Measure 11 blade diameter

[relayswitcher]

Can you tell me where you measure the diameter on the fan. I know they vary form 3.75" to 3.25" and so on. But where exactly do you measure. Can someone photo shop a pic with lines showing where you get the exact measurement. Thanks, Relayswitcher.... full of questions today.

[304065]

They are in mm not inches

245 mm from blade tip to blade tip across the center of the hole in the middle.

[carrera turbo]

i think maybe he means the pully size?


ed

[Henry Schmidt]

There are only two pulley sizes made by the factory for eleven bladed fans.
Large (early) 8 hole pulley and small (later) 12 hole pulley.

[carrera turbo]

Originally Posted by Henry Schmidt

There are only two pulley sizes made by the factory for eleven bladed fans.
Large (early) 8 hole pulley and small (later) 12 hole pulley.

so is his question legit is there a 3.25 and a 3.75 pulley ?

i thought i have heard this as well.

thanks ed

[relayswitcher]

I know it's been since January, but the measurements go as follows. And I found this in a Pelican tech article regarding changing out your fan to 11 blade....etc.

This measurement is taken from the metal "bumped up area" diameter at the center out to where it starts to flatten out for the big rivets .

911 & Year Fan Pulley Diameter
911 1965-74 3.75"
911 1975-77 3.25"
911SC 1978-79 3.125" (I think this is a mistake and should read 3.25.....not sure though.
911SC & Carrera 1980-89 3.25"