Zenith 16523

[Ukboweldoc]

Any idea if there is a serial letter(s) that denominate which if these are zenith movement Daytona’s ?

I think it’s for MY 1988-2000 ?

Thanks
Simon

[Haywood_Milton]

There are easy, definitive ways to determine which movement powers an automatic Daytona.

Daytonas with a five figure case number (i.e. 16523) all have the Zenith-based 4030 calibre movement.

Daytonas with six digit case numbers including the additional prefix “1” (i.e. 116523) are all fitted with the in-house Rolex 4130 calibre movement.

The movements can also be identified from the layout of the dial. Watches with the Zenith movement have left and right subdials whose centre posts align on a perfect horizontal with the centre post of the main hand stack. The Rolex 4130 required subdials to be slightly above the equator.

From memory, the Rolex 4130 first appeared in P-series watches.

Haywood

[Ukboweldoc]

There are easy, definitive ways to determine which movement powers an automatic Daytona.

Daytonas with a five figure case number (i.e. 16523) all have the Zenith-based 4030 calibre movement.

Daytonas with six digit case numbers including the additional prefix “1” (i.e. 116523) are all fitted with the in-house Rolex 4130 calibre movement.

The movements can also be identified from the layout of the dial. Watches with the Zenith movement have left and right subdials whose centre posts align on a perfect horizontal with the centre post of the main hand stack. The Rolex 4130 required subdials to be slightly above the equator.

From memory, the Rolex 4130 first appeared in P-series watches.

Haywood

Brilliant, thanks !

[Wallasey Runner]

The 165xx series started in late 1987/early 1988 with the R serials.

The chart below is quite useful...

[Haywood_Milton]

My records suggest that the 165xx series ran from R8xxxxx to P1xxxxx (at least one of that final batch being very special).

I have the 1165xx series starting at P2xxxxx. There does not appear to have been any cross-over of the two models.

Unlike the common practice today, where new models are typically released first in precious metals only, then perhaps bicolour and finally stainless steel in successive years (as per 11661x Submariners and 11671x GMT-Masters), the 4130-calibre 1165xx Daytonas in all metals were introduced simultaneously.

H