Small blower/vac with fanblade?

[Number21]

Originally Posted by Treemonkey1000

You could just strap a shop vac onto your back. Drive it with a little 2 stroke motor...

Problem is I don't want a little 2 stroke motor. I want my 6.5hp monster.

[joes_427_vette]

The ford fan unit won't be very useful as it is intended to draw small volumes of air through the radiator cores an inch away. If you look at lawn vacuums they have a 8-10 inch diameter piece of steel with 3-4 inch blades. The flat blade area is what is going to move massive amounts of air ( and what ever is fed into the system > ). Two cycle engines benefit from the small blades and short fins with the thousands of rpm they produce blowing but little vacuum capabilities.

[RonMar]

Fans are HIGH volume LOW pressure... Actually those little high speed two stroke impellar/blowers generate quite a lot of vacume. My little 30CC monster lifts leaves and grass up a 4' diameter pipe at pretty high velocity. But you are correct, that it gets this by high RPM. The same thing can be achieved with a larger diameter impellar at lower RPM though.

As for a blower for a 6.5Hp 3600 RPM engine, I think I would trust steel and welds before I would trust something assembled out of plywood. You could fabricate something similar to a shopvac/turbocharger impellar,



which would need to be installed in a tight fitting caseing. This one shown would spin counterclockwise as seen with the air being slung outward from the center. It would of course need a center boss with keyway to match your engine shaft. You would need to plumb the center of the blower housing(low pressure point) to the side of a sealed box near the top. You could then feed the box from the other side just like a large shop vac.