The 7-inch sealed-beam headlamp is the period-correct lighting specification for the majority of classic-MG production, the chrome-bumper MGB, the Midget through most of its production years, the MGA, and the various other classic-MG applications where the original equipment was a sealed-beam unit. The sealed-beam construction integrates the bulb, reflector and lens into a single sealed unit that is replaced as a complete assembly rather than as separate components.
For owners restoring cars to original visual specification, the sealed-beam unit is the matched choice.
Sealed-Beam Specifications Stocked
The MGOC sealed-beam range covers the 65/55-watt RHD pattern with integral pilot light, the headline specification, alongside the matched dipped-beam and main-beam variants. The 65/55W rating refers to the main-beam and dipped-beam filament wattages respectively, with the integral pilot light socket carrying a small 4 or 5-watt sidelight bulb that gives the period-correct sidelight appearance without needing a separate side lamp. RHD designation indicates a beam pattern cut for right-hand-drive UK road use, left-hand-drive variants are not stocked under this code.
Sealed-Beam Construction
The sealed-beam headlamp is constructed as a single sealed glass assembly with the filament directly mounted at the focal point of the reflector. There are no separate bulbs to replace, when the filament fails or the unit shows signs of failure, the entire sealed-beam is replaced. The construction is simpler than separate-bulb halogen units, with no opportunity for moisture ingress through bulb seals and no opportunity for filament misalignment from a poorly-seated replacement bulb. The trade-off is that the entire unit must be replaced when the filament fails, rather than just the bulb, but the relatively long service life of a sealed-beam filament (typically several years of regular use) means the replacement frequency is modest.
Tungsten and Halogen Sealed-Beam Specifications
Sealed-beam units are stocked in two principal specifications. Tungsten sealed-beam units use the traditional incandescent filament construction matching the original specification of the classic-MG production years. The beam output is modest by modern standards but the visual appearance is fully period-correct, and the colour temperature of the light (a warm yellowish-white) matches the appearance the cars left the factory with. Halogen sealed-beam units use the same external construction but with an internal halogen-filled glass envelope around the filament, delivering substantially brighter output and a slightly whiter colour temperature while retaining the sealed-beam construction and visual appearance.
The halogen sealed-beam is the appropriate compromise for owners who want period-correct construction with improved lighting performance.
Application Coverage and Fitting
Sealed-beam units fit into the original headlamp buckets on classic-MG cars without modification, the same physical size, the same electrical connections, the same mounting arrangement as the original equipment. Fitting is a 5-minute job per side: remove the chrome rim that secures the headlamp to its bucket, lift out the old sealed-beam, disconnect the electrical plug at the rear, fit the new unit, reconnect the plug, refit the chrome rim. The headlamp aim should be checked after any unit change, the beam pattern on a wall at 25 feet provides a basic indication, with more accurate adjustment using an MOT-standard beam-setter at a workshop. The 7" Halogen Headlamps section (covered separately) is the alternative for owners who want substantially brighter lighting and are happy with the slightly different visual appearance of a separate-bulb halogen unit.
The technical team is available to advise on the right specification for a specific car.