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-   -   prop size? (http://www.rcuniverse.com/forum/engine-conversions-92/2586398-prop-size.html)

Lee MRC 01-26-2005 01:07 PM

prop size?
 
Can some one assist me please? I need to choose a prop for a 23cc/1.6 ci homelite that I finally have been able to convert. I do not wish to fly 3/d or other compition. I would also appreciate any thoughts on plane sizes etc. wing and fushlauge dims. The aircraft that I wish to build will have either a low or mid wing. So not Cub like. I know that this is not enough info to make an approaite suggestion but perhaps get a descussion going. My main question is what prop? I am going to town and the hobby shop today, any help? Please?

Fly the airplane first Lee K5MRC

farley9n 01-26-2005 04:28 PM

RE: prop size?
 
Hi!
I can't advise you on props but I would like to know what this Homelite was out of and is it a reed valve or piston port engine? Thanks......Bob

w8ye 01-26-2005 04:44 PM

RE: prop size?
 
A 16-10 Dyna Thrust should work great on it.

Enjoy,

Jim

Lee MRC 01-26-2005 08:17 PM

RE: prop size?
 
The engine is from an ST-80 string trimmer that is about 25 years old.

Thanks for the info on the prop. I have a 14x10 that I was going to try, just to run it on the bench after completing the mods to convert it to aircraft use. Once again thanks for the help.

Please excuse the spelling but I am from Texas.

Fly the airplane first.

Lee K5MRC

Lee MRC 01-26-2005 08:20 PM

RE: prop size?
 
Farley9n, sorry that I did not reply to your question, but it is a reed valve engine.

Lee K5MRC

farley9n 01-26-2005 09:39 PM

RE: prop size?
 
Thanks Lee.
If you ever need any parts for that engine it's pretty much the same as used in the Homelite little Super 2 and EZ chain saws though the displacement gets bigger. I have a bunch of that syuff!.....Bob

w8ye 01-26-2005 10:06 PM

RE: prop size?
 
Select a prop to keep the maximum rpm in the 7,000 rpm range.

Enjoy,

Jim

tailskid 01-27-2005 10:58 PM

RE: prop size?
 
Try the following site for some recommendations:

http://www.zingerpropeller.com/Engin...on%20Chart.htm

Jerry

Lee MRC 02-08-2005 11:39 AM

RE: prop size?
 
Thanks for all the info. I really appreciate it. How does one go about sellecting a prop for a given engine rpm range without a lot of expensive testing or someone elses experience?

Also does anyone have any suggestions on aircraft dim's?

Sorry to be so slow to reply but this darn flue can really set you back, big time.

Fly the airplane first.

Lee K5MRC

w8ye 02-08-2005 12:07 PM

RE: prop size?
 
You try to get in the ball park with the cheep, Dyna Trust props. Then if you have money to burn or the need for even more power? You can buy a couple $50 props?

Enjoy,

Jim

Prop Nut 02-14-2005 09:22 PM

RE: prop size?
 
1 Attachment(s)
Hi Lee,

A great small gas engine plane would be the Fokker E.III Eindecker 90 by Balsa USA. It has an 80 inch wing. I have a converted Leafblower 25cc on mine. Works great and flys great. Easy build to.

Lee MRC 02-15-2005 10:00 AM

RE: prop size?
 
Does anyone have a reply concerning the Zinger 14-6/10 as a trial prop?

I do not want to destroy this engine with the incorrect size orop?

That is most likely an incorrect sentence but it may get my question across!

I will be trying this engine this week so any help would be appreciated!

Another portion of my enquiry is the proper size of the airframe to utilize this engine.

If anyone has a suggestion I would certianly appreciate it.

I am looking for sugesstions for wing span, wing cord, fuslauge length, weight? (spelling?)

I am reaqlly new at this , but I am trying to not make too many mistakes on my first try and any help that you can afford will be APPRECIATED, please reply with any positive or negative comments because they all count.

Thanks

Please excuse the spelling but I am from Texas

Lee K5MRC

w8ye 02-15-2005 12:40 PM

RE: prop size?
 
Lee I have several converted engines with one of them being a Homelite 25. It has a Zenoah 23 carb on it.

I can use a Dyna Thrust 16-10 prop and it turns 7600 rpm

Also it has had a Dyna Thrust 18-8 and it does 6900 rpm

Before I put the bigger carb on the engine, it would turn 7000 rpm

I've seen these engines on some of the larger 60 size planes but mostly on 120 size planes.

Get your engine running. Watch that it doesn't turn too fast. Getting above 8500 might give you trouble eventually. Running a prop that keeps the rpm below 6,000, your just not getting enough power from the engine.

It'll run with the 14-10 for your initial runs but it should run a good bit of rpm but not enough to hurt it?

The 16-10 should be the correct prop in the long term use when flying?

The Balsa USA Eindecker would be one of the best planes I could think of for that engine. There's two of them at one of the fields where I fly.

Enjoy,

Jim

Lee MRC 02-17-2005 05:24 AM

RE: prop size?
 
W8ye, thank you for all of your assistance with this project. I will give each of your suggestions a trial run and try to determine the best inviroment for my engine. I have several more, and different, engines to try before I either give up or succeed!

As an aside I can't help but notice your signiture, are you active on the air and if so what freq's and times? I have really been enjoying getting my orginal AM rig back on after about 25 odd years and meeting some of the same people that I flew with in Midland, Texas. It is amasing that after all of these years we still hold the intrests.

Again, thanks for the assistance.

Fly the airplane first

Please excuse the spelling but I am from Texas!

Lee K5MRC

tim220225 05-04-2005 11:00 PM

RE: prop size?
 
I just finished converting and bench running my Echo 23.6. Used a Master Airscrew K series 18/6 and turn just over 8200 with it a tad rich. Will be replacing the OS 91 4-stroke in my Balsa USA Eindecker with it. May try a 17/ 6 or 8 later on. SHould be real nice to run when I am done.

w8ye 05-04-2005 11:49 PM

RE: prop size?
 
Looks to me that you already have the correct prop? 8200 rpm is a pretty good sweet spot for your engine.


Lee MRC
Quote:

"As an aside I can't help but notice your signiture, are you active on the air and if so what freq's and times? I have really been enjoying getting my orginal AM rig back on after about 25 odd years and meeting some of the same people that I flew with in Midland, Texas. It is amasing that after all of these years we still hold the intrests."
I Don't get on the air anymore. I'm on RCU all the time. I sawed my antennas down. Still have a Yaesu FT901ZD and a Dentron MLA 2500 amp. I remember talking 48 states AM on 160 before they opened up the band. That was fun. I was mostly a 75 meter rag chewer. I have a ICOM 2AT all stuff from 25 yrs ago.

Enjoy,

Jim


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