Cascade Crew

chevymad · Posted: Mon Aug 02, 2010 8:48 pm Post subject: Alternator fan

The alternator fan on my 2nd gen is bending the blades with rpm. I straightened them all out before going racing and they were all bent forwards towards the belt again when I checked today. I think the weight/rpm of the blades is doing it. I've seen some better fan's with a flat plate in front... kind of like an enclosed fan. Anybody have such a thing?

This is the gigantic old school 70s 100amp alternator. Looks like the regular old school alternator but king size. So the fan is larger diameter as well.

aaron_sK · Posted: Mon Aug 02, 2010 9:17 pm Post subject:

The 12si alternators had the better fan, and more output than the standard 10si (although not more than your high-amp one apparently).

I have one sitting on the floor of my Dad's shop. It flips the gen light on for about a second when the car starts, but works well otherwise.

The dimensions should be the same where it counts. Otherwise hit the yard and find a Chebbie with the plastic fan.

chevymad · Posted: Mon Aug 02, 2010 9:39 pm Post subject:

I've got a pile of regular alternators. But the fan's are about 2" smaller then the gigantor 15si unit i've got. I think i've seen the better fan on the newer cadillac units. Think they used this alternator up to 90 models.

chevymad · Posted: Mon Aug 02, 2010 9:46 pm Post subject:

This is the type of fan I'm hoping to find.

http://www.summitracing.com/parts/TFF-7134RC/

aaron_sK · Posted: Mon Aug 02, 2010 9:47 pm Post subject:

There are a couple of pre-Northstar caddies at the local yard. I can poke my head in there real quick sometime later this week maybe.

chevymad · Posted: Mon Aug 02, 2010 10:00 pm Post subject:

Would be awesome. This fan has actually bent forward so far once that its cut up the belt. I put a new belt on saturday morning and straightend the fan. At the time having no idea why it was bent. Today I noticed the blades nearly touching the belt again. Looks like the weight of the flap behind is pulling the blade forward at rpm.

chevymad · Posted: Fri Aug 06, 2010 6:04 pm Post subject:

I picked up a ford fan that might work today. The rebuilders were out of the correct gm one.