Question about early vs. late tops Options

[DC_neun_vierzehn]

I know there are two different tops (early vs. late).

My question is can an early top work on a late car IF the rubber seals on the sides have been updated (to match the late windows) AND the bump stops have been swapped (to match the late latches)?

The reason I ask is that I have two spare tops (one early and one late). I have them both stripped down (no rubber, no hardware, no felt headliner, etc.). Just the fiberglass top. And I noticed that the early top much lighter. I weighed them and the early top is approx. 17 pounds whereas the late top is approx. 23 pounds.

I'm not looking to shed weight for performance (although that's a bonus), but a lighter top would be less cumbersome to take off and put on the car.

TIA

-Kris

[930cabman]

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[DC_neun_vierzehn]

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One of the things I’ve loved about 914 World since joining a few years ago is the kind/helpful nature of this community. This reply, not so much.

[SirAndy]

More than you ever wanted to know.
http://www.914world.com/bbs2/index.php?showtopic=73129
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[fixer34]

FWIW, I did the exact opposite to my '70 over 40 years ago. Don't remember why, but I picked up a newer style top with the felt headliner and began using that one. Original top is long gone, probably tossed during a move.
I also replaced the rubber strips along the door sides, but couldn't tell you if they were early or late style.
Top goes on and all latches snap in place. Windows don't go all the way up to seal, but this probably more due to alignment in the doors.

[Robarabian]

That reply was pretty normal actually... someone is watching and eating popcorn to see what the post digs up.... it is a "I am paying attention to your post too" emoji.. the reply poster was not being cheeky with you.. FWIW...

Rob

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One of the things I’ve loved about 914 World since joining a few years ago is the kind/helpful nature of this community. This reply, not so much.

[DC_neun_vierzehn]

More than you ever wanted to know.
http://www.914world.com/bbs2/index.php?showtopic=73129
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Thank you. I’ve read that post a few time before as well as other posts on this topic. I have more questions than answers every time after reading that post, sadly. I’m hoping someone has tried this before and can answer my question yes or no from personal experience.

[JamesM]

While there are changes to the roof itself and the only difference as far as fitment goes is related to the rear rubber block/latches, and those are swappable. As long as you make sure the rear rubber stand offs used match the rear latches used you should be fine.

As illustrated in the posted link the rear blocks have a taller narrower version and a shorter wider version. What isnt shown in that thread is that there are 2 different rear Targa latches that correspond with the different rubber blocks one version is shallower in depth with wider alignment bumps and the other is deeper with the alignment bumps closer together. A mismatch of these components is what causes poor Targa fitment.

[SirAndy]

More than you ever wanted to know.
http://www.914world.com/bbs2/index.php?showtopic=73129
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Thank you. I’ve read that post a few time before as well as other posts on this topic. I have more questions than answers every time after reading that post, sadly. I’m hoping someone has tried this before and can answer my question yes or no from personal experience.

Post #11 in that thread:

"I've got a late top and early windows and it does not seal right at all.
The top should match the windows ..."

Not only are the seals different, the actual mounting points of the seals is different too. So even if you used the seals that are correct for your windows they still won't seal well if used on a top that doesn't match the windows.

And yes, i'm talking about the windows and not the car manufacturing year. Because people can (and do) mismatch doors and windows.

Your top and seals need to match the year of the doors and windows of your car.
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PS: And to make it even more complicated, as explained in that thread linked, '73 is a transition year for the doors and windows. See post #29 in the thread linked.

[JamesM]

Not only are the seals different, the actual mounting points of the seals is different too. So even if you used the seals that are correct for your windows they still won't seal well if used on a top that doesn't match the windows.

And yes, i'm talking about the windows and not the car manufacturing year. Because people can (and do) mismatch doors and windows.

Your top and seals need to match the year of the doors and windows of your car.
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Are you sure about this? Ill have to go compare parts again but...

The front window channel is the same between early and late cars as is the rear window seal so the height of the window should be the same.

Also Porsche superseded the early part with the late and even specified that the late roof to window seals work on the early cars. The rear seal fits differently but the side seals don't. Both these things lead me to believe side seal mismatch is not the issue.

In my experience as long as the rear rubber blocks match the style of rear Targa latches you have, and the window position is adjusted properly, I have not had an issue swapping tops between years.

[SirAndy]

Not only are the seals different, the actual mounting points of the seals is different too. So even if you used the seals that are correct for your windows they still won't seal well if used on a top that doesn't match the windows.

And yes, i'm talking about the windows and not the car manufacturing year. Because people can (and do) mismatch doors and windows.

Your top and seals need to match the year of the doors and windows of your car.
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Are you sure about this? Ill have to go compare parts again but...
The front window channel is the same between early and late cars as is the rear window seal so the height of the window should be the same.
Also Porsche superseded the early part with the late and even specified that the late roof to window seals work on the early cars. The rear seal fits differently but the side seals don't. Both these things lead me to believe side seal mismatch is not the issue.
In my experience as long as the rear rubber blocks match the style of rear Targa latches you have, and the window position is adjusted properly, I have not had an issue swapping tops between years.

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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[cgnj]

@DC_neun_vierzehn I have a 1970 top, a 73 914 with top and a 75 914 with top. I will plop them on 75 and post pics in the next day or so.

[DC_neun_vierzehn]

@DC_neun_vierzehn I have a 1970 top, a 73 914 with top and a 75 914 with top. I will plop them on 75 and post pics in the next day or so.

That would be great, thanks in advance.

Can you also please measure the distance between the side seals on both tops (the distance b/t the slots on the side seals where the door window would roll up into?

@SirAndy has suggested that this distance is different early vs late.

[930cabman]

(IMG:style_emoticons/default/popcorn[1].gif)

One of the things I’ve loved about 914 World since joining a few years ago is the kind/helpful nature of this community. This reply, not so much.

Not all of us have all the answers, but are interested in finding them

[DC_neun_vierzehn]

(IMG:style_emoticons/default/popcorn[1].gif)

One of the things I’ve loved about 914 World since joining a few years ago is the kind/helpful nature of this community. This reply, not so much.

Not all of us have all the answers, but are interested in finding them

My apologies then. When I saw that you had nearly 4,000 posts and posted a popcorn emoji, it felt sarcastic. My bad.

[930cabman]

(IMG:style_emoticons/default/popcorn[1].gif)

One of the things I’ve loved about 914 World since joining a few years ago is the kind/helpful nature of this community. This reply, not so much.

Not all of us have all the answers, but are interested in finding them

My apologies then. When I saw that you had nearly 4,000 posts and posted a popcorn emoji, it felt sarcastic. My bad.

apology not required, but thank you. Like many of us I am a garage cobbler enjoying the hobby.

I have several examples and parts from several sources so having an idea what works with what often gets one in the ball park

[JamesM]

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.

[DC_neun_vierzehn]

I just laid down both naked tops (no hardware, no seals, nothing - just the bare fiberglass. Everything measured the same on the sides - the holes where the screws mounted the rails for the side window seals was identical on both. I'm going to remount the rails to see if those also measure the same.

If they do, then it's just the rubber side window seals and rubber bump stops (and corresponding latches) that materially changed in terms of fitment and therefore they should be able to be swapped if the seals and bump stops (and corresponding latches) were swapped out.

[930cabman]

I just laid down both naked tops (no hardware, no seals, nothing - just the bare fiberglass. Everything measured the same on the sides - the holes where the screws mounted the rails for the side window seals was identical on both. I'm going to remount the rails to see if those also measure the same.

If they do, then it's just the rubber side window seals and rubber bump stops (and corresponding latches) that materially changed in terms of fitment and therefore they should be able to be swapped if the seals and bump stops (and corresponding latches) were swapped out.

Great information, a call to the good DR or 914 Rubber may clear things up

[SirAndy]

I just laid down both naked tops (no hardware, no seals, nothing - just the bare fiberglass. Everything measured the same on the sides - the holes where the screws mounted the rails for the side window seals was identical on both. I'm going to remount the rails to see if those also measure the same.

If they do, then it's just the rubber side window seals and rubber bump stops (and corresponding latches) that materially changed in terms of fitment and therefore they should be able to be swapped if the seals and bump stops (and corresponding latches) were swapped out.

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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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