New Build Alternator won't Align!!

[JBraxton]

Hello guys, my dream engine build has been stalled by the dumbest problem I could possibly have, and it's killing me. My alternator doesn't line up with my crank pulley, sits about a half inches further back (away from the flywheel) then the crank pulley. The alternator is not flush against the stand either. Bought the alternator from scat, even went in person after some head scratching to verify I didn't get a freak part, verified the backing plate I was using as well. They didn't know what to tell me. My only thought could be that my crank pulley is to far in, could I have flipped the oil slinger around? Unsure what circumstances could lead to my pulley being to far in. Any advice is much appreciated! Thanks!

[V8Nate]

Is it like your alternator is too long?

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[JBraxton]

It certainly appears to be to long, but scat verified it was the right stock and is "correct".

[V8Nate]

I've had that happen before. I have pushed it back with a pry bar/ screwdriver and tightened the clamp and i have also sanded down the bearing spacer until the pulley almost touched the alternator housing. I think scat has made pulley spacers that you might be able to use on the crank pulley

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[JBraxton]

I wish I could do some small modifications like that, but it's off by so much I hesitate to even try, as I feel something larger has gone wrong. I full half inch is a lot to try and make up through shiming and banging.

[Bruce.m]

Photos please.
A few possble problems. For example an alternator requires a specific stand and the typical dyno version pushes an alternator too far rearward (although you mention its not flush against the stand).

[JBraxton]

Here is a Google drive link, hoping that's allowed, unsure how else to post on mobile. Shows how far off the stand the alternator is,. Thanks! https://photos.app.goo.gl/RMkCLf9abx6AfVws9

[Bruce.m]

The shroud goes to the front of the case lump where the M8 stud is. Cant tell from the photo.

[JBraxton]

Update for anyone experiencing the same issue, unfortunately no easy solution. I scratched my head for weeks verifying the geometry of the tins was correct. Verified that my pulleys don't seem to be adding anything out of the ordinary. Put the largest shim on the crank pulley. Ended up taking the alternator apart, and taking the housing and shaft to velios machine shop in LA where they kindly machined off the extra bits. They did all the critical tolerencing, and I was left to do some non critical clearancing with hand tools. As best as I can tell, it should operate fine now. Everything spins happily in the tins and the pulley lines up perfect now. Still have no idea what I have done to require this. I'm totally fucked if I ever need to replace the alternator. I'll have to hope scat continues to make them and I can swap in the internals. I hate not knowing what the root cause was.

[AdminSteve]

Here is a Google drive link, hoping that's allowed, unsure how else to post on mobile. Shows how far off the stand the alternator is,. Thanks! https://photos.app.goo.gl/RMkCLf9abx6AfVws9

The image you provided is fine, the alternator should not sit all the way back against the stand. We have shims that help with the offset of the alternator pulley/crankshaft pulley alignment. Its not perfect but it should help get them close enough to not pitch the belt while the engine is running. If you had the alternator machined you will never get another to fit without doing the same process all over again unless you identify the underlying problem.

This boils down to tolerances between manufacturing. We dont have tolerance numbers for every item made for these vehicles so what we have is parts that get copied and made to be close. Because of this we have to finesse each and every part we use(some more than others).

AdminSteve