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Discussion Starter · #1 ·
Greetings- need some help here. Switching out my tired 1750 in my 69 Euro Spider (Webers, Euro cooling bypass) for a modified 2 liter I am assembling. All's well until I go to transfer the tach drive from the 1750 (brass drive coming out of bottom of 2-outlet water pump) and discover there is nothing there to drive it on my 1984 2 liter I am building up. The 84 water pump had a blanking plate there (I am assuming electronic tach drive by that time), so did Alfa just delete a drive gear in there?
Can I swap out timing gears if the 1750 had an additional gear to drive tach, or is it a removable (swappable) item? Unfortunately, it looks like I will have to disassemble the front of the engine in hopes of retaining mechanical tach drive.
Thoughts?
1st pic - 1750 tach drive housing with gear visible
2nd pic - 1750 tach drive assembly
3rd pic - no gear visible in partly-assembled 2 liter.
 

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Yes you need to use an older lower crank sprocket/gear with the mechanical type gear on it to accomodate the mechanical cable.
Because you used a newer engine that has the electronic drive.
I had the same issue when I swapped my 1300 Giulia to a 79 spider 2.0L, I had to use the older sprocket/gear to use the mechanical tach, also the 1300 sprocket/gear had a longer shaft on the back because of being smaller block I had to cut that to the same exact size to fit the 2.0L block.
But in your case I think the 1.8L block should be the same length as the 2.0L.
Sorry to hear that you have to take the cover out and all that. Is the engine in the car already?
GOODLUCK!
Giorgio
 

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Discussion Starter · #3 ·
Thanks Giorgio! Luckily, I did not have the engine in the car yet, so it shouldn't be too much hassle. I'll just transplant the lower sprocket over from the 1750 I guess (just hate backtracking after fitting gaskets and tightening!)
 

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I just went through this with an '89 2L. The shaft on the tach drive gear set that I got from an older 2L was about 3/8" too long. My machine shop was able to quickly shorten it to match the shaft of the gear set that came with the newer engine.

Not sure why you'd need to swap water pumps, though.
 

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Discussion Starter · #6 ·
You're right Dean. I encountered that also switching my 1750 timing sprocket into the 1984 2 liter block, and also just had my machine shop shorten the shaft that goes into the bushing in the block to match the 2 liter sprocket that did not have the tach drive end. Not sure what led to this difference (perhaps some change in timing cover depth), but it meant the top and lower sprockets were not lining up with each other. Thanks for reminding me to mention it.
 
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