Correct tonneau stud pattern for 427 cobra

[A-Snake]

Originally Posted by Dcmgt

Variations do exist in these cars. Just look at the example of our friend who recently restored his small block car (never wrecked) to extreme, exactling standards who couldn't find a side curtain to fit one side of his car among several he had, requiring in the end he modify one.

Mike, I think one issue he had on that car was the rechromed ferrules would not accept the posts. Once the 'posts' were sanded down to allow for the thicker chrome they worked.

[A-Snake]

Originally Posted by DanEC

As a simple alignment check - does the rear most ferrule fall in general alignment (longitudnally) with the first lift-a-dot stud on the rear fender?

Thanks

Dan

No, the ferrule is inboard by perhaps 1/2" center to center.

[DMXF]

Originally Posted by A-Snake

Mike, I will add one more element that can affect the fit. Shinkage. I had to have a new tonneau made about 5 years ago because the tonneau that came with my car in 1986 (and fit for several more years) had finally shrunk from non use. Even leaving the old tonneau in the sun on a hot summer day would not relax it enough to again fit the car. The first studs to no longer fit were the outboard studs on the rear cowl.

I hear you Jim, but if all the tops and tonnaus are the same age, you would expect them all to be shrunk, unless perhaps differences in weather exposure between them effected some more than others. I also seem to recall it was one outboard pin that wouldn't line up on some and another outboard one near it would fit (?).

Originally Posted by A-Snake

Mike, I think one issue he had on that car was the rechromed ferrules would not accept the posts. Once the 'posts' were sanded down to allow for the thicker chrome they worked.

If it's the same car I'm referring to, the main issue was not the pins sliding in, but the leading/front edge of the plexi was interfering or overlapping improperly at the windshield frame. This is one of the very few cars that I'm aware of in recent times that was restored using almost all original parts (owner traveled across the country to work out deals getting what he needed), if that gives you a better idea.

[A-Snake]

Originally Posted by Dcmgt

I hear you Jim, but if all the tops and tonnaus are the same age, you would expect them all to be shrunk, unless perhaps differences in weather exposure between them effected some more than others. I also seem to recall it was one outboard pin that wouldn't line up on some and another outboard one near it would fit (?).



If it's the same car I'm referring to, the main issue was not the pins sliding in, but the leading/front edge of the plexi was interfering or overlapping improperly at the windshield frame. This is one of the very few cars that I'm aware of in recent times that was restored using almost all original parts (owner traveled across the country to work out deals getting what he needed), if that gives you a better idea.

They won’t age (shrink) at the same rate if they are regularly mounted (and stored) on the car. It is the non-use that allows them to shrink. This is true for tops also. It’s best to fit the top when warm and store mounted through the winter. When mine shrunk, most of the snaps would fit, it was a couple on each side that would not make it even with the tonneau unzipped.

Yes, we’re talking about the same car. I know the pins were a problem. After asking for some measurements to confirm his side curtains length, he said he found and solved the problem.

[Dan Case]

Originally Posted by ERA Chas

Dan,
Thanks for your evidence about these stud locations. As I said earlier, I am quite surprised that AC took such pains to get these locations consistent. We have seen much evidence that their panel guys had difficulty getting the body locations consistent, left to right and front to rear. This despite hammering aluminum against a wooden buck. The joining of the panels being the critical part.

Dcmgt's evidence about the side curtain fitment on an unmodified car is quite telling.

Fenders were made by one of several suppliers according to the many sources in the UK. Each panel shop no doubt made panels differently and AC had to make them work. Based on old factory images and comments by ex-works people all the body holes including things like demister slots were put near the end using templates. I would think it odd to have more than one template but I can see how hand held templates could get used with less than great care. So were there odd balls, I would imagine yes but I use to play with Boss 302 and 429 Mustangs and they have hand done operations that sometimes got off plan also. I work in a consumer appliance plant and we produce more than a million units a year. Are they all the same, no way, all production operations have "deviations" so don't get too hung up on finding occasional anomalies. When people ask what is typical or normal for cars I can tell them that but I can’t tell them every screw up that no doubt happened. I have worked on Cobras that had holes and the part that was supposed to be in it missing like a carter key hole that never got drilled or a throttle stop that never was installed. Anomalies yes, normal no. Learning what was typical is a totally different subject than covering every possibility that might have or did happened.

The danger in answering anybody’s inquiry in writing is that somebody will have an exception to toss out. I know, I do it too when somebody says such and such was ‘never’ done.

Regarding the ill fitting side curtain. If it is the person and car I am thinking of the confusion was he did not know that the side widow hung over the back end of the door and tucked inside the windshield frame in front. The person I worked with couldn’t understand how a curtain longer than the door could fit the door. I took a series of measurements and photos of CSX2310 and presto the side curtains he had that he thought too long were the correct ones. Case closed.

[DanEC]

Thanks for the sidecurtain ferrule layout.

If you could humor me for one more question on it - is the ferrule layout symetrical on the two doors? I've been corresponding with Bob at ERA on the fact that the ferrule on the rear of my driver door is about 3/8 to 7/16 inch further outboard - the middle one about a 1/4 inch further outboard..

Bob checked several other cars in there shop and verified they were all this way based on the template they use. The layout he sent me is pretty much identical to yours for the passenger door but the driver's door is different. I don't know - maybe just an ERA thing or maybe there is something about the use of a common lower side curtain frame/stud section that results in this when it's flipped around and used for both sides - don't know.

Thanks

Dan

[A-Snake]

Originally Posted by DanEC

Thanks for the sidecurtain ferrule layout.

If you could humor me for one more question on it - is the ferrule layout symetrical on the two doors? I've been corresponding with Bob at ERA on the fact that the ferrule on the rear of my driver door is about 3/8 to 7/16 inch further outboard - the middle one about a 1/4 inch further outboard..

Bob checked several other cars in there shop and verified they were all this way based on the template they use. The layout he sent me is pretty much identical to yours for the passenger door but the driver's door is different. I don't know - maybe just an ERA thing or maybe there is something about the use of a common lower side curtain frame/stud section that results in this when it's flipped around and used for both sides - don't know.

Thanks

Dan

They are symetrical on both doors. By this I mean the rear ferrule is inboard of the first stud on the rear cowl. The ferrule has to be inboard in order for the side curtain to fit against the top.

[DanEC]

That's what I was thinking. I'm going to have to explore this further with ERA I think.

Thanks for your help.

Edit - ERA said their side curtains are not an exact duplicate of originals and the pins have been slightly relocated so they aren't going to match original ferrule locations exactly.

Dan

[DougD]

While we're on this subject, can anyone post a source for original-type side curtains?

Also, what is not included witha Robbins top that needs to be purchased separately?

[mickmate]

Hey Dan, nice job on the measurements thanks for that. I did check your numbers against another original car and they are within 1/16". I did add the dimension in from the edge of the door to the hole center to get a better relative location. I'll see if I can post a diagram when I've drawn it up in CAD. The top and tonneau I just got in have just the vinyl and the snaps. I am sourcing or making the rest, that is roof bows, latches, windsheild split bows, lifta dots, side curtains.

[A98Coupe]

Hey Guys,
Thanks for all the information, but back to my original question which started this thread........nobody has posted any information about the correct stud pattern on the front cowl for a 427 (not a 289, they are different). Can anyone help?

Thanks again
Stuart

[A-Snake]

Originally Posted by A98Coupe

Hey Guys,
Thanks for all the information, but back to my original question which started this thread........nobody has posted any information about the correct stud pattern on the front cowl for a 427 (not a 289, they are different). Can anyone help?

Thanks again
Stuart

These studs as you know are only for the tonneau. Trying to use a reference point on the front cowl might be difficult.
I'd suggest that you lay the tonneau in place, locate the rear lift-a-dot snaps, then pick the 5 spaced out locations on the cowl to place the lift-a-dots studs. Then regardless of the shape of your front cowl you know it will fit.

[Jim Maxwell]

Sorry to not have gotten back to you regarding the pattern. I told you I was slow. I will try to get it done this weekend, although I am working both days.
I have owned 4 Cobras (3-289's and 1-427) and the tonneaus are all interchangeable. How do I know? Because I have done it multiple times. I just grab one when I go out on a road trip and I don't care which one I grab. The windows also have fit every car.
I beg to differ with those that think that the studs were placed and then the lift-a-dots were installed on the tonneau to match. That would be next to impossible to get right.
What does make sense is there was a pattern and the provider of the tonneaus used that pattern to install the lift-a-dots on the tonneaus and the same pattern was used by the guys in the factory for the studs.

Jim

[strictlypersonl]

I tend to think that it was more likely that there was a template for both the body and the tonneau. We have a fiberglass overlay to locate the studs on the body. I would worry that using fabric to locate the studs is too "wishy-washy" to ensure consistency from car to car. The tonneau must end up pretty tight - even a 1/4" variation could effect that.

[Jim Maxwell]

I failed to mention that the soft tops for all the Cobras used these same studs, so the presence of a uniform template used on all the cars is the only reasonable hypothesis. I have three original soft tops, all fit the same.

[A-Snake]

Originally Posted by Jim Maxwell

Sorry to not have gotten back to you regarding the pattern. I told you I was slow. I will try to get it done this weekend, although I am working both days.
I have owned 4 Cobras (3-289's and 1-427) and the tonneaus are all interchangeable. How do I know? Because I have done it multiple times. I just grab one when I go out on a road trip and I don't care which one I grab. The windows also have fit every car.
I beg to differ with those that think that the studs were placed and then the lift-a-dots were installed on the tonneau to match. That would be next to impossible to get right.
What does make sense is there was a pattern and the provider of the tonneaus used that pattern to install the lift-a-dots on the tonneaus and the same pattern was used by the guys in the factory for the studs.

Jim

Jim,
I totally agree that a pattern was used for the body and tonneau when the cars were built. Replacement tops and tonneaus from non OEM manufacturer are produced without the lift-a-dots in place. I've installed lift-a-dots on replacement tonneaus to match the stud pattern on the car. If you want to save a lot of time and grief, buy a punch that is designed to cut the holes for the folding tabs on the lift-a-dots.
http://canvasdealer.com/lift-the-dothandpunch.aspx

[A98Coupe]

Jim,

Thanks again for taking the trouble to make a pattern. I'll await your PM when it's done.

Regards
Stuart

[Rick Parker]

I believe the Robbins products were marked in "White" outline as to where to fasten the Lift A Dots. They made a point that their product is intended for OEM fitting and applications,however as long as the dimensions such as length and width of the interior are very close it will fit.
When I did my Pins and Lift A Dots I took the dimensions from a CSX 427 that was on display at a local classic car dealer. He was kind enough to allow me to take several measurements carefully. They matched the Robbins top very well. I used a cloth measuring tape (used for sewing) and measured from the mirror base to each respective pin, and then made a pattern with square grid pattern paper. It took a complete day to do it right. I used a combination of self tapping pins and some that utilize a metric nylock nut on a threaded shank.

[A-Snake]

Originally Posted by A-Snake

These studs as you know are only for the tonneau. Trying to use a reference point on the front cowl might be difficult.
I'd suggest that you lay the tonneau in place, locate the rear lift-a-dot snaps, then pick the 5 spaced out locations on the cowl to place the lift-a-dots studs. Then regardless of the shape of your front cowl you know it will fit.

Just for clarity I was not suggesting to use a tonneau with lift-a-dot snaps in place to locate all the studs. I was suggesting to fit a new tonneau to the rear studs and then use the tonneau to locate the front cowl studs. Whether you wish 4 studs as used by a 289 or 5 studs as used by a 427.

[Jim Maxwell]

Here are the measurements for the front studs on my original 427 Cobra. You can see that things aren't exactly symmetrical or precise, as others have pointed out. Let me know if you need other measurements.