IWC 79240

The 79240 (and derivative 79340 and 79350) is an automatic chronograph movement produced by IWC based on the Valjoux 7750 ebauche since 1998.

Details

The Valjoux 7750 movement was extremely important to the resurgence of IWC and the basic design remains in use today. The company has used it for many important innovations since the 1980's, including a perpetual calendar, rattrapante, and grande complication. The 7750 ebauche was used for the 790 family of movements and the basic architecture is the basis for today's 69000 family of movements.

In 1998, IWC created a novel variant of the 7750 base. Cal. 79240 dispenses with the calendar and most of the chronograph functions of the 7750, leaving only the 30 minute recorder at 12:00 and adding small seconds at 6:00 instead of the usual placement at 9:00. This modification was anything but simple, however. Relocating the running seconds required cutting away part of the movement base plate and adding an all-new bridge with three wheels and a tension spring. Removing the calendar plate required the creation of a new plate to cover the gear train. And this modification did not make the movement thinner; it remains 7.9 mm thick. Like many 7750-derived IWC movements of this period, it features a Triovis regulator rather than the usual Valjoux Fine Regulator.

The movement is gold plated and finished by IWC, which also regulates it. In 2006 IWC began plating the movement in nickel rather than gold, renaming the movement Cal. 79350. This remains in production as of 2019.

Another variant of this movement was created in 2003. Cal. 79340 is similar to Cal. 79350 but lacks running seconds entirely.

Beginning in 2018, IWC is using their in-house Cal. 69355 in new models.

Movement Family

• 79240 (1998-2005) - Small seconds at 6:00
• 79340 (2003) - No small seconds
• 79350 (2006-present) - Nickel plated

Applications

• Cal. 79240
  • IWC Portugieser Chronograph 3714 (1998-2006)
• Cal. 79350
  • IWC Portugieser Chronograph 3714 (2006-present)
  • IWC Ingenieur Chronograph 3725 (2005-2008)

Description: Automatic chronograph movement based on Valjoux 7750 Bi-directional winding Functions: Hours, minutes, chronograph seconds central Small seconds at 6:00 Chronograph 30 minutes at 12:00 Data: Ø 30 mm H 7.9 mm 44 jewels 28,800 A/h Power reserve 44 hours Production period: 1998-Present Successor: IWC 69355