About to take delivery

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Dieselman
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Re: About to take delivery

Post by Dieselman » Thu Dec 28, 2017 11:26 am

xmexclusive wrote: I examined 7 dip beam reflectors and none showed any sign of heat damage to the silvering or evidence of oxidation.
Six were from Mk 2 lamps and one Mk 1 lamp.
Settled dust was a factor from long service.
Similarly dust was the only factor on the main beam reflectors.
I remain certain that reflector heat damage is not an issue with XM headlamp reflectors.
I have a selection of series 1 lamp units and have definitely experienced heat damage to a number of the reflectors. The heat damage is evident by the silvering becoming cloudy and brittle.
Series 1 lamp units also suffer severe reflector oxidysation if not in use, or dry storage.

Maybe series 2 units don't suffer this.

I think a good solution would be to use reflectors from another modern model of car. I think Laguna mk1 and Mk2 units would fit into XM lamp units well and possibly Volvo V40. These would alleviate the need for any lens as the reflectors are genuine complex parabolas, focussing the light without any further requirement.
1992 3.0 V6-24.Rp 5713 EXY Black
1992 2.1SD M.RP 5685 in ENT Blue Sideral
Previous:
1990 2.1SD M.RP 5049 in EJV Mandarin
1992 2.1SD A.RP 5698 in EJV Mandarin
1994 2.1SD A.RP 6218 in ERT Triton Green
1991 2.0SI M.RP 5187 in EWT White

xmexclusive
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Re: About to take delivery

Post by xmexclusive » Thu Dec 28, 2017 12:18 pm

Hi Dean

The XM units were designed by Valeo to Citroen specification.
They were the first use of complex surface reflectors for headlights.
The dip beam design achieved the retention of all output to within then French regulations limiting pattern.
It was claimed to light this area better than any previous design.
That means no scatter and does not claim full and even coverage, just the best that had been achieved at that time.
Valeo and Citroen state that:-
"The output and efficiency of headlamps is determined by the manufacturing quality, shape and above all, the size of their reflectors".
They accept that round reflectors are the best option and easiest to manufacture.
However in response to the demands of stylists and aerodynamicists car body shapes took precedent.
Their spec revolved mainly around the already fixed body shape and therefore available lamp slot.
The glass rake angle was a major design constraint as optically a 20% slope absorbs 12% of light output.
They also note:-
"Today, when most headlamps are of varying shapes, one rarely sees the old round type.
However these different shaped lights have inferior performance to round parabolic ones".

Valeo will have designed the Rover lights to UK dip spec and specified size and shape.
With previous experience from the XM design I am not surprised they achieved better with a later design.
The body shape spec may well have been less demanding and Valeo a bit more vocal to get that better result.

There are a number of possible options for upgrade.
Most that have been tried so far do not meet either output or compliance requirements.
For UK approval the complete modified unit and bulbs must be approved by test in the vehicle it is to be used in.
I find this a very difficult hurdle in the way.
My personal solution is based on new and refurbished Mk 2 standard units.

John

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White Exec
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Re: About to take delivery

Post by White Exec » Thu Dec 28, 2017 2:17 pm

Room for one of these inside the dip-beam enclosure?
http://www.myhellalights.com/index.php/ ... -headlamp/
The unit is H4 ECE, so will be capable of proper dip pattern (main beam too).
Hella halogen units are outstanding in quality, I remember.
Anyone's guess what the additional XM front glass will do.
Chris
1996 XM 2.5TD Exclusive RP7165 Polar White
2003 RAV4 D4D 2.0 5dr LHD Silver WORKHORSE
1989 BX19RD Delage Red Deceased; 1998 ZX 1.9D Avantage auto Triton Green Company car 1998-2001; 2001 Xantia 1.8i auto Wicked Red Company car 2001-2003

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russ92xmsed
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Re: About to take delivery

Post by russ92xmsed » Thu Dec 28, 2017 2:40 pm

Dieselman wrote:
I think a good solution would be to use reflectors from another modern model of car. I think Laguna mk1 and Mk2 units would fit into XM lamp units well and possibly Volvo V40. These would alleviate the need for any lens as the reflectors are genuine complex parabolas, focussing the light without any further requirement.

Interesting thought. What about Vauxhall Calibra. They were very narrow headlights. Or Peugeot 406 or even 306.

I'd be very interested to see Rays conversion.
Russ

1992 K reg XM 2.1 Auto SED RP 5712
1992 K reg XM 2.1 Auto SED RP 5705 (D)
Also
2003 C5 2.2 HDI Exclusive

I sell Engine bay, 1990 COTY, Total & Club XM Sticker Decals
http://www.rjwcreativedesign.co.uk

Dieselman
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Re: About to take delivery

Post by Dieselman » Thu Dec 28, 2017 4:15 pm

I think for OEM replacement lights from Hella, these would be better than sealed beam lights. http://www.myhellalights.com/index.php/ ... dule-gen2/" onclick="window.open(this.href);return false;

The downside to all projector type lamps is the light passes through a thcick glass lens, which will always reduce output, hence I think a modern reflector lamp is a better idea, as all teh light is reflected forwards.
1992 3.0 V6-24.Rp 5713 EXY Black
1992 2.1SD M.RP 5685 in ENT Blue Sideral
Previous:
1990 2.1SD M.RP 5049 in EJV Mandarin
1992 2.1SD A.RP 5698 in EJV Mandarin
1994 2.1SD A.RP 6218 in ERT Triton Green
1991 2.0SI M.RP 5187 in EWT White

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White Exec
Citroen God!
Posts: 4563
Joined: Fri Mar 11, 2011 7:38 pm
Orga / RP numbers: RP7165
1996 2.5TD saloon, manual, Polar White
Location: ex-Ealing, Cheshire, W.Sussex & Surrey. Now living in Sayalonga (Malaga, Spain)

Re: About to take delivery

Post by White Exec » Thu Dec 28, 2017 5:11 pm

The Hella units I suggested above are not sealed beam units, but metal reflector/glass front/H4 units designed to replace sealed beam with much more efficient halogen. I used the round versions numerous times to replace OE 7" and 5.75" sealed beam on Rover P6, Dolomite, 1300 and Mini. Output and coverage was first class on both beams.
Chris
1996 XM 2.5TD Exclusive RP7165 Polar White
2003 RAV4 D4D 2.0 5dr LHD Silver WORKHORSE
1989 BX19RD Delage Red Deceased; 1998 ZX 1.9D Avantage auto Triton Green Company car 1998-2001; 2001 Xantia 1.8i auto Wicked Red Company car 2001-2003

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djg
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Re: About to take delivery

Post by djg » Thu Dec 28, 2017 5:40 pm

Those 90 mm modules are really nice, there are even versions without the high beam. I never disassembled our headlamps (having the benefit of Mk2 and LHD, I never really needed to do so) but those of you who did, is something like this feasible? Do these come to replace the usual units from behind, fitting-wise?
Bye,
Gábor

1996 XM 2.5 Turbo D VSX (LHD, Bleu Mauritius)
1986 BX 19 TRI Break (LHD, Rouge Vallelunga) deceased

xmexclusive
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Re: About to take delivery

Post by xmexclusive » Thu Dec 28, 2017 6:31 pm

The XM dip reflector is a separate part, it screws in with 4 screws.
Mounting holes are 150mm lateral by 65mm vertical.
That Hella unit only specifies the lateral fixing holes at 143mm.
I estimated the vertical fixing holes at 72mm apart vertically.
The opening for the XM dip front reflector is 150 lateral by 70mm vertical.
The Hella unit will be a very tight fit vertically in the XM outer case probably preventing beam adjustment.

John

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