Is this alt fan correct for 837 alternator? I never paid attention to the "ear" until this ad pointed it out.
http://cgi.ebay.com/ebaymotors/1969-Camaro-NOS-Z28-1100837-Alternator-69-427-ZL1-Yenko_W0QQitemZ130170369918QQihZ003QQcategoryZ8073 5QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Boink

Yup, that's correct.

:beers:

That's really odd. You would expect a rotating assembly to be symmetrical. Hmmm, improves airflow?

alan

That's really odd. You would expect a rotating assembly to be symmetrical. Hmmm, improves airflow?

alan
Yeah, and they use the same principal on performance radiator fans.

Don't know about the alt fan, but engine fans of more than four blades are usually asymetical to make them quieter. Evenly spaced blades are more likely to pick up points of resonance, and therefore make odd noises. Can't imagine that the alt fan would move enough air to make noise. But, maybe at higher RPM. But then, seems like there would be so much more noise from other sources that you couldn't tell.

Lynn

Here's my original with the "hook". :thumbsup:

http://img.villagephotos.com/p/2002-2/13522/ZAltFanPulley.JPG

:beers:

John, is your DG pulley silver cad, or gold cad? Do you know which would be correct on an L72?
Thanks

John, is your DG pulley silver cad, or gold cad? Do you know which would be correct on an L72?
Thanks

The pulley is zinc, with just a hint of dichromate wash remaining; L-72 would be the same. :thumbsup:

John,
That's what I have on mine, and I thought it was incorrect, but not positive. ($5 swap met find) Thanks

Do you know the application for a machined gold cad deep groove alt pulley?

John,
That's what I have on mine, and I thought it was incorrect, but not positive. ($5 swap met find) Thanks

Do you know the application for a machined gold cad deep groove alt pulley?

Frequently it's hard to tell the difference between gold cad and a dichromate wash over zinc plating; very few GM parts were ever done in gold cad.

:beers:

I dug my alternator out last night to see if I had a fan with the hook...I don't :( It was a new GM one from Rick's 5-6 years ago. Another item to watch for.
My pulley definitely looks gold cad, not silverish, and carries the part number 3829387 AI Anyone know the application?

I just ran out to verify I have the hook. I do!

The seller of this part lives fairly close to me. He always has rare and expensive parts for sale. I wish I had his source!

The high bidder often buys on ebay if he can find a bargain and then resells.

I think I'm going to peruse the auto parts stores in hopes of finding an alt with the correct fan...might also luck onto the correct pulley! Might have my pulley plated, if the gold cad one I have is nothing special.

Do you just ask to see all the alternators?

I usually ask for Z-28, and normally there's just 1 or 2. These guys know what you are trying to do.....they're car guys, so they don't mind. You want the rebuilt ones, (usually Cardone) not the new ones.

One guy even called his buddy at another store and asked him to check for me.

Not all 69 Z28's got the hook fan, I had this discussion awhile back on here. The fan on my 04C car has a really think blade in that area, but no hook. I bought a replated hook fan and then I found out the one I have on my car is correct too...so now I have both types...and yes, the black paint is not correct, but I did that in the 80's before I knew better:)

Not all 69 Z28's got the hook fan, I had this discussion awhile back on here.

That's interesting. I thought they all had it, but I really dont know for sure.

This one sure doesnt look as though it had been tampered with, and it doesnt have the ear. You wouldnt think the alt fan is something that would be commonly replaced, but it may have been?

837 9B19 (http://i20.photobucket.com/albums/b217/RamAirDave/YellowRSZ/100_3361.jpg)


http://i20.photobucket.com/albums/b217/RamAirDave/YellowRSZ/100_3371.jpg

Dave, that looks original to me. I had several guys on the Yenko board say their cars have this same fan. I don't know if there was particular dates that received this fan or not...I believe it to be original on my 04C car. Someone had replaced the alternator on my car, but it looks like they took the time to take the pulley and fan off of the original alternator.

..... You wouldnt think the alt fan is something that would be commonly replaced, but it may have been?

837 9B19 (http://i20.photobucket.com/albums/b217/RamAirDave/YellowRSZ/100_3361.jpg)




Maybe the rebuild shops thought it cost less to put a new one on to make the alt look like new.

So you think they put a factory looking pulley on too? I think that is pushing it a little...if they go through the trouble to take the pulley off, I bet they took the fan off and reused it too.

I'll check mine against Dave and Jason's pics, but I think that's what my fan looks like.

What's the correct diameter for the deep groove pulley? Also the distance from the centerline of the groove to the back of the pulley.

I know I had an alignment problem with mine, since I was mixing and matching deep groove with standard. My car has A/C and I don't think there is a 3 groove, deep groove crank pulley. At least I could not find a stock looking one, although I guess I could have had one made.

I put washers between the alt bracket and alt ear to move it back until it hit the block.
I ended up taking the alternator apart and modified the bushing to move my alt pulley back that last 1/8" or so.

I've held off on buying one of those expensive 458 DG deep groove smog pump pulleys, as I would expect to have a similar alignment problem.

http://www.camaros.org/pdf/pulleys-PN-2007-02-01.pdf

What's the correct diameter for the deep groove pulley? Also the distance from the centerline of the groove to the back of the pulley.


Diameter; 3 3/16". Centerline to rear flange; 1/2".

Thanks, Fred. Keep that up, and I'll have to stop busting your chops.......nah, too much fun.

Is it possible that Delco had 2 sources or was there a seperation based on early vs late dates?

Another question. I have noticed the flanges on the DG pulleys are not the same thickness. Some have a thicker flange to the inside and some to the outside. Does anyone know about that?

The engineering theory on the fan would be interesting to know.

I'm sure it's about belt alignment, but don't know the circumstances. On my car, I used a standard groove crank pulley, because there were no deep groove, 3 groove ones. Since I had a/c, I needed the three groove, but I had heard that the alternator pulley was the most important one to be deep groove. I had a heck of a time aligning the belt, as the alternator hit the engine. I ended up taking the alternator apart and filing down the bushing to move the las 1/8"