428 Cobra Jet Radiator Cooling Fan Identification

Ford radiator cooling fans are identified by basic part number 8600. During the course of 1968 - 1970 Mustang production there were several different fans used to keep our Cobra Jets cool. All were driven directly by a pulley attached to the front of the cast-iron water pump; electric fans were not used. Both fixed-pitch and flex fans were used depending on cooling needs, often dictated by the presense of air conditioning.

All of the fans were built using a stamped steel center section and aluminum blades that were attached to the center section with rivets. Small washers under the rivet heads were often used to balance the assembly. Fixed-pitch fans typically came equipped with a fan clutch that allows the fan to free-wheel a bit when not explicitly needed. The original black paint was applied by dipping, so runs and other imperfections should be quite common.

Here's a table of confirmed applications by year according to examination of original build sheets and member input. Examples of both types of fan are included below.

Fan	Number of Blades	Diameter	Type	Year and Comments
C8OE-B	7	18.25"	Fixed-Pitch	1968
C9ZE-E	7	18.25"	Fixed-Pitch	1969 CJ and V-code SCJ, 1970 CJ with a/c
C9OE-H	6	18.00"	Fixed-Pitch (no clutch)	W-code 1969 SCJ, some 1970 SCJ
D0TA-C	7	18.00"	Flex	1970 CJ and SCJ without a/c

I've also seen a Mercury Master Parts Catalog reference to a six-blade, 18.00" flex fan used on 1969 SCJ Cougars with casting number C9OE-G (which was itself replaced by a C9OZ-D fan in November 1968). I've seen one build sheet that documents this fan being installed on an SCJ Mustang with a scheduled build date of September 13, 1968. The C9OE-H build sheets that I've seen have December 1968, January 1969, and September 1969 (that's in the 1970 model year), build dates, though I've also seen build sheets with C9ZE-E fans used later in the 1969 model year.

Looking at the 1975 Master Parts Catalog listings for these fans, I have to believe that some of the entries are mistakes. For example, it lists the C9ZE-E fan for use on a 1970 SCJ with air conditioning. The problem is that air conditioning wasn't available on the 1970 SCJ!

Here are some pictures of the C9OE-H fan, including the casting numbers and date code stamping and another date code, courtesy of Mike Bellaire. Notes from Mike: "The pics show this fan is dated August 1968 (H68) and October 1968 (K68); note the weird upside down R with the bottom cut off that they used for the "H" in the casting number. The October 1968 date is only on one blade on the front side".

I've also seen reference to a 1970 change-over date of 1 September 1969 for moving from the C9ZE-E fan to the D0TA-C fan. However, I've seen several build sheets for 1970 Mustangs built after September 1st with 428 CJ and air conditioning that used a C9ZE-E fan! I believe that 1970 Mustangs with 428 CJ and air conditioning continued to use the C9ZE-E fan throughout the model year. I'm very interested in seeing any build sheets that might prove otherwise.

Needless to say, this is one of the research areas where build sheets are very helpful because the build sheet clearly identifies the fan originally installed on your Mustang. If you have a copy of the build sheet for your car, please consider sharing a copy to assist with our research efforts.


C8OE-B Fan (with clutch)	C8OE-B Casting Number Detail

The C8OE-B fan (shown above) was used on 1968 Mustangs and Shelbys, and some early 1969 Mustangs. It actually looks a lot like the C9ZE-E fan.


C9ZE-E Fan	C9ZE-E Casting Number Detail

The C9ZE-E fan (shown above) appears to have been used on most 1969 CJs and SCJs, though some early units have been documented with the earlier C8OE-B fan. This fan requires a fan clutch.

The D0TA-C fan is a variable-pitch "flex" fan that adjusts air flow automatically by flexing the fan blades as engine RPM increases. According to the 1970 Ford service manual, "this fan adjusts itself to the engine cooling requirements without the use of complicated variable speed drive mechanisms". In other words, no fan clutch required. However, an aluminum spacer is required to mount this fan and maintain proper radiator clearance.


D0TA-C Fan	D0TA-C Casting Number Detail

Year	Service Part Number	Motorcraft Part Number	Engineering Number	Thickness (Inches)
1969	C8YZ-8546-A	YA-20	C8YE-8546-A	1.25
1970	C8YZ-8546-A	YA-20	C8YE-8546-A	1.25
1970	C6OZ-8546-D	YA-81	C8AE-8546-C	1.88

I've received a report that suggests that the 1.88" spacer is needed to allow the fan to clear the crankshaft pulley on a 1970 SCJ with power steering. I'm not sure why the MPC lists the shorter spacer for both '69 and '70 SCJs, but it does. The 1969 Osborn Engine Assembly Manual lists a spacer with an engineering number of ECZ-8546-E for use with the C9OE-H fan.