Tudor Big Block 79170

[Fraist]

I was always admiring the Big Block and always wanted one. Unfortunately there was nothing available.
In 2022 I saw a case in the ebay with such a watch and decided to order a case to built one.
The last years i was too busy and all the projects was postponed. This year I believe that I will find the time to finish this project.



The case that I received is fine but still needs modifications to become excellent.
From a first look it needs threaded tube for the crown and the pushers. The existing are pressed inside and low quality.



Also the Plexi that is installed is really crap. Probably from other model that has been shaved inside in order to fit the case.
The lug holes also seems small.



The most difficult in this project is that there is nothing aftermarket available for this watch and any gen part is extremely expensive.
I have ordered and waiting:
Clarks Plexi
Gen tube and crown
Swiss made gaskets
Swiss made 2mm spring bars
Gen 7750 movement

I received also a bracelet 93150 from the seller but I am not able to find 589 endlinks In a reasonable price.
The WSO has aftermarket for 225 $ and the gen are more than 500
Clasp I was thinking a Rafflesdial for the moment


I will update here the built process and hope that i will manage to finish this year the watch.

 

[Singapore9]

Subscribed! Love these! Looking forward to the build!

Can't believe WSO charges that for REP end links; that is madness. Guessing a very low volume item for them? I've had GEN Rolex end links, brand new, for less... albeit, ok, the more common 501b for the 16610.

 

[Fraist]

Subscribed! Love these! Looking forward to the build!

Can't believe WSO charges that for REP end links; that is madness. Guessing a very low volume item for them? I've had GEN Rolex end links, brand new, for less... albeit, ok, the more common 501b for the 16610.

Unfortunately they are so expensive and i am looking around and i don't find any other supplier.

Check the 508 end links that are so small that covers only the half of the watch

 

[Singapore9]

Oh yeah - they're terrible!

 

[Fraist]

Not a lot of free time this period but i manage to have made some small progress.

Received the 7750 and quick install the dial / hands
The dial hour, minutes and subdials hands fitment was perfect. The only problem is the big chrono hand. The opening of the chrono hand was smaller than the pinion. I tested with a spare 2824 seconds hands and the hand fits. So I need a 0.25 mm chrono hand. Probably the one that i have is 0.2.
I have read somewhere in the forum that the clone 7750 takes smaller Chrono hand than the gen 7750.
I ordered some small drills and hope to be able to open the hand and use it.
Nevertheless the movement / chronograph runs smooth and the return of the hands is instant after reset .



I received a gen 704 crown and tube as well as 25-130 plexi. One from Clark and one from an Italian seller In eBay. Both crystalls are the same. And here begins the first serious problem.
The case has a diameter for the crystal 31.75 and the bezel assembly 32.85. That makes a 0.55 gap between case and bezel.
The plexi is 0.825 mm thick. 31.55 internal diameter and 33.20 external diameter.
I am able to press the plexi to the bezel and then the internal diameter of the crystal becomes 31.30 mm.



I think i need to shave the case a bit . Or should i press everything in place as is ???
Does anyone has a idea?
I was thinking to shave the case to 31.45 or 31.55 and then press the plexi inside (0.7 or 0.65 mm gap) .
I believe the gap between case and bezel should be less than the thickness of the plexi to achieve a press fit and water tightness but I am not sure how much Is the optimal.

Back to the built.

The spring bar holes was too small ( 1 mm ). I drilled them precisely with a 1.25 mm drill and now the spring bar fitment is excellent .

 

[Fraist]

Here is the info for the 7750 hands

Guide To 7750 Hand Sizes, Asian, Swiss, New, Old, Hand size

Taken from the RWG2, Posted By Ziggyzumba. Taken with permission and big thanks to Ziggy to allow me to repost his post over here at the Dark Side. Genuine ETA 7750 all variants (all) Hour 2.00mm Minute 1.20mm Center Seconds 0.25mm Subdials 0.17mm Old Asian 7750 version all variants(21,600...

forum.replica-watch.info

I tried a 0.20 drill in my chrono hand and pass through.

So i took a 0.25 and drill and drill carefully the hand .



The drilling was successful and the hand fits perfectly.

 

[asusundevils1971]

Where did you get the dial?. I have a donor watch already with the Valjoux 7750 and would like to make a 79180 to go with my 79160 that was purchased here through M2M.

 

[Fraist]

Where did you get the dial?. I have a donor watch already with the Valjoux 7750 and would like to make a 79180 to go with my 79160 that was purchased here through M2M.

Seller from ebay. Unfortunately he does not have any other dial or case.

 

[Fraist]

Press fitted crown tube and chronograph pushers removed.

The opening for new crown tube is just is diameter for new threads .The openings for the pushers needs further drilling.

I dont have pushers yet. Any recommendation? I need some help !!!

I have found only from cousins but I am not sure for the built quality. https://www.cousinsuk.com/product/rolex-daytona-style-screw-in1

 

[drvintage]

Hey,

the crown tube thread should be M3x0,35 and Pushers M2,5x0,24
Pushers you can take from daytona, 5,5mm: example

Cheers

 

[drvintage]

 

[Fraist]

Hey,

the crown tube thread should be M3x0,35 and Pushers M2,5x0,24
Pushers you can take from daytona, 5,5mm: example

Cheers

Thanks for the link. I just placed an order. I have also ordered one from cousins to check the difference in quality ( it costs 5x more)

The crown that you have is Athaya? If yes then the tap is 3x0.35.
I will install gen tube / crown so I will tap with 3x0.30. Unfortunately the gen tube is not compatible with the 3x0.35.

 

[Fraist]

Nice case. The crystal fits to your case well?
Can you measure the inside diameter of the bezel and the outside diameter of the case and share?

 

[drvintage]

Unfortunately they are so expensive and i am looking around and i don't find any other supplier.

Check the 508 end links that are so small that covers only the half of the watch

You can use the 580 links, these have to be adjusted a little bit. In my opinion this is the best and the only one option to not pay over $200 for wso endlinks, what is nogo.

 

[Fraist]

Looks great.

I will try to bend the 580 as well.