Hi,

I posted this first in Q&A and didnt really get any usefull info.

My first gas engine was completed yesterday by a friend in my club. Its a 52cc conversion engine. [link=http://duropower.com/item.asp?PID=86&FID=3&level=1]http://duropower.com/item.asp?PID=86&FID=3&level=1[/link] They went up on their price since I bought it...I got it for $80 including shipping . What I was wondering is, how many pounds of thrust can this engine produce? When it was on the test stand it turned an old 20x10 Dynathrust prop at 9600 rpm. It weighs 6lbs with the stock muffler and carb (with will probably be changed).

I'm going to design and build a Biplane around this engine. I want it to be capable of performing basic 3D manuevers. What should my target weight be?

Here's some video of the engine.

[link=http://video.google.com/videoplay?docid=7063498753981003477]Running[/link]
[link=http://video.google.com/videoplay?docid=1899399485091143431]Starting[/link]

Thanks for reading

Zagi,
Here is the link for a weight chart. http://www.rcshowcase.com/html/chart.html Fifteen to eighteen pounds sounds good.
I think that you should try another tach. If you are getting 9K plus on a 20x10 you don't have to worry about static thrust.

Dave

Believe it or not that reading is correct, tached it on 2 different days. I trust the guy who measured it. He's converted more engines than I've ever seen. We were all kind of blown away by it (no pun intended). We think its probably underproped. Thanks for the chart, I think I can get it under 18lbs. Its a profile so it shouldnt be terribly difficult.

I just found this...According to this chart...The engine will produce 35lbs of thrust with a 20x10 prop at 9000rpm? And 45lbs (wow) with a 22x8? Correct me if I'm wrong...but doesnt 3D flight require that the static thrust be at least double the wieght of the plane?

I did this conversion and didn't believe the RPM numbers so got a buddy's tack to verify the numbers. The prop was an old Dynathrust 20-10 that I had in a drawer and had never used. Only good for stiring paint. I would like to see what this engine will do with a good 15mm WT carb and an APC prop. With this kind of performance I will buy one of these engines for a 1/3 scale Cub I'm planning.

When i tryed to get this engine a few months back Duropower told me they could not get them anymore.

I got that message too but I called them on the phone, They told me it was backordered....It took me four months to get mine but it finaly came in. It was definitely worth it.

Thats good to know, maybe i will try again. I have the 32.6 cc it is a power house too, just put on a prop hub and go, run mine on Ei

Have you tried any other props?? I am not saying I dont belive you but those numbers are pretty amazing.

I would like to pick one up. I have a home made profile plane that is 15lb on the button that a 45cc homey power very well (unlimited vertical). I really want to try that 52cc from what you say it is WAY more powerful than my 45cc engine. I can only get 7200 rpm with a 20X6 prop.

This one is going to go on a profile also. I don't belive any other props were tried on it, but when I get it mounted on the plane (which isnt built yet...I'm going to start week after next most likely) I'm probably going to try the Zinger 22x8 on it. ...Well, what I would REALLY like to try is a Carbon fiber Mejzlik 22x8 ...I just cant make myself pay the $56 for it .

Hmmm 10HP from a 52cc better call DA and sell them your secret.

It actually weighs more than a DA 100 so I somewhat doubt they would want it

The 22-8 zinger is not much better than the paint stirrer you already have. Spend the extra bucks and get a real prop, like a Meinz. MSC, XOAR, or NX.
Z