[Suri]

Dear Community,

first of all, thank you for letting me join the forum. I’m already reading it for years and it helped me several times. I appreciate that experts take their time to explain problems in detail, in a friendly manner. I hope that you can help me with the following question.

Currently I’m converting and tuning a 2000 Alfetta engine for my GT Junior 1300, from ’73. In the coming weeks I would like to make the custom works to couple the crankshaft, flywheel with the rest of the drivetrain. Currently my car has a hydraulic clutch (I’m not sure if it is original for the year of production). Because it is hard to get a 2000 flywheel, with 6 holes, I’ve decided to turn it. For this, I have received a 1600 flywheel as a sample (but I don’t know if it is for a mechanical or a hydraulic clutch). The plan is to “copy the geometry” of the 1600 clutch, but adding only 6 holes for the bolts of the crankshaft and to press the gear ring from the Alfetta flywheel on the new one. This way, I can have a lightened, custom flywheel. I have also read that there might be some issues also with the trust bearing and I might need an adapter. My questions are the following:

- How do I identify my current 1600 flywheel if it is for mechanical or for hydraulic clutch? (the friction area has an inner diameter of approx. 138,5 mm and an outer diameter of 223 mm, it has 8 holes)
- How do I know if it will work with my current 1300, hydraulic clutch – gearbox bell combination?
- Is it possible that my hydraulic clutch is original?
- Is there a way to identify my gearbox and 5th gear ratio, beside of measuring it, like part numbers, casting properties, etc.
- I have observed 3 additional holes on 1600 flywheel, at the inner edge of the friction area (photo attached). What is the purpose of these?
- If the 1600 flywheel is for a hydraulic version, can I use it as a sample and fabricate my 2000 flywheel? Is it afterwards compatible with the clutch set?
- Do I need a thrust bearing conversion? When is it needed and why?
- Is there another flywheel, maybe from a newer car (155, 164 for instance), which I can take for this project?
- If you generally have some comments on, for example the details which I have to consider or any ideas, I would appreciate them as well

I’m looking forward to hear from you.

Best Regards,
Marcell

 

[hotlegs32]

That is a 1600 flywheel for a mechanical clutch, not hydraulic. Don't use it for this project.
Easiest process is procure a 2000 flywheel with 6 bolts, a standard 2000 clutch, pressure plate and T. O bearing. All that is a direct bolt on. No machining. Have you drilled the crank for a pilot bushing? Or maybe the crank already has a hole for the pilot bushing.
This is a must do.
Post in wanted for a 2000 flywheel. Should not be too hard to find.

 

[Alfar7]

Flywheel

As Karen posted.

If you already have a hydraulic clutch/bell housing the first thing to do is see if your bell housing will fit over the "Alfetta" flywheel/ring gear assembly. (Because the early "1750 bell housings had "indentions" cast inside the bell that interfered with the later larger flywheels & their ring gears. & your`s might be the same bell. The 1600 had small 105 tooth ring gears. The 1750 had 110 tooth ring gears but with the same inside diameter as the 105.

I suggest testing your bell housing over the 130 or 131 tooth ring gear of the Alfetta, as if it does clear, then you only need to use a 2 liter flywheel with the same tooth count as the Alfetta one if you are planning on using that starter.

If your current one has interference, change the bell housing to a later bell housing from a 2 liter.

There are basically 2 types of 2 liter flywheels and ring gears. Those with 130 teeth & those with 131 tooth gears. Each uses a different starter.

On conversions from mouse motors to 2 liter engines where the mechanical clutch release was to be retained then the 2 liter flywheel can be machined to receive a 105 or 110 tooth ring gear which allows use of the original starter,
Adapters exist for using a 2 liter type release bearing for such installations.

 

[Suri]

Dear Community,
Dear Alfar7 and Hotlegs32,

Thank you very much for the answers. It is a good clue to try if the Alfetta flywheel has enough place in the bell housing.

My intention was to use the car as it is now (1300 engine) and swap the engine in 1-2 days in March. So currently I cannot check it with flywheel. I would like to prepare everything as good as I can.

As a plan B, I can ask a friend of mine if he has a 2000 bell housing and buy/make a 2000 flywheel. In this case I’m welly prepared. The advantage of a self-made version is that it could be lighter than the factory one. But I would need a sample for that. My initial tough was to copy the 1600 flywheel geometry but use 6 holes for the crankshaft. But it won’t work, as I understood.

The drilling of the crankshaft will be done in the coming weeks, I already have the bushing.
I would like to learn more in this topic and would glad if you could answer these questions.

Where do you see, if the flywheel is for hydraulic clutch?

How was it, all the 1300 engines in the Giulias had a mechanic clutch or did it change by time?

Do you have experience with newer flywheels, I saw the some 156 and 147 flywheels, they also have 6 holes and as far as I know, the crankshaft from the 155, 164 is compatible with the older 2000 engines, (but larger stroke) and I was wondering if newer flywheels can be used.

Thanks in advance.

Best Regards,
Marcell

 

[Alfar7]

Flywheels

First TOTALLY forget using a 1600 sized flywheel for a template, Clutch components are smaller. To be clear, it won`t work.

I have 2 lightweight 2 liter 131 tooth flywheels on the shelf. 25 lb stock these are 18 lb.