Iam Raj Kumar Narisetti studying aeronautical engineering.
We have a project to design and build a flying model or
you can say model aircraft.

WE ARE CONVERTING A POWER SPYAYER ENGINE TO

AN AIRCRAFT ENGINE. IT IS A 25 CC ENGINE WHICH

DELIVERS 3000 RPM AND WEIGHS 1-2 KG (Approx.)

INCLUDING FUEL TANK .

NOW, CAN THIS ENGINE PROPELL OUR 5 KG MODEL

INTO AIR.

{ we are'nt trying to use light weight glow engines or
cox engines due to procurement problems }

5kg is 11 lbs, which should be no problem for a 25cc gasser, as long as you design in enough wing area. Plan on no less than 1000 sq. in. and probably better at 1200 or so.

I am sure you can squeeze more than 3000rpm out of that engine.

I am really thankful for your advice ,surely we have

got loads of confidence now, if any hassles we'll surely

post a thread. or why dont you try to give me your

mail id so that in future (if you are free) can help us

in making our project successful !! Thank you !!

Please take pictures, and keep us updated. What brand of engine is it. Send airframe pictures also, we like airplanes too.

I am not free, but I can be extremely cheap sometimes.

Seriously, you are welcome to email me by clicking on the "e-mail" button below any one of my posts here. Or better yet, post your question here and get everyone's opinion instead of just mine.

You'll probably get a lot more help here if you can give more description of the particular engine (brand, model number, etc.) and plane. Pictures can help a lot also.

Good luck.

I know for a fact that you can get at least double the rpm out of that 25cc engine. It may only make 3000 on the sprayer due to a speed governer, as soon as that comes off you'll be laughing.

Can any one help me in finding the maximum amount of

thrust that I can generate using this 25 cc gasser , with a

look at every permutation possible, probably i may have a

15-18 inch prop (max. i feel) ,we need to design that ,and

peak rpm as you said would reach 5000 ???

During break-in, my 25cc WeedEater® conversion measured 8 Lbs static thrust with a 15 X 8 prop.

My next prop will be a 16 X 8, and should provide a bit more "umph".

What are the basic elements of converting a power sprayer

engine or go-cart or weed wacker engine into aircraft one.

I know the fact that it doesnt have flywheel generally,instead

its been balanced by prop. In similar ways, what are the other

basic elements that a general model aircraft engine should

possess ( if it were converted) bearing the fact of

weight reduction ?

Hi Radil,

If you go to the website www.rcfaq.com, and then click on "engine conversions" on the left side, you will find a lot of basic helpful information.

You will want to take off all unnecessary parts, and cut or grind off any unnecessary metal to make it as light as possible. A battery powered ignition system conversion will be lighter than the original magneto ignition, but you can run it either way.

If you can find out the manufacturer of your engine, there might be a kit available with all the parts necessary to convert it for airplane use, such as a propellor adapter, etc.

Hope this helps,
AV8TOR

Hello,

Last time I mentioned my engine as a 25 cc gasser and

weighing about 2kg , but recently we bought a new

one. This time these details are absolutely correct .

POWER SPRAYER ENGINE

34 CC ; 4.7 KG INCLUDING FUEL TANK, SILENCER,

1.5 HP (MAX) , MAX RPM 5500

DO YOU THINK THIS IS A NICE CONVERSION FOR

MY 9.5 KG OR 20.94 Lbs(Approx) MODEL.IAM USING

A 20x8 PROPELLOR (IT MAY PRODUCE STATIC THRUST

OF APPROXIMATELY 11 Lbs . with our calculations)

Next time I'll send pictures so that it may be really helpful to

you.

you would get more thrust with a 20x6 and let the rpm come up a little, we could better help you if you we knew exactly what engine you have.

Darin