Howdy! ...and a Fan blade question

[MMMM_ERT]

Hi folks,

I'm new to this board.  Some of you may remember me, I used to be on the old f-body-classic email list.  Pete Serino is the name and I still have my gorgeous 68 Camaro.   

Got a few questions and I searched the board for an answer but nothing came up.  This relates to an original fan-blade for my car.  I have long since replaced the original fan blade with an aftermarket fan (original got bent to heck when the water pump froze up and went through my radiator. ARgggh!)  Anyway, I am wanting to go back to an original 5-blade fan and fan-clutch (my car has original A/C)  I've been looking for  a fan for a while...a few 5-bladers show up on eBay, but no part numbers or just an "H" on them. 

Any input on where to find a good original fan?   What is the bolt hole spacing of said fan?  I read on CRG site something about 3" diameter for my application and 3.25 for big block or Z28.  What is the dimention between holes center to center?


Anyway, heres a pic of my car.   She made the Dan Lyons 2004 Camaro Calendar!

  

Thanks for your help!

-Pete

[lakeholme]

I do not keep my 68 (with AC) at my home, but I will measure the fan holes center to center over the weedend.  I see from the picture (by the way, great car!) that you have a 350.  Mine is a 327, but after looking at the service and assembly manuals, I THINK they are the same.  (To be honest, I've got a great freind who is a specialty mechanic and he does all my AC and electrical work.  AC is a mystery to me... but much loved in July in NC!)

If this will help in your search, the 68 assembly manual refers from the V-8 page to the RPO K02 page about the fan.  There, it refers to the fan (and it does show a five-blade in the drawing) as "3789562 Blade Asm - Fan" and the clutch as "3916139 Clutch Asm".  Not having my car here, I will have to check if my fan has the same or similar numbers this weekend.  I do not know.

Of course, someone (hint, hint) may see this and go ahead and give you an answer....

[MMMM_ERT]

Thanks!   

I do have the factory assembly manual and checked the "K02" option, it does show part numbers but not "dimensions".  Most of the 5-blade fans on eBay seem to not have an original part number...just and "H" or "W" on them and marked "front".   I am trying to figure out the difference that CRG calls out with the 3" or 3.25" on the fans.

I also see fan clutches on eBay with the part number 3916141 and they claim they are for 68 small block 327 or 350.   Wondering if these will work?  I don't care if the part number is correct so much.  My car is not totally original anyway. 

[KurtS]

The center lines of the four bolt holes are in a 3" or a 3.25" diameter circle.

[MMMM_ERT]

The center lines of the four bolt holes are in a 3" or a 3.25" diameter circle.

Thanks for the response Kurt.

I guess I'm still a bit confused, I have a small block so it should be the 3" diameter, correct?

The CRG page shows this:

Clutch Fans
In 1967 and 1968, the clutch fan was 18 inches in diameter, had five blades, and came in two types:

1967-68 fan for AC or K02 cars
For cars with hydraulic lifter engines with AC or K02 (except 1968 L34/L35 with K02), the 3789562 fan with a 3-inch diameter clutch-to-fan attachment bolt circle was installed. Three different fan clutch part numbers are listed as having been used with this fan, all having the matching 3-inch diameter bolt circle.

1967-68 fan for L78 and Z28 and 1968 L34/L35 with K02
The 3871276 fan was used on the 1967 and 1968 Z28 and L78, as well as 1968 L34/L35 with K02. The bolt circle diameter for the clutch-to-fan attachment was 3.25-inch.

[lakeholme]

I looked my five blade fan over, and you are right, I found no numbers.
I thought sure it would be 3-inch, but it looks like it is 3.25. (center to center)
I do know my motor is not orginal, but it is a 327 and the fan fits fine... and the air works great.
Not sure I really helped you, but good luck

[MMMM_ERT]

Thanks Lake! 

[KurtS]

I guess I'm still a bit confused, I have a small block so it should be the 3" diameter, correct?

The CRG page shows this:  ........

You wrote:
> I am trying to figure out the difference that CRG calls out with the 3" or 3.25" on the fans.

That's the difference, hence my response above.

Yes, you should have the 3" version.

Lake,
Make sure you measure to the centerline of the holes, not to the edges.

[lakeholme]

I really did measure it center to center.  But I'll go back and do it, again!  .25" isn't that big a difference, so I'll make doubly sure and let you know.
So, are 3" for small block and 3.25" for big block?

[MMMM_ERT]

I guess I wasn't descriptive enough....

So...given the difference from SB to BB...the clutch itself must have a matching bolt pattern. 

[KurtS]

Yes, the two fans require different clutches. I'll reword that part of the article.

[MMMM_ERT]

Thanks Kurt.

18" 5-blade fans are hard to find (in decent condition)  GM still carries a 17" 5-blade fan which is technically for a 60-67 Vette but has the correct 3" center to center holes for the fan clutch. 

Any reason going to a smaller 17" 5-blade fan would be a bad idea?

[KurtS]

Yes. It won't fit correctly/completely in the fan shroud and you won't get the cooling you want.