ORIGINAL: USSCAT
Charles,
I believe JMP (jet model Product
http://www.jetmodelproducts.com ) still sell the fan unit. You may even try RAMTEC fan (spelling??) which is suppose to be a better match for the OS 91. You can probably find a used combo on RCU, I have two or three fan units (my spares) if you are interested. They are used but in good shape.
Regards,
Mike
Gents,
On a previous thread, and in discussion with the vendor, I was warned not to use a Ramtec Fan. IT needs more air volume to operate than you can pass through the Hawk.
RCJI had a review of the Hawk, a couple years ago. The conclusion was that the best powerplant was the lightest. That being either a K&B 48 or OS 46 VR. The extra weight of the 90 size engine, and fuel, did not really pay-off against the lighter 40 size set-up. Weight is a killer in ducted fans......
Might want to look up the old review.
DW_Crash