Omega Caliber 1164

Brand	Omega
Caliber Number	1164, 1164A
In-House?	No
Based On	ETA/Valjoux 7750
Movement Type	Automatic, self-winding mechanical chronograph
Chronometer Spec?	Yes (COSC Certified)
Lignes	13.25”’
Diameter	30mm
Height	7.9mm
Jewel Count	25 jewels
Beat Rate / Frequency	28,800 bph / 4 Hz
Lift Angle	50 degrees
Power Reserve	44 hours
Hand-Windable?	Yes
Anti-Shock Device	Incabloc
Regulator	ETACHRON
Hand Count	6
Functions	Central hours; central minutes; central chronograph seconds; small seconds subdial at 9:00; 30 minutes chronograph counter at 12:00; 12 hours chronograph counter at 6:00; date at 3:00
Chronograph Layout	6-9-12
Hacking Seconds?	Yes
Finishing	Rhodium plated, damaskeening (stripes)
Country of Manufacture	Switzerland, Swiss made
Known Models	Omega Seamaster Chronograph (Refs: 2599.80.00, 2225.80.00, ST 378.0504, 213.30.42.40.01.001, TB 378.0504, TI 378.0504), Omega Speedmaster Date (Refs: 3211.30.00, 3211.31.00, 323.53.40.40.01.001, 3210.52.00, 323.10.40.40.04.001 (Add your watches to the comments below…)

The Omega caliber 1164 is an automatic chronograph movement found in various Seamaster and Speedmaster watches. This calibre was used starting circa 1992~1993, later to be replaced by watches with the Omega 3304 in the mid to late 2000s.

Base Caliber:

The cal. 1164 is not an in-house movement, nor in-house modified caliber. It is basically an ETA caliber 7750 with custom branding. It appears that the 1164 is produced and assembled by ETA to Omega specs, then cased by Omega.

One thing to note is that the 7750 is a day-date movement in it’s stock form. For the Omega 1164, the day of the week calendar function was removed.

Omega 1164 VS 1154:

The 1164 and previous 1154 are both based on the ETA 7750. The 1164 replaced the 1154 with updated branding and other minor tweaks. For example, the 1154 retained ETA markings under the balance wheel, whereas with the 1164, the ETA markings are not present.

You may see the caliber listed as “1154/1164”, even on Omega’s own website. This indicates a transition, where some pieces may have the 1154 and some may have the 1164. The only way to tell is to open the watch and check the caliber number on the rotor.

Additional Resources:

• Omega 1164 instructions manual (pdf)
• More Omega mentions