Snow Hogg uses a 13 hp Honda GX 390. Not sure, but I think Agri Fab uses a 11 hp Tecumseh.
On the tractor setup for my blower. It was on a 25 hp Briggs. I think probably 3600 rpm. The power came out on an electric clutch with a 6 inch pulley. From there it went by belt to a 10 pulley, belt to another 6 inch pulley by belt to a 9 inch pulley on the 15.5 inch impeller. I get 5400 rpm with a fan tip velocity of 21870 ft.min. When I do the math on this, it tells me that I am way over on the ft/min on the discharge velocity. That is if the ft/min velocity is the same on this type of blower versus a pto driven blower. I find you want a discharge velocity of 4000-5000 ft/min. On the new sears blowers on their 26 hp lawn tractors, they went to a 42 inch blower and a 12 inch impeller. They have a 6 inch electric pulley, belt to a 9 inch,belt to a 5.5 inch,belt to a 7 inch that is on a 12 inch impeller. When I do the math on that it still tells me that velocity ft/min is high. I have read something about high output impellers.
I'm wondering if I am doing the math correct.
RPM is 3900 coming out of motor and impeller diameter is 15.5. I get 2600 rpm with a 6 inch electric clutch/break on the 9 inch impeller pulley.
Rpm= Engine rpm x pulley size on motor devided last pulley size.
Fan tip velocity= in my case (15.5/12) x 3.14 x 2600=9490 ft/min.