The 7" Cibie Bi-Iode assemblies were an upgrade to sealed beam lights that installed directly into the Hella sealed beam housings, replacing the sealed beam unit. The dual bulb, dual reflector Cibie Bi-Iodes, used on the Porsche 911R, 911ST and 911RSR (Ford also used them in the Escort MK1), are perhaps the rarest and most desirable headlights for early Porsches.
Cibie Bi-Iodes, similar to Bosch H1 headlights, used two H1 bulbs, a higher wattage bulb for the high beam and a lower wattage bulb for the low beam.
In addition to being used on the Porsches listed, Cibie Bi-Iodes were also used on the Ford MK1 rally car. It's usually easy to tell by the condition of the lenses where they were originally used as on the Porsches they were mounted behind the Hella lens in front and so had very little wear while on the MK1 there was no protective lens in front and they usually show road wear, such as sand blasting.
Some versions included an extra hole in the large reflector for a city light, a 4 or 5 watt bulb often required in headlights in Europe. Other versions had no provision for a city light.
Here's a picture of a disassembled one. The bottom reflector was attached in an ingenious fashion using a leaf spring (pictured under the large reflector) to provide tension on the small reflector.
The opening for the bulb holders and the bulb holders were covered by rubber, with the shape varying from time to time.
There are at least two versions of lenses and there's a debate as to whether it's Ok to mix and match them. Here's a point of view from automotive lighting expert and AC consultant Daniel Stern:
The 7" Biodes were not homologated for low beam in either LHT (editors note: Stern uses the terminology "LHT for Left Hand Traffic" as he feels it's more accurate than LHD, Left Hand Drive) RHT versions. Also, the hot setup for any kind of a track or road race or rallye car in that era was a LHT lamp on the left side of the car and a RHT lamp on the right, for much better LH and RH curve and bend light on low beam. The non-homologated low beams have very much less height to the nearside upsweep, so even with proper (not artificially low) aim there will not be unsafe or illegal levels of glare or dazzle to other drivers.
Other than early Porsches, Cibie Bi-Iodes were produced for other other marques, including Citroen and Peugeot. These are a bit larger than the assemblies used by Porsche, measuring 190mm in diameter vs. 170mm in diameter. Those are much more common than the 170mm version and much less expensive. Audette Collection has engineered a design enabling them to be installed in the Hella SB19 headlight buckets.
The term H1 actually more correctly refers to a type of halogen bulb, but over time in the Porsche world it has come to stand for the headlamp assemblies made by Bosch that use two H1 bulbs. The following information has been gathered from my experience with these fascinating devices and from informative discussions on the Early 911S Registry and other research - and experience restoring them.Telling the difference between H1’s and H4’s
It’s easy to identify H1’s vs. H4’s when you know what you’re looking for:
History of Bosch H1's
Here are some historic facts in no particular order:
- The first halogen bulb for vehicle headlamp use, the H1, was introduced in 1962 by a European consortium of bulb and headlamp makers.
- Bosch introduced headlights with H1 bulbs in 1966 and headlights with dual filament H4 bulbs in 1971. Strictly speaking that means that H4 headlamps are not correct for SWB cars. Source: Bosch Automotive: A Product History.
- H1’s were first offered as a factory option for the 1968 911S beginning with chassis 11800226 (coupes) and 11850065 (Targas) and additionally for 911T’s and 911E’s starting in 1969 (from posts by Registry members citing Bosch and Porsche publications). They were available as after-market add-ons beginning with their introduction in 1966.
- H1’s didn’t become legal in the U.S. Until 1997 !
- There was one generation, or model, of early H1’s made with city lights in the buckets. These appear to be uncommon.
- The first LHD lenses were marked …007 with raised letters on the outside of the lens and had a larger prism, with two bars on the top of the prism (1966-1969).
- The next generation of LHD lenses were marked …010 with raised letters on the outside of the lens and had a smaller prism with one bar at the top of the prism (1969-1972). There is definitive evidence that the raised script lenses were used at least into 1972. Source: Owner of Porsce Parade Concours Trophy winning 1972 911S.
- The subsequent, and current, generation of LHD lenses are marked …010 with raised letters on the inside of the lens (1973-present)
- H1’s were made for and used on early VW’s. The chrome trim ring has the mounting tab at the 6:00 position and they had the small bulb “city lights”.
- There are two versions of the low beam bulb holders, probably a generational change.