Porsche Headlight Table

[M_deJong]

This is interesting. I’ve never seen a car wired so that both filaments of an H4 would be on at the same time. Seems to me it would overheat the bulb. Makes sense for an H1 though.

I’m a bad person. I have H4’s in my ‘71... for the past 20 years. At least I don’t have the city lights wired in. In my ‘74 I do. For either car they are not original in the US. We were stuck with sugar scoops and sealed beams. So does it really matter?

[Cliff]

Off top of head sure about the clear top rhd you mention.. so maybe was something swapped.

Im being educated as we speak. I did read about & see an early LWB car with clear top H 4’s in the very early 90’s. That was it! So, yes, mine have the early Bosch asymmetric lens’s as on a 67s not the proper RHD type!

[911MRP]

This is interesting. I’ve never seen a car wired so that both filaments of an H4 would be on at the same time. Seems to me it would overheat the bulb. Makes sense for an H1 though.

I’m a bad person. I have H4’s in my ‘71... for the past 20 years. At least I don’t have the city lights wired in. In my ‘74 I do. For either car they are not original in the US. We were stuck with sugar scoops and sealed beams. So does it really matter?

For USA cars it may not matter a jot for reasons you and I touch on but for cars with H4 that were fitted on factory maybe does for folks aiming for authenticity spec or reading what still exists on their car to have a view on what factory parts might have survived. That's where the the subtle things like RHD LHD different part numbers, different date codes stickers that differentiate dates and parts and confirm other more detailed evolutions of H4 on some applications might matter to some owners. After all this forum sweats over hundreds of posts details of all manner of sad anorak authenticity things e.g. font size and machining of fairly generic once inexpensive German spanners a worker once picked up and put in a toolkit that are not even a particularly visible part of the car.... whereas others e.g. the use of the newly invented H4 bulb in headlamps that are different country regulated safety critical / quite prominent externally visible features ...not so much. I suspect my post on detail is seen as irrelevant and anorakish but spanner fonts not. Go figure!

I research these things for my own education and interest and sometimes share here; hard to know why there is inconsistency of careing whether some specification minuteae is authentic gets attention and others seemingly not so important ?.

Maybe info shared from a non USA forum member about a non USA spec lighting is of helpful to some.

[911MRP]

Im being educated as we speak. I did read about & see an early LWB car with clear top H 4’s in the very early 90’s. That was it! So, yes, mine have the early Bosch asymmetric lens’s as on a 67s not the proper RHD type!

Mistype...meant not sure about in above now corrected. By the way clear top was not the early difference I piped up about initially

Always happy to be corrected or learn if folks have more evidence on things I think I know.

[Cliff]

For USA cars it may not matter a jot for reasons you and I touch on but for cars with H4 that were fitted on factory maybe does for folks aiming for authenticity spec or reading what still exists on their car to have a view on what factory parts might have survived. That's where the the subtle things like RHD LHD different part numbers, different date codes stickers that differentiate dates and parts and confirm other more detailed evolutions of H4 on some applications might matter to some owners. After all this forum sweats over hundreds of posts details of all manner of sad anorak authenticity things e.g. font size and machining of fairly generic once inexpensive German spanners a worker once picked up and put in a toolkit that are not even a particularly visible part of the car.... whereas others e.g. the use of the newly invented H4 bulb in headlamps that are different country regulated safety critical / quite prominent externally visible features ...not so much. I suspect my post on detail is seen as irrelevant and anorakish but spanner fonts not. Go figure!

I research these things for my own education and interest and sometimes share here; hard to know why there is inconsistency of careing whether some specification minuteae is authentic gets attention and others seemingly not so important ?.

Maybe info shared from a non USA forum member about a non USA spec lighting is of helpful to some.

Owners prerogative to do as they please but doesn't mean you're not a bad a bad person for your longhood headlight high crimes and other misdemenours

https://drivingintherealworld.com/pa...-daniel-stern/
Daniel has a vast amount of lighting info.
His web site https://www.danielsternlighting.com/

[Arne]

This is interesting. I’ve never seen a car wired so that both filaments of an H4 would be on at the same time. Seems to me it would overheat the bulb. Makes sense for an H1 though.

I agree, seems like a bad idea for a dual filament bulb. But other RoW cars I've owned that used single filament H1s for each beam (mostly BMWs) have kept the low beam lit with the high beam. I really like that system.

I’m a bad person. I have H4’s in my ‘71... for the past 20 years. At least I don’t have the city lights wired in. In my ‘74 I do. For either car they are not original in the US. We were stuck with sugar scoops and sealed beams. So does it really matter?

My early '72 is in the paint shop now, I have a pair of H4s waiting to go in. I did have the city lights wired when I had these lights in my '84, but not in the '72. The H4s will be fine, although I'd prefer H1s just for the cool factor.

[BOYER73S]

Hi John

If I was able to buy a supposed NOS headlight for a 1973, H4 RHD with the Bosche name present but only raised on the inside of the lens not the outside is that an NOS
headlight or a light made much later that 1973?

[911MRP]

I am picking up this old thread rather than starting a new one. At various points in the thread there is mention of H4 with clear top. Not sure I’ve seen these.

I would be interested seeing evidence to support this clear top early H4 assertion .

Previously I provided this image of the announcement that says H4 was new March 72 so we know the date of introduction.



I have a RHD H4 with Bosch code 225 and the period correct white self adhesive sticker with the correct bosch part number for RHD for the back of lamp — which as some will know decodes to May 72. That would make it a pretty early H4 example.

Attachment 556171

It has the pebble top — not clear top.
Pebble top matches my Dec 72 model 73 car and various other cars I know in U.K. are like this.

Not my car but I have permission to use the photo I took of it at Silverstone at he weekend to clarify this point.

To minimise “noise” I am referring only to the proper early H4 for longhood cars (not those with secondary City / parking light) — those with extra bulb are simply not correct for pre-impact bumper even though often fitted to long-hood cars.


I’ve been told H4 never legal for 911 in USA. I understand despite that H4 do often get fitted with little issue from regulators over the pond even if technically they shouldn’t — I take this at face value as it was from folks in USA. I have no first-hand knowledge of the USA market regulations other than seeing the so called sugar scoops on cars from photos back in that period. On this basis seems unlikely USA delivered cars would provide the answer to this particular point.

Maybe we will find there was a very small window March and April 72 clear top H4 before my May 72 example …. or maybe more likely this clear top comment about H4 lens in foregoing and other places is simply incorrect and confusing the issue?

Without some evidence to support clear top early H4
existed back in the day I am strongly leaning to the view that the H4 had pebble tops from the date introduced in Europe from March 72.

Be interesting to see what emerges as solid reference.

Steve

[HughH]

Steve
when i got my car in the early 1990's (aust 73 built in July 73) it had one clear one and one pebble one - both a bit foggy and sandblasted
Not knowing any better I replaced them with new ones

Since them i have observed very original early cars with clear topped lenses (obviously RHD) My memory however is that they are earlier cars - maybe 1970 / 71 rather than 73's or 72's
given that lenses are almost disposable "maintenance items" over here due to breakage from stones on country roads apart from any other sort of accident I have no way of knowing if either was original to my car. But they certainly existed for cars built in the early 70's and were on H4 lights here - rightly or wrongly

[911MRP]

Hi Hugh

It wil be interesting to see if any clear top H4 marked get posted.

There are similar looks clear lens top but not convinced they are H4 of type from March 72 onwards. I was recently all over a 20 k from new model 73 unmolested car all sorts of checking for 5 hours including removing the headlights to see the white sticker and to check the product code and Bosch date code — it had pebble tops. Like the ones I pictured above. Both lamps were date of car build minus month. An H4 clear top with date and product code corresponding to my Bosch references would convince me especially so if attached to a known provenance car. Until I then maybe these being ascribed H4 clear are something from earlier period?

To your point below is a RHD Bosch lens from a 1971 911 that has clear top but it precedes introduction of H4 per the technical information : clear top significantly it is not marked H4. I think this is type being wrongly ascribed to early H4 clear top because of superficial similarity ….


Above is the front of my date coded 225 May 1972 which according to the tech information is soon after the H4 introduction (it matches the pair in my December 72 build RHD) as well as a number of other RHD cars I believe have (at least one) original H4 lens. Note this one has H4 marking and pebble top.

If a Bosch example emerges as evidence with clear top and marked H4 maybe I will believe it but until then I suspect it is a case of mistaken identity. As you say possible ( probable even ) the incorrect older dealer stock clear top / non H4 lens got fitted incorrectly to replace a broken H4 back in time especially if the then new H4 replacements hadn’t arrived. Thereby leading to this confusion.

Possibly different LHD but doubt design not same as RHD other than being handed

I suspect this early clear top/ H4 myth will be busted. Let’s see

Steve