Alternator Fan

[Timothy B.]

Can anyone help me ID this alternator fan. I suspect 1967 and newer but I thought I would ask. Note the part # on the back along with directional arrow..

Thanks in advance, Tim

[David L.]

Re: Alternator Fan

Tim,

I know that I have 2 or 3 these fans in my collection. The "8161" stamping is not a GM part number or even a partial GM part number, maybe a vendor part number. My educated guess is that that your fan may be GM part # 1966990 (11 blades, 5 3/8" O.D.) but I would not bet the farm on it. I'm sure someone in the NCRS must have a NOS 1966990 fan for comparison. I might even have one. When I get a chance I will check my collection.
The 800594 fan is similar but I believe it has only 10 blades. GM # 1966990 was replaced with GM # 800594 in Jan. 1971 as per Chevrolet Parts History.

Dave

[Timothy B.]

Re: Alternator Fan

Thanks Dave,

This fan also looks like some of the Mr Gasket and other aftermarket fans..

[Wayne M.]

Re: Alternator Fan

Can anyone help me ID this alternator fan. I suspect 1967 and newer but I thought I would ask. Note the part # on the back along with directional arrow..

Tim -- here's a long shot; I see that my Oct '66 thru July '69 P&A30s, Gr 2.274 "Pulley, Fan, Spacer" has a family of part #s (3888186, 3888168, 3888184) which are all alternator pulleys, without fans.

Maybe your number are the last 4 digits of the fan that is designed to go with the pulley #'s above.

[Timothy B.]

Re: Alternator Fan

Very interesting Wayne, that's why I asked the question here.

I also have what I believe to be a 1963 A/C fan, baffle, and pulley that I will post a picture for others to comment on.

[David L.]

Re: Alternator Fan

Tim,

Enclosed is a photo of a NOS 1949355 pulley in a Delco Remy "string" box that is correct for a 1963 Corvettes w/AC. In my 64 Chevrolet Parts Catalog (effective Oct. 1963) it is described as 2 1/2" O.D., 21/32" shaft dia., and 1/2" width. The pulley is not in my 1963 parts catalog (Oct. 1962) because the C60 option was added later in the 63 Corvette production. The pulley is stamped with the number "5" (last digit of part #), measures 2.67" in dia., and 0.75" wide. The 2 1/2" dia. is the measurement when a fan belt (1/2" wide) is wrapped around the pulley.

The correct fan is GM # 1940994 (13 blades). I have some in my garage attic.

I do not have the baffle, GM # 1877887.

Dave

[Timothy B.]

Re: Alternator Fan

David,

Thanks for those pictures, please look at what I have as I believe this is the correct arrangement for the A/C set up.

I am not sure if the fan is the same as generator equiped cars from the era and I am not sure where I got the fan. The pulley does not have a keyway groove like your picture shows but the measurements are the same. Also, the baffle I picked out of a pile from a friend that's been the business for a long time, it looks correct to me.

[David L.]

Re: Alternator Fan

Tim,

Your pulley has the number "5" and is GM #1949355 with or without the key way groove. I have other NOS "stamped steel" alternator pulleys as follows:
1949356, 2 7/16", stamped "6"
1949357, 2 5/8", stamped "7"
1949358, 2 7/8", stamped "8"
The pattern is obvious.

The 63 Corvette alternator pulley (base engine without A.C.) is "solid steel" w/offset, 2 7/8" dia., about 1" thick. The GM part # is 1958095. This pulley was used on the 63 Corvette (base) and 63-65 Chev. Ser.10-30 6cyl. trucks. I have collected several of these pulleys from 63-65 Chevy junk yard trucks back in the 1980's with original 1963-1965 alternators, some have the key way slot, some do not. A key was never used in these applications, therefore, the key way slot is useless.

I believe your baffle is correct. I might have one, I would have to check.

Your 13 blade fan is also correct, GM # 1940994. I have many used and at least one NOS 1940994 fan.

Dave

[Gerard F.]

Re: Alternator Fan

Tim,

A 67 base engine Alternator fan was gray phosphated.

Here's mine:

Cleaned up:





Being Gray Phosphated:





Just having fun,

Crockpot Jerry

[David L.]

Re: Alternator Fan

Jerry,

I believe the "5" on your 3909815 fan-pulley represents May, the month it was made. I have a 3909815 fan-pulley with the number "11" which I believe represents November because I took it off a 1100693 alternator dated "6 M 13" (Dec. 13, 1966).

What is the date code on your 67 Corvette alternator? maybe May or June 1967?

Dave

[Gerard F.]

Re: Alternator Fan

Dave,

Here's the alternator reassembled after my refurb:



7F16, or June 16, 1967, fits my June 29,1967 Assembly Date, as well as the May pulley.

The case was refurbed with Eagle Mag cleaner with lots of elbow grease with brushes. It says 37 Amp, but has a rotor and stator from a replacement 60 Amp.

One mistake though. The original stator insulation and metal plates between the halves was black, not the red or caramel. I should have painted it while I had it apart.

Oh well, maybe next time.

[David L.]

Re: Alternator Fan

Jerry,

Back in the 1980's when I collected many alternators dated in the mid to late 1960's at junk yards and swap meets I suspected that the number on the fan-pulley might represent the month it was made (for quality control, I assume). I'm sure I will get resistance with this theory from some Corvette owners as this may affect the score they get at car shows. I could care less about the car shows and the scoring system. I just find it more interesting studying vintage parts, part numbers, and date codes.

Dave

[Wayne M.]

Re: Alternator Fan

Dave, others --- here's the backside of my '3909815 AJ' showing a stamping "1" on one of the blades. You can see the backside mirror image emboss of the part # stamp; pic of front posted elsewhere recently.

Can't remember what alternator I pulled this off, but could be a 7B13 "693" that I have.

[Joe L.]

Re: Alternator Fan

Tim,

I know that I have 2 or 3 these fans in my collection. The "8161" stamping is not a GM part number or even a partial GM part number, maybe a vendor part number. My educated guess is that that your fan may be GM part # 1966990 (11 blades, 5 3/8" O.D.) but I would not bet the farm on it. I'm sure someone in the NCRS must have a NOS 1966990 fan for comparison. I might even have one. When I get a chance I will check my collection.
The 800594 fan is similar but I believe it has only 10 blades. GM # 1966990 was replaced with GM # 800594 in Jan. 1971 as per Chevrolet Parts History.

Dave

Dave------



Here are photos of an NOS GM #1966990. There are also photos of a used fan which was the original fan supplied with my original 1969 GM #1100859 alternator. I believe this to be an 1966990, too. Note the difference between the two is the C-shaped "cut-out" seen in the wide blade of the NOS piece. I believe that the 1966990 was made both ways.

[Joe L.]

Re: Alternator Fan

Here are photos of an NOS GM #800594: