[grivera]

Cross posted in 67-69 Bird section but no responses:

I am buying a RARE billet pulley set and in my conversation with rep, he said the 4.5" Flow Cooler water pump will work with the Firebird using the later style water pump pulley. They only have the pulley for the 4" pump in 7' diameter vs the conversion pulley which is 6.5" . To me it seems I have ample room in front of fan clutch for this conversion. Is there anything I'm overlooking or reason I shouldn't do this? I ask cause if the long snout could be used in early birds why didn't factory do it?

[Formulas]

One thing I encountered with mixing pulleys was belt spacing differences on double belt water pump and crankshaft pulleys
Not where any give belt in space is but how much space between each belt

[grivera]

I should explain it better. RARE sells this pulley specifically to run the longer snout pump on the 69 Firebird which comes with the short 4" pump. JBP manufactures a pulley for the same purpose. https://butlerperformance.com/i-2472...l%3Fq%3Dpulley

JBP: "Because the early 4" water pumps are no longer readily available, we have created a kit to switch over from the 1969 4" pump to the 1969 1/2 and later 4 1/2" pump. The included water pump pulley allows you to use all of your other stock pulley's and brackets with proper alignment."

Curious if aside from the extra 1/2' closer to radiator is there an issue I'm overlooking.

[Hikin Mike]

I switched over to the stock 4.5" wp, stock 9799128 pulley and Cold Case radiator last year with no issues in my 69 Firebird.

[Schurkey]

How far in the shroud does this place the fan?

[Hikin Mike]

Originally Posted by Schurkey

How far in the shroud does this place the fan?

Fan is about 3/4 in the shroud and I'm 2-1/2" from the radiator to the fan clutch.

[Schurkey]

Originally Posted by Hikin Mike

Fan is about 3/4 in the shroud and I'm 2-1/2" from the radiator to the fan clutch.

You need a shorter fan clutch, or a shorter shroud. That fan is too deep.

[grivera]

Originally Posted by Hikin Mike

Fan is about 3/4 in the shroud and I'm 2-1/2" from the radiator to the fan clutch.

Do you mind posting a picture of your fan in shroud? Also, what size and how many blades? Does is sit the same distance from shroud all the way around?

[Hikin Mike]

Originally Posted by Schurkey

You need a shorter fan clutch, or a shorter shroud. That fan is too deep.

Maybe, but I'm not changing it.


I should add, that there was no difference in cooling between the 4" and the 4.5 pump. I was hoping to get the car to run cooler in traffic, but that didn't seem to matter.

[Hikin Mike]

Originally Posted by grivera

Do you mind posting a picture of your fan in shroud? Also, what size and how many blades? Does is sit the same distance from shroud all the way around?

I can take a picture later today. It's a 7-blade fan that I bought from Ames. I think it's about 18-1/2" diameter. The shroud isn't even around the fan.

[Hikin Mike]

Originally Posted by grivera

Do you mind posting a picture of your fan in shroud? Also, what size and how many blades? Does is sit the same distance from shroud all the way around?

There is about 3" gap from fan to top of the shroud; 1" between fan and drive-side door shroud and 1.5 on the other side.

[grivera]

Thanks for the pics. Do you have AC? I also have Cold Case but with 19.5” fan. At top of fan edge about 2.5” clearance and the sides and bottom are 5/8”.

[Hikin Mike]

Originally Posted by grivera

Thanks for the pics. Do you have AC? I also have Cold Case but with 19.5” fan. At top of fan edge about 2.5” clearance and the sides and bottom are 5/8”.

Not anymore. It was a factory AC but when I got it, the A/C (and original motor/trans) where long gone.