You don’t see these too often, and this is the first of its kind in this workshop. As it’s a nice chronograph, you will already have guessed that it belongs to Anders from Norway 😉
The watch doesn’t work, and it feels like the mainspring is broken.
The EP 4-68 movement in all its glory. It has Inca shock protection on the balance, which is nice to have, and has a very smooth reset mechanism.
The bottom plate. The winding/setting mechanism resembles that of some pocket watches, with the see-saw that either engages with the barrel wheel or with the intermediate setting wheel.
Last look before I take the movement apart.
Nice cote de Geneve decoration on the bridges. Note the construction of the fourth wheel with its driving wheel for the chronograph. On most movements, the driving wheel has to be pulled off. Here, the fourth wheel and driving wheel are held by a cock of its own, which means that they don’t have to be pulled apart.
And here it is with the cock removed and taken out of the movement. I like this construction very much!
With the barrel removed, you can see the winding mechanism.
As suspected, the mainspring is broken.
Looks like it was about time for a service 😉
Fresh out of the cleaning machine, and waiting for a new mainspring.
The pushers are rusted through, and will need replacing.
I managed to find a mainspring that is close enough – a 1.25 x .115 x 360 x 10.5 T-End.
Time to put the movement back together.
The winding mechanism goes in, so that I can wind the movement for testing.
The base movement is back together – let’s see how it performs…
Looks like I got the mainspring right. I chose one that was quite a lot thinner than the one that was fitted.
Now I can start on the chronograph.
Anders found two dials, and I chose the middle one, as the original hands will fit. The one on the left has smaller sub-dial, which means that I would have to shorten the sub-dial hands.
That looks rather nice! Look a the font of the numbers – you got to love the 4 and the 7!
Ready to go back to Norway.
Hi Christian- I recently purchased an EP with the EP4 movement inside. Unfortunately, the incabloc setting needs to be replaced in mine, and for the life of me, I cannot find which correct setting (cap jewel, bottom/hole jewel and spring) is right for this movement. Do you happen to know which Incabloc setting would fit? Thank you!
Cousinsuk.com sells inca parts.
Hi Christian- Yes, they do, but do you know what size will fit an EP4?
Hello
I have the same Excelsior Park that you serviced above. I am looking for a dial, my dial is in poor condition. I saw you once found different dials, maybe you can help?
thank you so much
best regards
Jens
I’m afraid it as the client himself that sourced the dial.
I have a Zenith calibre 143, which is the EP calibre 4. It’s in 18kt gold, with a superb dial and unpolished case in excellent condition. The watch is ‘pre-star’ (and without Incabloc), which puts it before 1956, I believe. After servicing, it runs beautifully. Before, however, the return chrono pusher worked perfectly, but was soft (and with no click). Is this normal for the Z143/EP4, please?
By chance, my watchmaker had another 143 for service at the same time, which had a coil spring for the return pusher that wasn’t in mine. So, he made one. I have read elsewhere, however, of other 143s that also have soft pushers (and no click) – indeed, so soft that the return pusher sits deeper in the case than the start/stop one – and that this is a feature of the movement, especially when older. Is this so, please?
A lot of chronograph movements don’t have a return spring on the reset pusher. Nothing wrong with that.
Good! Thank you. 🙂
On two Zenith 143/EP 4 I’ve seen, though, the now-60-year-old return pushers have so little support that they appear shorter than the start/stop pushers, because they have sunk into the case. A watchmaker has suggested that this is a basic design weakness. Certainly, the addition of a spring to the return pusher makes it stand properly and operate well.
Where did you find the replacement main spring? With the lighter mainspring, did you have any issues with the chrono functions?
I bought the mainspring at cousinsuk.com. No, everything worked fine.
I have one excelsior park 1950 cronograph in gold ,
Its working perfect never stopt and keeps time perfectly,
I been looking on internett bit dont find so much info . Is the watch worth something ,,?
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Hi,
By any chance, do you still have pictures of the movement main plate ?
I am try to solve a problem on a EP4 caliber. When the stem is in time-set position, the gears slip and user must maintain upward pressure on the crown to prevent it.
Stem is good and I am suspecting that the stem is loose in the movement mainplate. I would like to see how it is made before fully disassembling it to confirm
Thanks !
Hi there,
The complete set of photos is here: http://watchguy.co.uk/cgi-bin/library?action=show_photos&wat_id=630
Those are all the photos I have.
Best regards,
Christian
Indeed you dont see Expark chronos all too often, but t’s worth noting that Gallet and Girard Perregaux used those great movements…
A stonker.
I was a little worried about the dial change and it would have been nice to see it cleaned and a photo of it so we could have a discussion….
But that new dial really does have a lot going for it…made me smile when I looked at that and as Christian says that font is top.
Thanks for sharing this jewel with us Anders.
I liked the patina of the old dial, was there a reason it was changed?
Really too much corrosion on and under it. When an original NOS dial came up at reasonable money I really did not have to think too long.
Nice work! And what a beauty of a movement.. The NOS black dial looks really cool!!:)
I know nothing of Excelsior Park… is this an in-house movement or something re-branded by them?
That replacement dial is a vast improvement – and very smart!
It’s a company that has specialised on chronograph movements since they began making some excellent movements.
Here is a link with a little history:
http://www.invenitetfecit.com/modeles/excelsior_park_jeanneret_st_imier_en.html
Excelsior Park is one of the old school great designers of chronographs. They held several patents in the development of the modern chronograph, and several other famous brands like Zenith, Girard Perregaux and Gallet used EP movements in some of their watches. A proper “in house” job!