Hi, I'm playing with some conversion motors and I'm wondering what weight to power ratio I need to use as a guideline.
I have a few that I want to try with the Glow/Gas and some with stock ignition and one new module I've bought to see how it's done. It's just new to me.

Here is a picture of an airframe I'm thinking on putting a gas motor into. But it must be an old trainer of some sort, as it has no ailerons on the wing. The wingspan is 82 inches and I’ll get a weight here in a little while.
Do any of you know what this plane is?
Here is the motor I'm thinking about trying, blower motor conversion. Anyone know if the no ailerons on the wing will be a problem with a conversion plane?
The motor is 25or 26 cc gas .
Is there a motor to gas motor reference out there someplace? Thanks for any help.

Motors weight is 3lbs 11oz as seen in picture.
Airframe weight is 8lbs 5 oz without servos or fuel.

Can't help you but the engine is too pretty to use.

Bill

I used a ryobi 31cc on a 14lb bandito grande. It was a 82"ws and I think the cord was about 15". Comes to about 1200+ sq". The engine flew with a 18x6 master airscrew at about 6700 rpm. At that weight with that engine, it had very lively performance. Not 3d but was a ton of fun for general aerobatics.
Edwin

chicks5, If you do work on airplanes much, you could cut out the size you want from wing and install hinges and have aileron's. It would respond a lot better. Capt,n

captinjohn , I had though of that, but I'm woundering if this would be a good match for the extra weight of the motor. It has plenty of room in the cabin. I was thinking I'd move the fuel tank back to under the wing and move the battery back as a tail weight.
What would be a good target wing square inch to weigh ratio?

As far as I've ever heard.....its never a good idea to move the tank back. Its always best to keep it as close to the engine as possible. Maybe others will chime in on this.

that motor sure looks like a mcculloah 25.4cc blower engine......should have no problem pulling around that airframe!

if he's just moving it to under the wing, that's fine, gas engines have pumper carbs that don't care about the tank position, they'll pull fuel about 4 feet vertically I believe, plus under the CG there's less change in balance when flying anyway.

on my ultrastik lite I moved the fuel tank to under the wing and moved the battery to under the back of the wing to get it balanced, haven't flown the dang thing yet though, finished it right as the weather turned crappy and the daylight went away quick...

That motor is a 25cc toro.I bought 8 of them off of ebay and sold them all already.You can run a 16x8 on it easily.It will fly the plane perfect.
I have a 96 inch ws Spook thats a 3 channel only.Flys like the old Buccanears,Miss Americas,ect...Yours should be fine.The only really interesting part is trying to land in a cross wind.Since you only have rudder,evry time you move the rudder to stay on centerline of runway you bank the plane.
Me and another guy{he was flying his Miss America],it was so windy after takeoff,he landed head on into the wind,acroos the runway.
As Captn said,adding ailerons is easy.That motor shouldnt weigh over 3lbs if i remember right.

Buck1856, Can you post a photo of one of your Toro engines. I got one also to convert! Capt,n

Chicks5, as long as you stay above 900 square inchs you should have good luck, of course the airframe weight comes into play, but I have put the toro 25 on a few planes in that size and larger and it seems to work well...

Heck I have a toro 25 on a GP 60-90 size ugly stick and it handles it well.

Buck 1856,

I to thought it was a toro ...at first. I also have converted many, many toros...great little engines. BUT, two things lead me to believe its not a toro...
1. the crankcase looks too shiny.
2. the ignition kill leads coming off the coil are on the side were as the toros had them on top.
3. The bottom right has a lug that is not on the toro crankcases.
I remember the good ol days (about a 2 years ago) when I was buying new toro powerheads on ebay for 25 each....
when I finish my ryobi 40cc conversion, I have a toro that I put "on a diet" I will post ..man is it light!!

The motor is from a MTD blower motor or Chinese clone of the Toro or Zenoah. It’s new and the flash back from the camera flash is why it’s so shinny.
I’ve been working on these and 2, 33cc Homelite conversion and hope to be able to get parts ordered soon for the final assembly.
What type of airframe would work for these motors? the 33cc Homelite.
Any Ideas on or suggestions would be of great help. I have some ideas but any suggestions or input would be of help.

I have a suggestion...keep the prop hub short as possible. It is the same engine I have that is in a video and some photos. The main bearings went bad. I noticed my leaf blower has kinda loose bearings from new. The one in the photo went back in leaf blower. Capt,n

I plan to eliminate the prop extension. This will shorten the placement of prop over 1 3/4 inches and make life more easy for main bearings. The hub that the prop seats against will have a short protrusion to center prop. This will also eliminate the bolt for prop. The crankshaft itself will have the threads for prop nut. seems like a plan! Capt,n

Have you tested your motor since you made the changes? Any RPM difference?

Heres a pic of my 25cc toro from ebay before isold it.Or before i converted it,ill have to post the pics and see what comes out.I bought these off of ebay and when i called the 1-800 number from the plastic shrouds to see how availible parts are for these the person actually said they where in the US,parts are easy,and there from toro and maybe a few other machines.The MB290 mac might be one.I still have the 1-800 number in my RC stuff[aeronautic files].
Well,i checkedmy files for the number and now cant find it.I may have sent it with the last motor i sold.I will agree with billzair though as this motors and ones from ebay where frm a blower as the throttle only ad 3 positions,and was a large black plastic piece with indentations for closed,idle,and wide open.
So heres the pics for Captn,and billzair is more than likely right also.
I also bought mine for $98.00 for a box of 4.Bought 2 boxes before he sold out.And i dont have any left.