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I just received the June 2008 edition of Model Aviation in which there is a very fine article on the construction and flying of the 1/2a Marval by Dan Berry. Contained in the article is a chart giving the weights of several competitive 1/2a engines. I will list them here incase you missed the article.
Cyclon .049: 68grams
Cox TD .049: 47 grams
Stels .049: 45 grams
VA .049: 44 grams
AME/Norvel .049: 38 gramsYou can see there is an ounce of difference between the Cyclon and the AME/Norvel. What would be interesting, to me, would comparisons of power between the five engines. I’ve been searching the web for this information, but haven’t found a thing.
I’m hoping readers of this post may be able supply the energy out put for some or all of these engines.
Stardust
Hey Stardust
Its a busy flying weekend. There may be some response after Monday.
I can tell you what I know.
The Cyclon makes more power. It easily hauls 300-325 square inches. The other engines will struggle with that much wing.
My VA MkII will turn the 5×2.75 glass prop at 31K. It turns the APC 5.5×2 at 27,5k. I like it better with the glass prop.
Stels and AME will approach or exceed the VA. AME had quality control issues, I think.
The TD would have less power. It would still make a 6oz Marval a potent machine.
Obviously, availability is an issue. It wasn’t when I bought the VA MkIIs.
That’s about all I can contribute.Will you be at KC in June?
Dan,
Once again a very good article. Maybe I’m expecting too much but don’t manufacturers publish something about out put in hp, or ergs, or Newtons? I would think it would be SOP along with other data. I will be in KC maybe I can keep track of my Mullivihill this time.Actually, I may be doing something a bit different this season. This is only season three for me. I have a 1/2a T-Bird with a Hornet up front and I’ve had some success on the bench getting it to run on pressure. A scary new world for me, but I’ve been greatly influenced by posts on this site advocating pressure and I decided to give it a try. Locally, we’ve had winds (15-25 mph) or rain and marginal field conditions so not many opportunities practice.
Stardust
I have a TD and a Cyclon.I don,t have any figures but the Cyclon is in a different league.It is much more powerful.It is even more powerful than my TD09.probably by a long way.As you may have seen from my posts elsewhere,I have recently changed to pressure feed.It is very satisfactory, especially with the Cyclon
Well, the details are starting to come in. I wonder just what is involved in measuring the out put of engines? The comparisons I’ve seen have to do with how fast (rpm) a particular engine can swing a particular prop. I hope John Lorbiecki will weigh in on this, I bet he has some answers.
Stardust
John has been in Muncie. he is gonna say—the Cyclon is the best. By a lot. Building to available power is a good idea. Do you have an engine already?
Dan is right…..Without a dyno, it always turns out that you take a “standard” prop and compare rpm. To be truthful, I never saw a small dyno for an .049- there must be one tho.
Another test is to look at thrust. Doc Anderson in the “olden days” had a unique deal. He took a pole, which was at least 6′ long and put a hook on one end. This hook and pole were suspended from the ceiling of his porch. An engine mount as attached to the floor side of the pole. Attached to that was a pull scale. He would then fire up the engine and read the pull on the scale. The long pole gave him a very large radius and free movement so that the fixture was basically taken out of the picture for accurate readings. Doc used this during his propeller development days- I really miss that guy!
Definately the Cyclon is at the top of the list of .049’s. I would put a Verbitsky folder on it, with the tips cut to 5.75″ diameter. The amount of thrust given by that combo verses almost an other .049 will put you at the top of the heap. I have heard alotta guys that have really screming engines but most of them are under propped and just make alotta noise. Look at what the F1J guys do and you will see models that have had a good prop, engine, airplane combo. The cost of the folder will be made up in that you will almost never break it. In 8 years of F1J flying we have broken only two blades, which we replaced.
Now the bad news. I heard a rumor at Muncie that the cost of the Cyclon has gone up almost 33%! There was talk that what used to be $160 which had gone up to $190 is now $300….Doug Galbreath told this person to just wait and see what happpens. If this is true, we may see fewer and fewer new .049 and .061’s being purchased…
Hope that helps a little- BTW- I actually beat Chuck Markos in F1A to take 1st- I hurt the engine on my F1C that I was goign to fly so didn’t get to play with that at all. John told me I can use one of the newest models at the next contets- Poti, Morris, Servaites, ya better watch out!!
John,
Thanks for weighing in. As I was reading how Doc Anderson was testing prop thrust, I didn’t quite get it the first time through. I was imagining the pole being pulled forward and up ward, through the arc, so that the results could be read like one of those wind gauges that pivot from the top. Too much engine and there are holes in the ceiling of his porch. Clever bit of experimentation however.
I did find a site that has something to say about F1J and F1P engines plus the Arthur’s point of view on setting up different classes of models.http://www.gregorie.ukfsn.org/freeflight/f1j/index.html
Stardust
If you look at the Cyclon review that Martin did, I think you will see some of my comments on getting older Cyclons to run properly….It is a good review!!
I found this information on Wikopedia. Perhaps more data will turn up.
“The Tee Dee was tested by Aeromodeller Magazine in 1962 and the output power was recorded to be .105 bhp (78 watts) @ 22,000 rpm with a max torque of 5.5 oz.in. at 18,000 rpm on 25% Nitro.
The modern Norvel AME 049 engine which has a ceramic coated aluminum piston outputs .2 bhp (150 watts)@ 17,000 rpm.”So, the AME turns out 2X the power of the beloved TD! WOW.
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