1967 small block a/c fan blade ??

[David S.]

By reading the JG book says all small blocks are 17 1/8 dia ,5 blade.
no mention of a/c cars ?
Why is there a 18" blade listed in the 1967 parts book and the 1972 parts book. 5 blade ,#3789562 reads 66-67 corvette w/c.a.c.(which means car air conditioning)(327)2nd design.
has anyone every looked this up and came to a conclsion???
Thank you David

[Bill C.]

Re: 1967 small block a/c fan blade ??

By reading the JG book says all small blocks are 17 1/8 dia ,5 blade.
no mention of a/c cars ?
Why is there a 18" blade listed in the 1967 parts book and the 1972 parts book. 5 blade ,#3789562 reads 66-67 corvette w/c.a.c.(which means car air conditioning)(327)2nd design.
has anyone every looked this up and came to a conclsion???
Thank you David

David,
the 66-67 a/c sb fan is different than the std fan, the same fan was used in late 63 a/c cars. This has been well documented. Nolands book has a good description and drawing w/ part # if memory serves me correctly. If you need one send me an email and I can help
Bill Caldwell

[Peter L.]

Re: 1967 small block a/c fan blade ??

David - We have and it should be the same as for the 1966 sb, but I'm not clear why it's not in a 1967 TIM&JG. Anyway, here's what's in the 1966 TIM&JG:

"Air-conditioned small block cars used one of two fan assemblies, either 3789562 or 3863137. Both fans are 5 blade assemblies with an overall diameter of 18 inches and use 5 mushroom head rivets to attach each blade to the reinforcement. The reinforcement arms of fan blade assembly 3789562 have an elongated triangular shape, The center of the reinforcement is stamped with an "H" on the front. The blade reinforcement arms of fan assembly 3863137 have a rectangular shape. The front of each blade has a manufacture date, a blade part number, and a manufacturer's code stamped on three line near one of the corners. The date formate is M-Y where M is he month (A-L_ and Y is the last digit of the year. An example is:

C6
912239
SC

Hope this helps.

Pete

[David S.]

Re: 1967 small block a/c fan blade ??

Thank you ,Pete and David .That help out alot.

[Neal K.]

Re: 1967 small block a/c fan blade ??

I was looking for info on correct fan blade for 1967 sb with ac and read your thread. If I am correct in my reading of Nolan's drawing and discussion of the 3789562 fan blade on page118 of his book, it has an 18" diameter and 4 flat head rivets(see page 128 of the 1967 Judging Manual. The rivet pattern is in a pyramid shape. Am I correct on this or are the rivets mushroom heads.
Thanks
Neal

[Bill C.]

Re: 1967 small block a/c fan blade ??

Neal,
Mushroom head
Bill

[Wayne M.]

Re: 1967 small block a/c fan blade ??

David - We have and it should be the same as for the 1966 sb, but I'm not clear why it's not in a 1967 TIM&JG. Anyway, here's what's in the 1966 TIM&JG:

"Air-conditioned small block cars used one of two fan assemblies, either 3789562 or 3863137. ....

Pete -- interesting tidbit; the 3863137 appears nowhere in any of the (service) P&A30 catalogs of the '65-70 era (nor the parts history appendices), [production-installed only ?], whereas the 3789562, the 3770529 (base fan, no air or BB), the 3872792 (396), the 3888366 ('66-69 BB w/o C60), and the 3853943 ('64-65 seven blade with air) appear in the catalogs for at least 4 to 7 years (and maybe even longer if my catalog collection extended past January 1970).

[David L.]

Re: 1967 small block a/c fan blade ??

Wayne,

As far as I know the GM # 3863137 fan made by the Schwitzer was never sold "over the counter". The number only appears in the assembly manuals and not in the Chevrolet parts catalogs. I have studied fans for at least 25 years and have about 55 or 56 Chevrolet parts catalogs (1963 to 1981) as well as Chevrolet & GM Parts History manuals from 1963 to 1990.

It is also interesting to note that "early" 1969 Z28's used a Schwitzer fan (GM # 3937779) which was also sold over the counter. The optional Hayes-Albion "early" fan (GM # 3947838, sometimes stamped "84") was NOT sold over the counter. Likewise, the "late" 1969 Z28 fan (GM # 3947772 made by Schwitzer) was also sold over the counter but the optional "late" 1969 fan (GM # 3956684, stamped "94", made by Hayes-Albion) was NOT sold over the counter.

Dave

[Joe R.]

Re: 1967 small block a/c fan blade ??

I was looking for info on correct fan blade for 1967 sb with ac and read your thread. If I am correct in my reading of Nolan's drawing and discussion of the 3789562 fan blade on page118 of his book, it has an 18" diameter and 4 flat head rivets(see page 128 of the 1967 Judging Manual. The rivet pattern is in a pyramid shape. Am I correct on this or are the rivets mushroom heads.
Thanks
Neal

Hi Neal:

The drawing in Noland's book shows four rivets, and the discussion does not mention whether they were flat head or mushroom head. I have a NOS 3789562 fan that has four rivets as shown in the drawing. The rivets on my NOS fan are flat, but that doesn't really tell us what they looked like on the 3789562 fans used in production in 1967.

[Scott S.]

Re: 1967 small block a/c fan blade ??

This fan is from a '67 L79 with A/C, and I think

[Scott S.]

Re: 1967 small block a/c fan blade ??

A few close-ups of the rivets, front and back side:

.

[Scott S.]

Re: 1967 small block a/c fan blade ??

Two more pictures of the rivets from a side view, and two pictures of the "W" stamped on the back side of one blade-arm:

.

[Neal K.]

Re: 1967 small block a/c fan blade ??

I gather that there is a difference of opinion as to whether the rivets were mushroom, as Bill states, or the flat head ones mentioned in the 67 judging manual and shown in the pictures of Scott's L-79 a/c fan.
Even though I have owned this car for in excess of 40 years I didn't pay much attention to what was happening to original parts when the car went in for repairs. Now that I am restoring it I am finding out how little I really know about my own car.
As a new user of the Discussion Board I really appreciate the help.
Thanks
Neal

[Scott S.]

Re: 1967 small block a/c fan blade ??

I gather that there is a difference of opinion as to whether the rivets were mushroom, as Bill states, or the flat head ones mentioned in the 67 judging manual and shown in the pictures of Scott's L-79 a/c fan.

Hi Neal,

Bill's experience is undoubtedly much greater than mine. I'm new to this, just going by what the books say and the parts that came off my car. I have learned on this forum that the books are not always correct (neither are all the parts that come off the car...) and that's one reason I post pictures of the parts I have. If somebody sees something that's not right, I'm hoping they will point it out, and bring it to my attention.

[David L.]

Re: 1967 small block a/c fan blade ??

This fan is from a '67 L79 with A/C, and I think it is correct. It has ‘W’ stamped on one fan blade stem (back side), 'H' and 'FRONT' stamped on the front side hub, 4 rivets/blade, flat rivets, 18" diameter. Should be GM part # 3789562, see Adams p. 118 and p. 405

Scott,
Your fan is GM # 3789562 as it appears that the clutch mounting bolt circle is 3.00" with a 2 3/8" hub hole. The fan is made by Hayes-Albion ("H" stamping). As shown in Pete's post the other fan used was fan # 3863137 made by the Schwitzer company ("SC" stamping along with the Schwitzer part number 912239 as well as a date code). I have had several of each of these fans over the past 30 years.
Dave