Finally.....The Correct Size Alternator Pulley

[Dynomite]

The Correct Size Alternator Pulley is about 2.75 inch OD on the face....This ALL Aluminum Pulley is very light and just a tad larger yet very close to 2.75 inches diameter. It is a little Pricey from Summit Racing. The Installation is very easy with my 15/16 inch modified Open End Wrench and 5/16 Allen Wrench.

The Stock Alternator Pulley is the Black Pulley on TOP and the Black Pulley to the Left (in right photo).
The MCH-208 is the same Diameter as the Stock Pulley.........The MCH-208 has identical Offset as the Stock Pulley.
Actually the MCH-208 is just a tad larger diameter................The Stock Pulley uses a separate thick offset washer.



This Pulley can be installed without removing anything including the Serpentine Belt (except the Original Alternator Pulley).
Look for MCH 208 on Summit Racing MCH-208 or Ebay MCH-208



Oh.....by the way.....I just invented a New Way to install the Serpentine Belt......Remove the Alternator Pulley (takes 1 minute) and position NEW Alternator Pulley inside Serpentine Belt and lift up the Alternator Pulley and Serpentine Belt with Belt Tensioner compressed (Keep Serpentine Belt aligned with Belt Tensioner Pulley). Now just slip the Alternator Pulley onto the shaft (very easy to do and plenty of play) and tighten up the 15/16 inch Alternator Pulley Nut.

Lastly......install the Aluminum Alternator Pulley Cap with the three Allen Head Bolts provided with just a little torque as they are threaded into Aluminum.

If you look closely, you will notice also my ALL Aluminum Belt Tensioner Pulley.



See All Aluminum Alternator Pulley

[secondchance]

How about that! I had to have the back machined for correct offset. Seems you found one with correct offset. Congrats!

[Dynomite]

Great Minds Think Alike

Yes......just checked the offset of the MCH-208 and appears perfect.
It sure ran nice and smooth

Originally Posted by secondchance

How about that! I had to have the back machined for correct offset. Seems you found one with correct offset. Congrats!

[Roadster]

Received my spare 200A alternator yesterday. Pulley may be a tad small with my unscientific measurements...lol I am guessing it is between 60-62mm. If and when it needs replacement, can always swap out the original pulley if needed.

[Dynomite]

Actually you can run an under drive or over drive pulley with the right length serpentine belt. But I am finding 2.75 inch (as you measure on the face of the pulley) is correct diameter and 2-7/8 even a tad better as it opens the tensioner just a tad more. I have some more of the MCH-208 on the way and will provide more photos in original post using my modified 15/16 inch Box Wrench and 5/16 inch Allen Wrench shortly.

Your pulley looks more like 2-3/8 inch diameter on the face of the pulley.

Originally Posted by Roadster

Received my spare 200A alternator yesterday. Pulley may be a tad small with my unscientific measurements...lol I am guessing it is between 60-62mm. If and when it needs replacement, can always swap out the original pulley if needed.

[Roadster]

Originally Posted by Dynomite

Actually you can run an under drive or over drive pulley with the right length serpentine belt. But I am finding 2.75 inch (as you measure on the face of the pulley) is correct length and 2-7/8 even a tad better as it opens the tensioner just a tad more.

Thanks for the pulley tip Cliff. I also do have a spare serpentine belt. But hopefully won't have to worry about that soon, as one of the PO's had that replaced back in 2010 along with getting the belt tensioner rebuilt at that time. And its only been 12,000 miles or so that have been accumulated since then. I was lucky to get about 10 pages of service records from the Chevy dealer that did all of the work on the Z.
But you never know, always better to be prepared to an extent, rather than not!!!

[Dynomite]

Originally Posted by secondchance

How about that! I had to have the back machined for correct offset. Seems you found one with correct offset. Congrats!

This Pulley can be installed without removing anything including the Serpentine Belt (except the Original Alternator Pulley).
Look for MCH 208 on Summit Racing MCH-208 or Ebay MCH-208


The MCH-208 is the same Diameter as the Stock Pulley. Actually the MCH-208 is just a tad larger diameter.
Use a 1/2 inch Adapter on Socket Wrench to Unload the Belt Tensioner when removing/installing Pulleys.


The Offset of the MCH-208 is identical to the Stock Pulley.
The Stock Pulley has a removable Offset Collar.


See All Aluminum Alternator Pulley

[Roadster]

I just might have to order that MCH-208 pulley after all and have it all ready for the replacement unit whenever it may be needed......

[Dynomite]

Originally Posted by Roadster

I just might have to order that MCH-208 pulley after all and have it all ready for the replacement unit whenever it may be needed......

Do NOT install the Pulley onto the Alternator on the Bench tightly as you want to make the final installation of that Alternator Pulley once the Alternator is Installed on the ZR-1.

This Pulley can be installed without removing anything including the Serpentine Belt (except the Original Alternator Pulley).
Remove the Alternator Pulley (takes 1 minute) and position NEW Alternator Pulley inside Serpentine Belt and lift up the Alternator Pulley and Serpentine Belt with Belt Tensioner compressed (Keep Serpentine Belt aligned with Belt Tensioner Pulley). Now just slip the Alternator Pulley onto the shaft (very easy to do and plenty of play) and tighten up the 15/16 inch Alternator Pulley Nut.

Lastly......install the Aluminum Alternator Pulley Cap with the three Allen Head Bolts provided with just a little torque as they are threaded into Aluminum.

The MCH-208 is the same Diameter as the Stock Pulley. Actually the MCH-208 is just a tad larger diameter.
Use a 1/2 inch Adapter on Socket Wrench to Unload the Belt Tensioner when removing/installing Pulleys.


The Offset of the MCH-208 is identical to the Stock Pulley.
The Stock Pulley has a removable Offset Collar which is NOT used in the installation of the Aluminum Pulley.


See All Aluminum Alternator Pulley

[secondchance]

Originally Posted by Dynomite

The Offset of the MCH-208 is identical to the Stock Pulley.
The Stock Pulley has a removable Offset Collar which is NOT used in the installation of the Aluminum Pulley.


See All Aluminum Alternator Pulley

This is odd/interesting. What year is the alternator for? For 94 Z OEM pulley does not have the spacer/collar you are showing. I had to have the billet pulley machined to mimic OEM pulley shown with dished back.