Replacement 7" H4 Halogen headlamps for the original sealed
workshop note (V8NOTE324) contributed in 2005 by Steve Taylor,
who runs the auto electrical supplier SVC at Tamworth in the
West Midlands, provided a useful note on upgrading sealed beam
units so more modern lighting standards can be achieved. The
comments at that time from members pointed to the Cibie replacement
units as the preferred option. Here we have an update.
Upgrading the sealed beam units
Most V8 enthusiasts who still have sealed beam headlights find
the lights wholly inadequate for modern driving conditions.
Steve Taylor, who runs the auto electrical supplier SVC, provides
a useful note on upgrading sealed beams so more modern lighting
standards can be achieved. V8NOTE324
Cibie headlight conversion
David Biddle (Chartreuse 2839) from Buckinghamshire provides
a useful note on his long term experience with the Cibie replacement
round headlamp units. V8NOTE348
Julian Parker provides a most useful 16 minute presentation
on replacement 2-adjuster H4 Halogen headlamps. Video
See details of the replacement 7" H4 headlamp unit and
parts for the 2-adjuster unit. More
See a copy of the full article covered by this webpage.
Photos comparing replacement Cibie H4 Halogen headlamps with
original sealed beams on dipped and main beams. Photos
Checklist of MGB headlamp mounting components, sources
and part numbers produced by Peter Beadle. More
H4 Halogen headlamp unit for a 2-adjuster back shell
The 2-adjuster backshell.
replacement headlamp unit details
Spurrs sought fellow members' views and advice on replacement
headlamps for his original MGBGTV8 sealed beams in a V8BB posting.
An early workshop note (V8NOTE324) contributed in 2005 by Steve
Taylor, who runs the auto electrical supplier SVC at Tamworth
in the West Midlands, provided a useful note on upgrading sealed
beam units so more modern lighting standards can be achieved.
The comments at that time from members pointed to the Cibie
replacement units as the preferred option. Here we have an update.
Victor Smith responded "the main step is to find
a good set of 7" H4 reflector units that can take Halogen
bulbs. Some kits come with flat lenses but probably like me
you will want to have domed lenses similar to the original sealed
beam units. There is a very good 16
minute video video on sealed beam replacement headlamp units
from Holden Vintage & Classic. Julian Parker of Holdens
provides a good guide to the various types of headlamps fitted
to older cars and demonstrates how to replace an original sealed
beam light unit using the available replacements - a budget
unit or the good quality Wipac, Cibie or Lucas units. They take
a 60/55W standard Halogen bulb or you can use Zenon 60/55W bulbs
which produce 90% more light". Fitting HID "burners"
(bulbs) as an upgrade in a standard headlamp unit is both illegal
and an MOT fail.
Chris Bound, who is working on a V8 Conversion using
a very good MGBGT, added "a useful upgrade while you are
working on replacing the headlights would be to add a relay
(or pair or relays) into the circuits. In standard form, the
feed to the lights goes via the main light switch and the headlight
dip switch, both of which can sap the power reaching the lights
themselves. It's a simple modification to insert relay(s) into
the circuits so that you get full power directly from the battery.
There are even handy kits available which contain everything
you need to do the job.
If you are comfortable working on auto-electrics, it's not hard
to make up your own relay circuits. However, whatever your skills,
I think it is probably easiest to buy a complete kit, with all
the wires and terminals made up ready to fit. One of the best
I have seen is available from Moss
Europe at £39.00. I intend to fit the Moss kit to
my car in the near future. They also sell a selection of H4
headlamp units and you can choose whether you want the authentic
Lucas domed lens look (with or without pilot lamps) or the flatter
lenses fitted to later cars. I suspect that you won't want pilot
lights on your 1973 car so these Wipac
items might suit you well. I not certain but I think you may
also need the wiring
harness that comes with the correct plug. As an alternative,
another supplier does a full Lucas conversion kit (part number
is M190) which includes the headlamp bowl, trim and harness
Mike Howlett added "definitely fit relays, not only
because you minimise the voltage drop but because it preserves
your original switches. Clicking on your headlamps puts a 10amp
load across the puny brass contacts in the main switch and the
dip switch. Some sparking must occur and eventually the contacts
will fail - they are 50 years old after all. Using relays means
the switches only have to pass a milliamp load, and the relay
handles the big load. Relays are cheap and easily replaced,
unlike your switches. Chris Hunt Cooke agreed with the
advice to operate the headlamps through a relay system, to reduce
the current passing through the light switch and dip switch,
both to reduce the voltage drop and to preserve those switches.
Mike Howlett added "as for the choice of brand of replacement
headlamp, I originally bought a pair of Wipac Quadoptic units
and was disappointed in the scatter of the beam. Then after
only about 18 months, the reflectors were rusting so I stumped
up extra cash for Cibie Valeo units and have found they
are terrific. The beam control is excellent and even with standard
H4 Halogen bulbs they give better light than my modern VW car.
After over ten years use they still show no sign of deterioration".
Peter Spurrs agreed the Holden video is good, showing
that the job is straightforward. He also agreed on going for
both a good quality replacement headlamp unit and the dome lens
shape. The Cibie replacement headlamp with the side light fitment
is part number 082439.
Bulb upgrade considerations
With regard to bulbs for the replacement headlamp units Peter
Spurrs mentioned the Government website with its guidance on
HID Headlamps" published in May 2010 which says "in
the Department for Transport's view it is not legal to sell
or use after-market HID lighting kits for converting conventional
Halogen headlamps to HID Xenon, but if you want to convert your
vehicle to Xenon HID you must purchase completely new Xenon
HID headlamps. The reason for this is that the existing lens
and reflector are designed around a Halogen filament bulb, working
to very precise tolerances. If a HID "burner" (bulb)
is placed in the replacement headlamp unit designed for Halogen
bulbs, the beam pattern will not be correct, there will be glare
in some places and not enough light in other places within the
beam pattern". The website's advice is clear: "it
is not permitted to convert an existing Halogen headlamp unit
for use with HID bulbs. The entire headlamp unit must be replaced
with one designed and approved for use with HID bulbs".
The H4 Halogen bulb has twin filaments - one for the the main
beam and an offset filament for the dipped beam. The bulbs have
an indent on the locating ring so the bulb can only been fitted
in the correct position to ensure the correct lighting. They
are massively more powerful than the original sealed beam units.
The standard Halogen bulbs are 60/55W. An alternative is a 60/55W
Zenon filled bulb which uses the same current but produces 90%
more light for the same power. When installing Halogen bulbs
take care to avoid touching the glass of the bulb. If a replacement
headlamp unit has a separate provision for a side light then
a 5W BA9 single contact bulb will be needed. When the wiring
connector is plugged in, a large rubber bung is pressed on covering
the terminals at the back of the reflector to provide protection
at the back of the light unit.
There is concern over replacement LED bulbs for headlights because
the LED bulb has multiple light sources so is difficult to focus
in a replacement H4 Halogen headlamp reflector with consequential
concerns over dazzle for oncoming vehicles.
Chris Hunt Cooke highlights the complexity with current
vehicle lighting regulations in the UK by noting that "it
is correct to say that LED bulbs are technically illegal as
the minimum wattage requirements for a headlamp is 30 watts,
which an LED bulb would not consume, but this does not apply
to new cars which have type approval as a unit and so do not
have to conform to those lighting regulations. It is better
to stick with Halogen bulbs for your replacement headlamp units
and if the standard bulbs are not bright enough, then fit the
high performance ones which are now available and promise up
to 150% greater brightness".
found a test review by Auto
Express online which rated the Osram Night Breaker Plus
bulb its top choice (5 stars and 100% score) saying "it's
the beam that secures its win here. It was noticeably bright
with a wide hot spot and a sharp cut-off. A clear victory in
the absence of arch-rival Philips". For those who prefer
to avoid buying via Amazon then their fourth choice Halfords
H4 472 bulb was rated 4 stars and 92% but it seems the price
was a factor in the ranking. Their review said Halfords' "regular
'buy one get one free' winter offer on bulbs wasn't active as
we put together this test, so this pair look very expensive
when compared to rivals. Halfords' H4
472 Alite-branded bulbs actually delivered a better result
than our recommended bulbs by a small margin, but that price
dropped Halfords off the podium. However, they are still worth
considering thanks to the light tunnel performance, which delivered
a win in the maximum brightness test and a 148 FOM rating".
If you have trouble finding replacement headlamp units, Holden
have a large range, as do Demon
Tweeks. For replacement bulbs see Halfords.