fans

[Dale S.]

I have read and seen advertised 7 blade fans for C-2 cars with A/C. I have an original 67 C-2 with A/C. It has a original five blade fan and original fan clutch and no offset license plate mounting bracket. Did either of these items (7 bladed fan & offset license)ever appear on any C-2? I would like to hear from other owners of A/C equiped C-2's. For a while I tried to buy a 7 blade fan for mine,thinking maybe the factory had made a mistake. After buying and returning 3 fans(they could not measure the mounting hole's or would not) I gave up. Thanks in advance Dale

[Kent K.]

Re: fans

Dale,
My '67 327ci/300hp A/C Corvette came with a 5-blade fan from the general to the best of me knowledge and photos from the 2nd owner in the late 60's. 427ci engined '67s with A/C may have been assembled with 7-bladed fans but, someone more knowledgable than me will have to answer. The offset license plate was used on BB cars with A/C to permit more air passing through the radiator for additional cooling. Again, there are people out there who have more research knowledge than me.
Good Corvetting,
Kent #6201

[Jack H.]

Re: fans

The factory was known to substitute 7-blade for 5-blade fans and vice versa at times. Typically, info on this IS given in the descriptive text of the Judging Guide applicable to your particular car (year & engine configuration).

[Peter L.]

Re: fans

Dale - '64 and '65 Corvettes w/ C60 used a fan assembly w/ 7 blades. The information available indicates that '63 w/ and w/o C60 used a 5 blade fan assembly and '66 and '67 sbs w/ and w/o C60 as well as '66 and '67 BBs all used 5 blade fan assemblies. The sb fan blade assembles w/ and w/o C60 do differ in diameter. The '66 TIM&JG under the sb fan assembly does indicate "There are undocumented cases of 7 blade fans on air-conditioned cars." Pick you poison but for a '67 sb or BB w/ C60 make it 5 blades. Pete

[Dale S.]

Re: fans

well mine is 67 SB with A/C with 5 blade and all original. so I will leave it alone. thanks Dale

[David K.]

Re: fans

My April '67 427 (L36) with C60 has the 7 blade fan, which I believe to be original.

[Joe R.]

Re: fans

Hi Dale:

I researched this topic a few months ago, and it seemed that the consensus view was that most 67 AC cars were assembled with a 5-blade fan.

However, the 5-blade AC fan called out in the AIM (part number 3789562) is not the same as the 5-blade base fan (part number 3770529). The 3789562 blade has a steeper angle and the riveted flanges have a different shape. A photo of the 3789562 fan can be found at
If your car has the 3789562 fan, you should be all set. If it has the 3770529 base fan, the situation is less clear. I have heard that base fans showed up on some of the early AC cars that are believed to be original, and that some judges have concluded that the factory may have sometimes installed base fans on early AC cars. I do not know whether there is any evidence that this might have occurred in 1967.

[Peter L.]

Re: fans

Joe - Nice jpg picture. The reference to the 3770529 showing up on "early" Corvettes w/ C60 from what I have read is associated with the 1963 model year Corvettes w/ C60. Whether this is fact of fiction with reference to '63s, I don't know and I don't know that the '63 folks took the fan blade assmblies off and measured the diameter or had some scheme to make an accurate measurement in their sampling because these two fan blade assemblies do look similar at least at first glance. The 37770529 fan blade assmbly has a 17-1/*' dia. while the 3789562 fan blade assembly has an 18" dia. I am not aware of documented cases of this situation for '66 or '67 sb C60 Corvettes. I can at least confirm it was not typical on early '67s because my '67 (S/N 1476) has the 18" dia 3789562 fan blade assembly. Pete

[Dale S.]

Re: fans

My C-2 SB with a/c has a 18" fan, what is the location of the part number? thanks again Dale

[David K.]

Re: fans

I did not realize how controversial my statement was when I posted it.
It is certainly possible the fan was replaced before I got the car, and I was unaware. It is an L36/C60 car with the 3:36 rear end, of which I heard there are supposed to be few possible cases with 7 blade fans.
I was unable to locate a part number on the fan (I plan to remove it and look more closely soon).
The fan looks like the drawing in the Noland Adams book for part 3853943.
Each fan blade measures approx 6" on the long side, 3" on the short side, and 4" wide. Some, but maybe not all, blades are stamed with "H C60E-G" along the longer edge of the blade.
Can anyone provide me with an identification based on these few clues?

[Craig S.]

Re: fans

Dale - there are no part numbers stamped on the fans. On some fans, such as the "optional" AC 18" fan shown in Noland's book, carry a vendor number on the blades and date code, and this vendor used a "dice pattern" blade attachment. By optional this was not a customer option, rather, a vendor choice on the assembly line....Craig

[Joe R.]

Re: fans

Dale:

You asked where the part number is on the fan, and Craig has explained that some fans have no part number. Identifying the fan that you have requires a little detective work, but with the aid of the factory drawings in the Noland Adams book you may be able to identify your fan.

Key identifying characteristics include the diameter, the number of rivets on each blade, the spider shape, and the rivet pattern. Sometimes the shape of the blades and the angle of the blades can also help distinguish the fan.

Do you have the Noland Adams book available? The chapter for each year includes a discussion on the C60 air conditioning option and the fans that were used. Base fans are also described. I find it remarkable that GM used so many different fans in midyear Corvettes.

If you don't have the Noland Adams book, you can try sending me a photo of the spider side of your fan and I will see if it matches any of the drawings in the book. My email address is jpr3@aol.com.

[Joe R.]

Re: fans

Hi Dale:

Does your fan have four rivets per blade or five? The NOS service replacement 3789562 fan that I have has 4 rivets, while the 3770529 base fan has 5 rivets. It has been suggested that maybe later versions of the 3789562 had 5 rivets, but I can not confirm this.

[Joe R.]

Re: fans

Hi Kent:

Does your fan have 4 rivets per blade or 5?

[Kent K.]

Re: fans

Joe - My 1967 A/C Corvette (mid-production run) fan has 5 rivets per blade in a diamond pattern with one in the center and one at each end of the x.
Kent #6201