I recently got a P40 with a 73" wing span. It is suposed to have a 1.40 4c glow engine. I want to go petro to reduce fuel cost. What size 2cycle petro engine do I need for good power and flight without cutting away the cal. I have also considered a y engine like a SATO 200Ti 4c glow, or a single cylender ZDZ super 80petro. Is this the correct idea. It also has the engine mounted to a deck instead of the fire wall. Is this a show stopper for the firewall mount engines? should I go glow or petro? Any ideas on this would be appreciated greatly. oh ya, the plain kit says its waight is 10.5 lbs.

Well, going to gas in a smaller model will likely cost you a weight penalty. But, many newer gas engines are lighter than ever and provide as much power or more than a glow engine of similar weight.

In general, the weight penalty disappears at 50cc. In a smaller model like yours, consider the weight of the engine verses power in pounds of thrust for comparison.

You will probably want a 30cc gas engine or bigger, depending on weight. Remember, you want the plane to balance properly without adding weight to the tail or the nose. Look at the largest recommended engine and use that as a weight limit. When you make comparisons, remember to add the weight of mufflers, ignition battery, ignition and anything else that may be needed.

Gas is by far cheaper and easier than glow, but in your model's size range you may have to settle on a slightly heavier engine.

Good Luck!!

I'm thinking of the new ZDZ super 80 is this to much engine?

It would be 4.6lbs vs 2.0 lbs. 9.1hp vs 3hp. What would you do?

WAAAY too big. You need a 2-2 1/2 lb engine. Even a DA 50 at 3 lbs is too much. Do some research and see what's available.

Good Luck!!

6 have a 1.2 sized Chipmunk I am building, it will fly at about 16 lbs, and I am going to power it with a Zenoah G26, that will be lots of power, you may want to consider a a G33.

you should look into the evolution gassers, i know a lot of people are using them with great success. and im pretty sure they range from 20cc up depending on what your looking for,.

tHANKS EVERY ONE FOR YOUR ADVICE. I WILL BE LOOKING FOR SOMETHING SMALLER THEN.