if not help me find help on the designing of the fan,thrust mesusrement eqipment,needed thrust isto weight ratio,MAINLY plz help me out on the meterial used as cloth/wing in modern microlights. l NEED PROFESSIONAL HELP FRIENDS PLZ HELP ME. sites address r also welcomed :D/

l used to take pilot training. And one of the things l learned was that the airplane engines were very LOW tech but very reliable.

Ex: airplane engines use Magnetos instead of alternators, because Magnetos r MORE reliable (but less efficient).

Modern engines (cars & motorcycles) r very high tech to draw lot of power, etc. On an small airplane what is #1 importance is reliability.

You do not want ur FIRST engine failure to be ur last failure. Do not think like a car driver. Think like a pilot (safety #1).
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So go with proven airplane engines (Rotax).

http://kodiakbs.com/


Good Luck.

My advice is start with a proven design. You could buy a complete aircraft, or at the very least start off with good plans. having a good, stable plane is MUCH more important than how it gets its power.

To answer your question, your engine should make enough power as long as you gear it down. Depending on the pitch of the prop, you do not want much more than 3000 rpm.

Do not reinvent the wheel until you understand how it works.

It will probably fly if designed properly BUT motorcycle engines run too fast to be practical in an aircraft. You will require an expensive and heavy custom made reduction system to bring the revs down to an effective prop speed.
You would be better served to look at an engine system designed for this application. It would be more practical and reliable.