Fan Shroud Info

[ACK]

Please share what you know about fan shrouds. It's a fairly popular topic, but I find more info about them on the "For Sale" board than on the "Message Board." Things like:

1. How to identify different years (markings, # of ribs, material, etc)
2. How to identify L6 and V8 shrouds
3. Can you use a V8 shroud on an L6 if you have a V8 radiator
4. Availability and quality of aftermarket shrouds

Also, why does the 5 blade fan look like it was designed by a drunken engineer.

[DanJC]

I don't know this for sure but I think this what you generally shoot for-
-fan an inch or so from rear of radiator
-about a third of fan blade width hanging out the engine side of the shroud
That being said, whether the shroud came from a 6 or 8 makes no difference if it fulfills the above criteria...
I think I heard something about the funny blade spacing has something to do with airflow, not sure??

[azdeltawye]

Originally Posted by ACK

...
Also, why does the 5 blade fan look like it was designed by a drunken engineer.

I believe the reason for the unequal blade spacing on the 5 & 7-blade fans is to reduce noise.

[ACK]

I've read 55-59 metal shrouds have 2 ribs and 1960-62 metal shrouds have 3 ribs, not sure if this applies to L6 and/or V8s. What years were Bakelite and were they for V8s only?

[Captainfab]

Yes the '60-'62 fan shrouds were steel and the '63-'66 shrouds were a composite material. I do not know the composition, but they can be repaired with fiberglass. I have not seen a I6 fan shroud either steel or composite, but I understand they do exist.

[Shorty Cox]

i'LL ADD MY $.02 TO THIS REGARDING SHROUDS. I MY TRUCK HAS A 283 THAT WENT BADDDD. I HAD A '84 305, SO I INSTALLED IT. ORGINAL SHROUD WILL NOT FIT WITH THE 305.

[ACK]

Originally Posted by Captainfab

Yes the '60-'62 fan shrouds were steel and the '63-'66 shrouds were a composite material. I do not know the composition, but they can be repaired with fiberglass. I have not seen a I6 fan shroud either steel or composite, but I understand they do exist.

I read that possibly later models with the I6 and air conditioning had a composite shroud, but it wasn't the same shroud as the V8s. Need someone to confirm or deny this.

Originally Posted by Shorty Cox

i'LL ADD MY $.02 TO THIS REGARDING SHROUDS. I MY TRUCK HAS A 283 THAT WENT BADDDD. I HAD A '84 305, SO I INSTALLED IT. ORGINAL SHROUD WILL NOT FIT WITH THE 305.

That's good info to know. Would it not fit because the 305 fan sits too high or too low to go into the shroud?

[Shorty Cox]

I'm sorry, I can't remember if the fan was too high or low. The fan was not "centered" in the shroud hole. I even tried to put a fan extension on the nose of the water pump to move the fan closer to the rad, but that didn't help.

[Captainfab]

A 305 is a small block just as a 283 is. The issue was likely because you used the long water pump that came on the 305 instead of the short pump that was on the 283. The original fan shroud will work with any Gen I small block with the short water pump and with the engine installed in the original location.

Originally Posted by Shorty Cox

i'LL ADD MY $.02 TO THIS REGARDING SHROUDS. I MY TRUCK HAS A 283 THAT WENT BADDDD. I HAD A '84 305, SO I INSTALLED IT. ORGINAL SHROUD WILL NOT FIT WITH THE 305.

[Sodak]

Heres the fan shroud off my 61 apache.

[LostMy65]

Originally Posted by Sodak

Heres the fan shroud off my 61 apache.

That's the one I had on my 62 gmc donor.

[jtrichard]

Originally Posted by Captainfab

A 305 is a small block just as a 283 is. The issue was likely because you used the long water pump that came on the 305 instead of the short pump that was on the 283. The original fan shroud will work with any Gen I small block with the short water pump and with the engine installed in the original location.

I agree with you 100% i have a 305 in place of a 283 in a 63 c20 and it fits just as the OEM 283 did a GEN 1 small block is a small block is a small block