Im looking for a Double V Belt alt pulley that will fit the FD alternator anybody know of one? or should the FC ones fit right on it?

 

The FD shaft is larger than the FC's, so the FC pulley will fit if it's bored out a bit.

 

Banzai sells exactly what you need. I purchased line from them. Great customer service too!

 

Fc alt pulley has a 15mm shaft..the FD alt takes a 17mm bore.

 

+1 for Banzai and/or boring it out. Both are simple and easy

 

Im trying not to bore one out is the thing but the banzai one i wouldnt have to?

 

Mazdatrix is your friend. Pulleys

 

Hmm pretty much just assumed mazdatrix would be overpriced but wow these are actually pretty good.

 

From what I've read, they are about the best plug and play option there is for using an FD Alternator in any earlier version Wankle car.

 

Just to add some "useless info".
If you switch to a Ford Taurus 130 amp alternator it will take the same FD Sized alt pulley(17mm bore)

 

+1 for this info. Actually, I'd like to add some of what I call the "Hidden Hacker Info"

It was around 1989 or so when Japanese car alternator manufacturers (Mitsubishi and Denso) finally joined the rest of the world in using a 17mm shaft on their products. Even the second gen Corvettes from the early 60s have a 17mm alternator shaft! Prior to this, Mitsubishi & Denso used the 15mm shafts as found on our FC alternators until existing applications (such as the FC) were out of production. Afterwards, everything got a 17mm shaft. The JC Cosmo's alternator is such an example of this change.

Bit of advice for the uninitiated:
The pulleys from Mazdatrix are aluminum and warp like the Enterprise if anything goes wrong, such as the pulley nut coming loose. I learned this the hard way, due to a change in thread pitch between 93 and 94 Taurus/Windstar Alternators that I was not aware of. One nut looked damaged on the corners, so I substituted the other one. It went on fine, felt fine but popped loose (not off) a few blocks away. By the time I got home, the pulley was out of round and wobbled front to back by 2mm when spun. Took some prying to get it loose because the hole had shrunk slightly and wasn't round anymore either. Don't ask how, this made no sense to me either and I wasn't in the proper frame of mind to approach it scientifically at the time.

I got lucky and found a dual V-belt pulley at Jegs that fit the Taurus Alt. Rear belt track is spaced the same as the Mazdatrix one, but since the front one is about 2mm too far forward, you can't use dual belts. For being $15 and available right down the street, I'm quite pleased with the results.

 

Sounds like all you were missing with the Mazdatrix pulley was a little bit of Lock Tite.

I have a buddy of mine who has been running his for 4 years and still going strong.