Question about early vs. late tops Options

[JamesM]

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On mine (late top, early doors), i had to modify the seal rail mounts to get the glass to fit against the seal properly.
And that was after adjusting the window angle itself.

And the late seals didn't work either. The extra lip would get stuck on the window.
I had to go back to the early seals without the lip and fine-adjust to get it to seal well-ish.
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I wonder if there are some other variables that got thrown in here? Like an improply repaired/drilled top or something.

In what way did you have to modify the rails?


Also what style rear Targa latches and rubber blocks are you running?

[Literati914]

Not only are the side seals different but the channel mounting points are different because the top of the glass position is different.

Even if you can get the channels to line up, early seals won't seal against late glass and late seals won't seal against early glass.
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Really interested in doing a bit more of a technical deep dive on this as I have not noticed everything you have mentioned to be the case.

As so much bad information has just been parroted on this board over the years id like to nail this down (with data to back it) once and for all.

I'm not saying what is right or wrong at this point just proposing a more in depth root cause investigation. The reason being some of the things you are saying conflict with some of the things I know.

Specifically:

1. Side windows and roofs changed to the newer style sometime in 73 however the later style roof side seal was not implemented until 74. This means that a not insignificant number of cars from the factory got the late roof, late windows, and early seals, and I in fact have one of these cars and its probably the most water tight 914 I have owned.

2. The forward window guide rails (Part# 914 542 013 11 and 914 542 014 11) are the same part for all years. This means the location of the junction between the top/front corner of the window and the Targa, should be the same for all years. Same with rear seal, the upper rear corner of the window should also be in the same location for all years. This should mean the upper edge of the window should be the same for all years (but i will confirm this)

3. The PET may be wrong on this but the side seal attachment strips are listed as the same parts for all years. ( Part#s 914 531 865 10 & 914 531 866 10 )

4. In the factory manual Porsche lists the new side seals ( 914 531 185 10 & 914 531 186 10 ) as superseding the early part and specifies it for use on the early cars.

So, If the seal support rail didn't change, the seals are interchangeable between years as proven by the 73 cars using the early seals and per Porsche themselves in the factory manual, the window depth didn't change (couldn't have as the chassis and window guide didn't change dimensions) then what changed?

Despite not being documented in the PET we know there are 2 versions of the rear rubber supports and 2 versions of the Targa latches that coincide with these blocks. A mismatch here can absolutely cause leakage.

You mentioned the location of the seal mounting strip screws changed. This I have never looked at but doesn't make sense to me as to why it would given the window depth should be the same for all cars. I will verify this though as we currently have 7 tops torn down for refurbishment (both early and late) at PMB, it shouldn't be to hard to verify.

Also worth noting in addition to my 73 car with late roof and early seals, I have a 72 car with 73 doors and an early top, also without issue though on this one I am using the later rear latches and rubber blocks.

Given all this it seems worth a deep dive to figure out why things are/are not working in some cases.

James I'm interested in seeing what you can discover about all this. I purchased the only side targa seals available via 914rubber and I've got gaps (I doubt that's 914rubber's fault, the seals seem like quality parts tbh), that I'm gonna have to go back and address at some point.

I get your point about the vertical window rails not changing, and that sems like a good point but surely the factory changed to taller rubber blocks at the latches for a reason.. or maybe it was the other way around? Anyway, thanks for the effort - looking forward to your report - (IMG:style_emoticons/default/popcorn[1].gif)