Tudor Chronograph 79160

The Big Block's bulk is a consequence of its engine. In 1976 the automatic Valjoux 7750 replaced the manually wound Valjoux 234 in Tudor's chronographs, adding an hour totalizer and quick-set date, and the taller case of the 9400 series followed from housing an automatic movement. The 79100 series of 1989 kept that machine and changed the surface. Why Tudor made the change is not documented, though collector and dealer descriptions call the differences mostly aesthetic, and the reason the bracelet clasp began to carry the Tudor logo is likewise unrecorded.

Inside the 79160's own run, the dial is the clearest moving part. Collectors call the early dial Mk1: its applied markers have sloping ends and a painted frame surrounds the date window. The later Mk2 has straight markers and no frame. Tudor never published a serial boundary between them, so the early-to-mid 1990s placement is an inference from surviving watches rather than a record. The bezel moves on a separate clock: black aluminum inserts are generally placed after the original plastic, though that cutoff is not established, and fragile originals are often replaced regardless of the watch's age. Tritium dials marked T SWISS T also persist to about 1998, past the end of the 79160, so that marking dates nothing precisely.

Seen together, roughly two decades of Big Block history rest on one movement family and a short list of cosmetic edits. That is why each small difference carries so much weight, and why none of them can be treated as a reliable calendar.

The 9420/0 shows where the 79160 came from, and the 79170 and 79180 show how little separated it from its siblings: in this series the bezel is the principal difference.

The 79160 is risky because so little of its value is in the reference number: a genuine case can carry a replacement dial, bezel, bracelet or movement part, and the plastic bezel and soft case edges make wear easy to hide. Asking prices visible in 2026 run from roughly US$5,000 to 8,000 for ordinary examples to US$12,000 or more for rare or full-set watches, but these are asking figures, not completed sales. For someone who wants a vintage chronograph on a 40 mm wrist and does not mind 15 mm of height, a correct 79160 is a sturdy, wearable watch with a manual-style charm, and the right one rewards patience over a quick buy.