Mechanical radiator fan question

[LukeZ]

Quick question. Does the radiator fan (mechanical, not electric) spin at an equal rpm to the crankshaft? So if I am at 3500 rpm, then that's how fast the blades are spinning?

 

[olds307 and 403]

Without a clutch fan, yes.

 

[LukeZ]

Without a clutch fan, yes.

So I have a stock LG4 305 Chevy. Do you (or anyone) know if these have clutch fans or not?

 

[olds307 and 403]

Most have the clutch, my 260 is running a solid fan off my non A/C 70S. If it has a silver finned ring, it is a clutch fan.

 

[LukeZ]

Most have the clutch, my 260 is running a solid fan off my non A/C 70S. If it has a silver finned ring, it is a clutch fan.

Thanks

 

[Rktpwrd]

Fan clutch:

 

[olds307 and 403]

Fan clutch:

View attachment 62781

We have a winner! If this is attached, clutch fan. It is supposed to adjust speed with temp.