Will the Derale Radiator Race Fan # D17420 Replace the Factory Fan in a 1988 Ford F-250  

Question:

Expert Reply:

The Derale 20 Inch Race Fan, # D17420, has a 19-7/8 inch diameter so it will fit within your 22 inch shroud. One thing to keep in mind with this fan is that it is a race fan which means it will require you to remove your fan clutch as well. It is designed to pull more air as your engines RPMs increase and not to be regulated by a clutch.

Removing the factory clutch will effect the length of the spacer that you need. Once you have the clutch removed, you will want to measure from the water pump flange to the edge of the mounted shroud and add 3/4 of an inch for your spacer length. I have attached a photo showing this measurement. I have also attached a link to all of the spacers that we carry so you can select the correct length spacer after you determine the proper length. Our fan spacers include the mounting hardware.

Fan rotation is also important, be sure you check if your factory fan has a standard rotation (clockwise) or a reverse rotation (counter-clockwise). The radiator fan # D17420 that you referenced has a reverse rotation. For standard rotation, you will want radiator fan # D17320. I have also attached an article on radiator fans for you to check out.

expert reply by: John H

0

click to enlarge