Andrew, I think for an accurate comparison, you need to operate the IC motor as we do for stunt. My guess is that the horsepower number you have is the peak horsepower. We dont run it anywhere near peak horspower in a stunt run so that skews the numbers IMHO
Do you know if this was the number published by the manufacture for the engine or one that was generated by testing?

For quite a while, the standard was to figure 150 watts per pound. Of course, more is better excepting you have to carry the extra battery aloft.

Hi Larry and Andy,

I do not mean to sound like I am, in any way, giving advice to someone that has a PhD from MIT. (Ed. Note: Larry knows more in his little fingernail than I know in my whole brain, and Andy is a very smart computer engineer). Sooooo with this qualifier, here is my very humble input to this thread:

Mark and Jim are on the right track. If you are trying to get a power comparison you can use 150 watts per pound as the very minimum for CLPA and 250 as the top max needed. The 180 to 210 range is ideal. Yes, I know you can get by with less if you have a thin airfoil, and sleek low drag plane, but modern CLPA seems to be going in the other direction, thus the 200+ watt recommendation.

As was suggested, using the above info. and looking at the wet engines normally used in the planes on this sections "setups" post at the top of our page will give you a very good idea which motor/setup equals which wet engine/nitro. setup.

Another place to look would be the "Hobby Lobby" web site. They give wet engine equivalents on all their AXI motors, they have a chart for this too. ..... Also the Hanger 9 (E-Flite) site gives wet engine comparisons. Both also mention what wt. plane is covered by their motors. I find that getting a motor that is recommended for a 3D weight that has the weight of my CLPA plane at the lower part of their weight scale is what works best for our modern CLPA planes.

The above sites and info should go a long way in helping you evaluate the validity of your formulas.

I know you guys are trying to make it easier for a newcomer to select a setup, and that is a very good thing to have and will be a welcome tool. But the good news is that we have such a large data base of ECL systems out there now that it makes it very easy for a newcomer to fly ECL, even if they do not know which wet eng. would have worked in their plane in the 1st place. :-)

Regards,   

Rudy
I agree with Dr. Renger 200w/pound is a simple way to compute what we need.  Larry your modesty is overwelming, oh boy I am going to have fun with this.  Thank you so much Rudy.
Andy