.

I think this clamp design is going to work.

Looking great Chris.

With my current focus seemingly "all things radiator", I went back to thinking about venting. I really don't want to open up the fenders so I figured I'd better prove out the hood vent, one way or the other.

No offense to the approach of "cut the front and sides then bend down the flap to create the vent". I just wanted something different from that so it was back to CAD to see what I could come up with.

The first pic is a piece I made just to get a REALLY rough idea of what things might look like.

The CAD drawing is what I'm going to cut later today. Note the vents remain attached to the frame via those small-ish connections on each side. The vents will be twisted at those points and set to the proper angle.

The small notches at the front edge of the vents is where a piece will fit in that locks them to the desired angle and adds stability.

The whole contraption will attach to the underside of the hood.

Let's see how this works out.

Those hose clamps are next level parts. I dig.

I'll be following your hood mod and radiator install for sure. Every time I look at the holes I cut in my fender wells I cry a little. (I did keep the sheet metal so I could more easily reverse my decision)

@Mueller - Mike, if the hood vent works out, I think it'll be a part I can easily make for others.
Cost of materials and you buy me lunch!