Bulova 11AOAC Movement Series: Precision Automatics with Practical Features

The Bulova 11AOAC movement family stands as a testament to the brand’s ongoing commitment to crafting reliable, practical, and compact automatic calibers for mid-to-late 20th-century wristwatches. These movements—11AOAC, 11AOACB, and 11AOACD—offered watch enthusiasts a blend of mechanical sophistication and daily usability, ideal for elegant yet functional timepieces.

The Core Movement: 11AOAC

At its foundation, the 11AOAC is an automatic mechanical movement designed for compact watches without sacrificing robustness. It was especially prevalent in dress and casual watches during the 1960s and 1970s.

Main Specifications:

• Diameter: ~11.5 ligne (about 25.6 mm)

• Jewels: Typically 17

• Functions: Hours, minutes, center seconds, and date (in most versions)

• Winding: Automatic with manual winding capability

• Beat Rate: 18,000 vibrations per hour (bph)

• Power Reserve: Approximately 40+ hours

• Shock Protection: Incabloc or equivalent

• Calendar: Date at 3 o’clock (base version); day-date in upgraded versions

The 11AOAC was designed to fit slim, elegant wristwatches, but with the mechanical reliability needed for everyday wear.

Variant Overview

11AOAC

• This base version features:

  • Automatic winding

  • Central seconds hand

  • Date display, typically positioned at 3 o’clock

• The date changes gradually near midnight, using a standard non-quickset system.

• Found in many dress watches with clean, understated dials.

11AOACB

• The "B" suffix often denotes technical refinements, including:

  • Enhanced rotor design for better winding efficiency

  • Reinforced bridges or gear train updates

  • Improved date switching reliability

• Retains the same feature set as the base 11AOAC (time + date + central seconds), but with slightly improved durability and serviceability.

11AOACD

• The "D" indicates the addition of a day-date complication:

  • Day and date windows usually appear side-by-side at 3 o’clock.

  • Some models may use bilingual day wheels.

• This version is ideal for users who want a fully functional calendar on their wrist.

• Slightly thicker due to the added day disc, but still compact by modern standards.

Design and Application

Watches fitted with the 11AOAC series movements often included:

• Slim, rounded cases made of stainless steel or gold plate

• Applied baton indices or Roman numerals

• Acrylic domed crystals

• Elegant dress dials in silver, black, or champagne tones

• Luminous hands and markers in some sportier variations

This movement family served in both men’s and unisex models, reflecting the fashion-forward yet practical spirit of Bulova's 1960s–70s catalog.

Servicing and Longevity

Watchmakers view the 11AOAC series as service-friendly, especially for entry-level vintage collectors. Its automatic rotor system, while efficient, benefits from regular lubrication and cleaning.

Servicing Notes:

• The date or day-date switching system should be checked for wear.

• Replace aging mainsprings to improve power reserve.

• Rotor axles must be inspected, as loose rotors can reduce winding efficiency.

• Donor movements and parts are still relatively accessible.

Due to its simplicity and compactness, many vintage Bulova enthusiasts enjoy restoring 11AOAC-based watches as an introduction to mechanical horology.

Collector Appeal

Though not rare, these movements have enduring value because they power many beloved Bulova timepieces. They’re a favorite for those seeking vintage automatic watches that are easy to maintain, pleasant to wear, and historically significant.

Why collectors enjoy the 11AOAC series:

• Bulova brand reliability and availability of parts

• Automatic winding + date/day function in a small package

• Timeless mid-century design appeal

• Affordable and wearable vintage options

Final Thoughts

The Bulova 11AOAC, along with its siblings 11AOACB and 11AOACD, represents a well-balanced blend of style, utility, and mechanical precision. Whether you're a vintage collector, watchmaker, or simply someone who enjoys classic mechanical timepieces, this series offers a dependable movement that continues to tick with purpose and charm decades after its debut.