I am a member of a club in Arvada. Elevation at the field is 5973' above sea level.

Here's what I know from personal experience:

It takes a .60 minumum to hover a 5 pound airplane--and thats gonna be full throttle hovering--not 1/2 throttle

It takes a 1.80 to hover 12 pounds at darn near full throttle. That was a ST3000 on a Hanger 9 25% Cap 232 that weighed 11.75 pounds. Hovering was 3/4 throttle--with not much left for emergency situations.

An OS 1.20 Surpass (non-pumped) will ALMOST hover 10 pounds at full throttle with a 15-6 prop.

A Thunder Tiger .91 will pull a Kadet Senior around plenty good with a 14-6 prop--provided it doesn't weigh much over 8 pounds. I had mine rigged for long distance flight. 3000mah battery and 54oz of fuel. Plane weighed 15-16 pounds loaded for a long distance flight. It took every last bit of a 450' runway to get it airborne with flaperons down at 25 degrees. Not much you can do with a Kadet Senior that weighs 15 pounds--and has a .91 4-stroke--but fly it straight and level for about 2.5 hours. I never tried to land it fully loaded. Always flew it out of fuel and tried to land with only 4--8oz left in the tanks.

My World Models 80" 300S Patty weighs 15.5 pounds with a G-62 on C&H ignition. I can hover at 3/4 throttle with a Menz Ultra 22-10 at about 7200RPM. But, I'm too chicken to do it very close to the ground.[:-]

I put a TH .75 on a 5 pound airplane--Chief 40 size 3D Giles 202. It hovered at 1/2 throttle easily. Propeller was a Pro Zinger 13-5. Full throttle from a hover was like shooting the plane from a cannon. Straight up--in a hurry--for as far as you could see it. Quite a lot of right rudder applied to actually achieve a straight up climb at full throttle--lots of torque on that little airframe. I should have pinned and glassed the firewall--because I rippped it out after about 100 flights.

A Moki 2.10 will yank 13 pounds around--no problem. It will hover about 14.5 pounds--at full throttle--if you prop it right. 20-6 or a 20-8 prop

A Moki 1.80 will hover about 12.5 pounds at full throttle--but, thats with a cline and the tank on the CG

A BME 50cc engine turns a 20-10 pretty good--slap a 22-10 on it--and it's a turd.

A DA 50 will turn a 22-10 around 6500--6800 depending on the day. And the prop. Nobody running a 24-8 on a DA 50 at 6000' elevation. They just won't turn it.

Hope this helps.