if you have enough cooling air passing over the can of the motor - then no you dont need a fan at all.

Please heed the "IF" in Wynn's reply (and Dean's).

Kim did a lot of research to come up with the Plettenburg set up used by Paul. Kim highly recommends the fan. Paul and Kim use the fan on this motor. I use the fan on all the motors that offer them (my Plettenburg's and Hacker's).

Like Kim says: "...... they weigh almost nothing and they help a lot on hot days with no down side .... "

Our motors are better the colder they are (they really would like to be well below zero C). The fan is good, light, inexpensive, insurance.

But, like Wynn says, if the "IF" is taken care of you will be OK without a fan. We do have thousands of E flights without them.

But I like to copy the best pilots setups when I can, if Paul and Kim use them, I will try to also. ;-)

BTW: Kim says the fan works from the front or the back. So have them mount it to fit YOUR installation preference and you will be happy. :-)

Regards,