65 SB 7 blade fan

[Ralph A.]

I have a 65 327 ac car with a 7 blade fan with center hole in the fan of 2 1/4" in diameter is this wrong for my car because all the original fan clutches I see have a 3" in diameter flange that will not fit through the center hole of my fan. thanks

[Joe L.]

Re: 65 SB 7 blade fan

I have a 65 327 ac car with a 7 blade fan with center hole in the fan of 2 1/4" in diameter is this wrong for my car because all the original fan clutches I see have a 3" in diameter flange that will not fit through the center hole of my fan. thanks

Ralph------

Your application originally used a 7 blade fan. However, I'm not sure if the one you have pictured is that fan, or not.

Fans used with thermostatically controlled drives from 1960-1970 had a center hole that was right at 2-3/8" although there might have been some slight variation, so you might want to check your measurement.

As far as original fan clutches with a 3" diameter hub, they might be original but they are not original to any Corvette I know of. A 3" diameter fan clutch hub would not fit through a 1960-70 fan (2-3/8" hole) or a 1971-82 fan (2-5/8" hole).

[Wayne M.]

Re: 65 SB 7 blade fan

....Fans used with thermostatically controlled drives from 1960-1970 had a center hole that was right at 2-3/8" although there might have been some slight variation, so you might want to check your measurement....

Ralph -- I agree with Joe L. GM engineering drawings show center hole at 2.375 to 2.377" diameter. Did a rough caliper check on a fan clutch hub I have and I get 2.315", so it's a snug fit.

BTW --- flat head rivets or mushroom head ?

[Peter L.]

Re: 65 SB 7 blade fan

Ralph - The fan looks like what I would expect for a 7 blade fan assembly for a 64-65 Corvette w/ C60. Please send Wayne the info on the configuration of the rivets as I know he's researching that. We need that info but once the Spring/Summer thaw hits up there I hope he will get out and get the old rubber off this tires. After all, he only has a few days to do it and it will be Fall again. Wayne is that why you never complain about your cars overheating..

Anyway, Ralph please post a picture of your fan clutch (because curious minds want to know), but as you might guess if the fan is "correct" than it's unlikely that the clutch is and visa-versa; so hopefully we can get you some sage advice.

Pete

[Tony S.]

Re: 65 SB 7 blade fan

Wayne. It was 96 in K.C. today. Do you mind sending some of your cooler air down this way?
Tony

[David L.]

Re: 65 SB 7 blade fan

Ralph,
It looks like a 64-65 Corvette w/AC fan (made by Hayes-Albion) to me, GM # 3853943. The hub hole should measure 2 3/8" in dia. and the bolt circle of the 4 clutch mounting holes should measure 3". The measurement from the center of the hub hole to the tip of any blade should be 9", making it an 18" fan. The pitch should measure about 2 1/4". I currently have about 40 to 50 fans for "muscle car era" Chevrolets, Corvettes, etc. and have sold quite a few fans over the last 20 years. The 3853943 fan is rather unique. The 7-blade 18" dia. 64-67 Pontiac GTO fan (GM # 9777014) is very similar except the GTO fan has aluminum blades.
Dave

[Peter L.]

Re: 65 SB 7 blade fan

Tony - That's why Wayne has that 65HP, C60 car up there and as you can see it's working for him. . He's and the rest of us think we're riding in a BIG BLOCK car; if only we we were not stuck in traffic. Pete

[Ralph A.]

Re: 65 SB 7 blade fan

You talk about A tight fit, I measured the fan again it looks to me that it is a 32 smaller then 2 3/8 that they said it was, but all i had was a tape measure, but i do know that the hub on aftermarket one is 2 1/4 thanks all

[Joe L.]

Re: 65 SB 7 blade fan

You talk about A tight fit, I measured the fan again it looks to me that it is a 32 smaller then 2 3/8 that they said it was, but all i had was a tape measure, but i do know that the hub on aftermarket one is 2 1/4 thanks all

Ralph-----


I can tell you that the hub on the GM #3916141, which is the closest thing available today to the configuration of the original clutches, will fit through the hole on 60-70 Corvette fans. If you find a fan clutch for which the hub will not fit through the hole, then you've found an incorrect and non-original fan clutch for the application.

[Ralph A.]

Re: 65 SB 7 blade fan

Well I just bought an original fan clutch off a fellow member and I'll have it next week if it fits grate if it doesn't I'll be back, thanks Ralph

[Joe L.]

Re: 65 SB 7 blade fan

Well I just bought an original fan clutch off a fellow member and I'll have it next week if it fits grate if it doesn't I'll be back, thanks Ralph

Ralph-----

I can tell you this: if it doesn't fit then it's NOT an original fan clutch for your application. Period.