dropping in information gathered over jan 2023 with a set of posts.

subject matter regarding original windscreens (manufacturers and markings) along with original side glass prompted by this thread and question by member tom @TJB/914 .
a really good question.

link to original thread

http://www.914world.com/bbs2/index.php?showtopic=363175

thread ended with summation by @davep - resident expert historian.

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purpose of this thread is to condense the data found and edit out all the meanderings and discussion in original thread which is a bit much to punch through.

this will present the data found in a summarised form to assist anyone if they are interested or require this info for restoration purposes, or if just curious.

many thanks to @JeffBowlsby for his collection of option codes for 914s which goes someway to trying to sort this out - if its sorted out? ---> essential data.
and for asking the right questions along the way.

last of all but not least of all @Vitamin914 for being an expert in windscreen manufacture. the real deal.

comments and corrections very welcome.

the data begins with 1974 model year.

1974 data is simply a first outcome because there was data on file around 1974 1.8 914s from another topic. (see EC-A/EC-B L jet engine research thread in this section).

information concerning other years that grew out of the windscreen and side glass discussion will be posted additionally.

firstly.

1974 windscreens and how to read the engraved text on glass.

with reference to the clarified option listing outlined by dave p.

there were 4 windscreen types found on 1974 cars (examples reasonably trustworthy and original).

2 clear windscreens by two different manufacturers and 2 "tinted" windscreens by the same two manufacturers.

2 side glass types, one clear and one tinted by the same manufacturer.

2 rear window types, one clear and one heated by the same manufacturer.


WINDSCREENS.


1. Manufacturer. Kinonglas gmbh. (brand Kristall). clear.
standard on all 914s (74)

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2. Manufacturer. Kinonglas gmbh (brand Kristall) "tinted" or heat control glass.
optional on all 914s (74).

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3. Manufacturer. Flachglas gmbh (brand Sigla). clear.
standard on all 914s (74).

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4. Manufacturer. Flachglas gmbh (brand Sigla). "tinted". or green glass windscreen.
optional on all 914s (74).

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Note. all the examples of "tinted" windscreens have been linked to CofAs and original sales stickers. the examples of clear have been coupled to clear spec by virtue of elimination. No other examples of windscreen manufacturer or brand have been discovered to date from data compiled.


SIDE GLASS

1. Manufacturer. Flachglas gmbh. (brand Delodur). clear.
standard for all 914s (74).

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2. Manufacturer. Flachglas gmbh. (brand Delodur). tinted.
optional for all 914s (74).

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Note: all examples of "tinted" side glass have been linked to CofAs and original sales stickers.


REAR GLASS.

1. Manufacturer. Flachglas gmbh. (brand Delodur). clear.
standard for all 914s (74).

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2. Manufacturer. Flachglas gmbh. (brand Delodur). heated.
optional for all 914s (74).

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Note: regarding SIGLA windscreens.
on the limited data available all the SIGLA screens were in cars built OCT73-DEC73.
cars from JAN74 on to end of MY 74 were kinonglas screens.
indicating possibly a batching of screen supply by different manufacturers according to date. but-very small data batch to go off. however the SIGLA screens were within a specific date of manufacture time band.



RIGHT HAND SIDE DOOR GLASS/LEFT HAND SIDE DOOR GLASS.
(fixed sections identical etching to openable sections).

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1975-76 CARS

no data was turned up for SIGLA screens in 1975-76.
only kinonglass windscreens.

the revision to the notation on the kinonglass screens is the inclusion of the audi symbol (4 rings) into the car manufacturer logo.
this may not occur at the start of the MY production but further into the model year (as is the case for other revisions in other model years, it does not necessarily co-incide with commencement of model year).
there appears to be slight differences in the D-code line at the bottom of the windscreen information line in terms of layout. one is centred, one is justified to edges.

additionally
the side glass tinted option changes in its notation from F to 1F.
the audi symbol (4 rings) is included with the VW logo.

example 1.
1975 porsche 914 1.8 "tinted" glass option. (screen and side glass).

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example 2
1975 porsche 914 2.0 "tinted" windscreen glass option. (t screen and side glass)

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note this car has a mixture of glass with logos.
windscreen is VW-audi logo.
side glass is VW logo.
vin number is 02519 which is earlier than example 1.
note: side glass manufacturer is different from windscreen manufacturer.
indicates that changeover in glass to a full set with VW-audi logos may not coincide with start of 75 MY or occur at same time with different manufacturers/suppliers.


example 3
1975 porsche 914 2.0 with "tinted" windscreen only option.

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example 4
1976 porsche 914 2.0 "tinted" windscreen.

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example 5
1976 porsche 914 2.0 clear windscreen.

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PRE 1974

example 1
1972 914/4 with "tinted glass" option.
fitted with SIGLA windscreen.
appears identical to 1974 914s with tinted option and sigla screens.

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Note - as minor detail.
Sigla "tinted" screens do not appear to have french approval line in text.
yet the clear screens do. two examples of clear Sigla screens for 1974 have the french approval line included. ??


example 2.
914/6 with kinonglas windscreen. "tinted"

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example 3
1972 914/4 with kinonglas windscreen "tinted"

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example 4
1973 914 2.0 with kinonglas windscreen "tinted"

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example 5
1973 914 1.7 with kinonglas windscreen clear.

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Note - the kinonglas windscreens appear to evolve.
pre 1974 they are noted as plate glass rather than float glass.
this is essentially a technical term which describes a different process to produce the flat sheet glass the laminated windscreens are built up from.
further examples and data is required.
but essentially its the same kind of windscreen as the 1974 kinonglas.
different DOT M-Code certificate numbers and German D-Code numbers are listed.
these are earlier versions of the 1974 screens.
the SIGLA screens appear to be unchanged and on offer or supplied pre 1974.



ADDITIONAL
1970 914/6. thought to be original. kinonglas clear screen.

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1971 914/6. kinonglas clear screen.

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1971 914 1.7. kinonglas clear screen.

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further technical information from member nordfisch.

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what is this one out of? side glass? - but its marked with the porsche logo.

EDIT - based on what i found doing the initial research for 914 glass, this side window cannot be from a 914 (or at least a USA market 914). DOT codes were required in the etched stamp from sept 1968 on.
No dot code. Likely this is 911 side glass pre 1969? or a german market car?
the D number and SEKURIT only text matches pre 69 MY 911s.

as per note above about side glass, there does not appear to be a DOT code included in the etched marking. this would indicate the screen is pre sept. 1968. not from a production 914 (or at least US market). must be from a 911 pre 69 MY? or glass from a german market car?

found highish res photo of dr. f porsche's 914/8

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can just make out the markings enough to see its a kinonglas screen.
wonder if they included the VW logo on it?

porsche museum says silver 74 1.8 is not conveniently accessible at moment to send info on screen markings.

1970 914-6

Should be original windshield

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@gandalf_025

thanks for posting that.
your screen is basically showing that its highly likely that any screen that went into a 914 at the factory contained the DOT # line as required by that time post 1968.


here is a bit more info on kinonglas.
basically a kinonglas screen is manufactured by saint gobain glass.
at the time these screens are being made by Kinonglas who were/are part of the Saint Gobain conglomerate. Kinonglas still exist today under a different trading name.

https://www.vetrotech.com

but have moved out of automotive glass.

apparently they made all the armoured glass vision periscopes etc in tiger tanks!!!!

by 1979 it appears that VW had two suppliers for windscreens and side/rear glass in cars.

1) Flachglass (Sigla -windscreens and Delodur Liz. Sekurit - side and rear)

2) Sudglas (Kristal - windscreens and Sekurit? - side and rear).

some research i did came up with Sudglas being part of the same St. Gobain conglomerate as Kinonglas.

i have seen an example of a 914/6 windscreen with Sudglas branding in black markings.
would possibly indicate that from late 70s into 80s Sudglas may have been making OEM replacement screens for VW-Porsche for the 914.

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VAG suppliers list 1979 showing the glass parts makers.
these are the only two suppliers listed.

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OK; ready to start on windshield polish project for the winter. Don’t want to polish off the Sigla markings as already very faint.
Question: Is the etching on the inside of the glass or the outside? If the latter, have already taped the area.
@wonkipop . ?
@jeffbowlsby ?
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can't speak for sigla, but kinonglas seems to be etched from inside.

if you tape inside and outside you can't go wrong.

@wonkipop
Will try feeling the inside to detect etching. Very faint. Will let you know.
Not planning to polish inside; just the outside.

@wonkipop
The inside is very smooth; the outside is just a tad rough, so:
Presume etching is on the outside, or
Just a bit rough due to nearly 50 years of driving.
So, will polish around the tape over the emblem.

then the etch is on the outside.
which kind of explains why its so faded.

and also explains why the kinonglas ones still look so vivid.
they are definitely etched from inside and not subject to sandblasting in the high speed wind that the classic 1.8 generates at the merest touch of the loud pedal.

of related interest.

screen from 907. manuf sudglas

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Another example collected from BAT sales data.

very late 1974 1.8
k production plate number = 2939517 (wed 17 july 74).
or could be 2339517 (image of k plate at res displayed hard to tell 100%).
06/74 Vin sticker.

sigla screen similar to examples of 1.8s produced during period nov-dec 73.

either a factory installed (highly likely given condition of car - two owner, last owner from 1976-present with car stored off the road from late 79 to 2016).
or a replacement screen dating from the 70s.

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side and rear glass.
914/6 prototype (914114).

marked with P in triangle Porsche part symbol unlike production 914s all marked with VW Logo (including 914/6s). seems to be unique to prototype.

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05/74 914 2.0

sudglas screen.
note imprinted with French Glass certification codes along with USA codes.
lacks VW-Audi logo or porsche P logo.
likely a genuine replacement screen from sometime in the first 10 years after 914 production stopped in 1975. still has white colored etching. later sudglas screens found on some cars is a black marking.

example was from a recent BAT sale.
car was original and one owner car from new.



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