the Wasp

My Feedback: (1)

Oh I see now, I'm getting PMs that are telling the truth,, you guys should be ashaned of yourselves,, you not going to make that much money on 1 Engine

Konrad

As I appear to have offended you I'm being very careful.

Again I'm just try to see things as you do. Like I said to 'my' way of thinking the reason you gave in support of your recommendation "rated at 17K rpm" was lacking. As you aren't the only one that has used this kind of statement, I thought I ask what you meant. It is my hope that this line of questioning will make the statement clear to me and the OP if he too has question as to its meaning.

I'm on this form to share information. This means give what I know and learn what you know. It has never been my intention to offend. Now I do admit I have view that are contrary to the norm. Now many then think I'm assaulting their view when I ask for clarification, this is not the case. I hope I have never said straight out that anybody's view was wrong. Now I might give a forceful argument contrary to one's view, but I hope to never say you are wrong or don't know what you are talking about.

All the best,

Konrad

the Wasp

My Feedback: (1)

I see now, I'm getting PMs now,,

you guys should be a-shamed of yourselves !!
is the profit on 1 engine so much that it is worth it for you to make people look bad and aggravate people in such a way ?? I hope so

Jim

Konrad

Profit?

I make no sales. Not even from my collection of engines. (Ok, nobody would want them).

All the best,

Konrad

Konrad

Jim,
Who ever is PMing you with that information is engaging in sloppy thinking and making slanderous post. I'd recommend that you report the PMs to the moderators for proper action.

All the best,

Konrad

controlliner

"I know the OS 50 Hyper Heli Engine will turn 17,000 and 18,000 RPMs (and so do the thousands of other Heli owners that use this Engine) , I know because I have set my Speed Controls at those RPMs with this Engine, and I also know that I ran these RPMs on 15% Nitro with the Weston Mini Heli Muffler and 20% and 30% with my MP2 Muffler.. "

This engine will spin up that much in a heli with a flywheel and pinion turning a spur gear, BUT I seriously doubt it will spin an 11inch prop at the same or close to that RPM. I just don't think the crank timing and Xfer port timing will allow it to perform according to the sweet spot on the power curve.

the Wasp

My Feedback: (1)

no one said what prop


Konrad, no one said YOU do make money on the engines, with what I know Reps don't make money, they get their discount, and here I'm not saying you are a rep, maybe your just helping out a friend, and I rather report you

controlliner

If you use a 10 inch prop or less the lower end of the conrod may suffer. You may not find a 10 inch or less prop with enough pitch to sufficiently load the engine to avoid a similar "shaft run"

Konrad

Jim,
Are you suggesting that the "rated at rpm" meant that the engine is self regulating? That is, that as the power drops off as the engine over speeds that it will hit a rpm point that the rpm will not climb, even with no load (a shaft run). See non piped plot graph to see the power curve dropping as the engine is over sped (19K rpm).

Also note that a tuned pipe can and does actually act like a gear box allowing one to custom fit the torque curve to ones needs. What is shown is the use of a very long pipe to move the power band DOWN into the 10.5K rpm band.

A pipe adds nothing to the ultimate rpm limit of an engine.

All the best,

Konrad

Konrad

Report me for what? As to engines, I make my own. As there were very few that I could use for my intended application.

Me, with friends in the model engine business, now that is a good joke. I strive to drop the veils of ignorance when it comes to engines. This is often at odds with most OEM engine marketing departments.

All the best,

Konrad

the Wasp

My Feedback: (1)

Konrad,, you are acting like my Daughter again and reading into things, and I know about the other posts,, I'm only suggesting an Engine,, again, all I said was it is Rated at 17,000, and again> I did not say it was better or best or fastest, or most powerful,,

and again> I suggested this Engine because,,

A) I know it is more powerful than a Standard 46 or 50 size Plane Engine

B) there are many used ones for sale at lower prices than a Standard 46 or 50 size Plane Engine will cost new

so I suggested it,, you on the other hand are trying to make me look bad by suggesting I said things I did not say !!

Konrad

I'm saying no engine is rated at any RPM. They are rated at a certain power and this power happens at "X" rpm point. So saying that an engine is rated at XX RPM is meaningless, and gives NO indication of performance! I think that is what I and the other engine "experts" are saying! Your daughter excluded!

This has nothing to do with your recommendation of the OS 50.

Now if I'm in error please correct me. I'm just looking for clear thinking with regard to RPM ratings and Pipe usage. I admit your statement is rather fuzzy in my mind.

How you look is of no concern of mine, but to your daughter I understand.

All the best,

Konrad

TimT2000

My Feedback: (1)

[quote]ORIGINAL: w1nd6urfa

I was given a TWM Nemesis which needed some minor repairs, and now I need a .50 2-stroke to match

I mostly fly warbirds on Saito 4-strokes, so I need some help here. Webra and Irvine look good, do they have any bad habits such as difficult break-in or tuning? Do they need any special fuel?

TIA
Nick




<span style="font-size: larger">How fast do you want to go? A Jett .56 will turn a 9x8 apc at 18,300 rpm on the ground and around 20,500 rpm in the air,,
maybe a little down hill. That will get you to the 150 mph club if you want it. If you are good at tuning racing engines, the Jett
will do this all day long for years. Put one of these on a Q-500 plane and have some fun..


have fun,

Tim

</span>

Quikturn

My Feedback: (12)

There is a NIB Rossi 53 2 stroke on $bay right now. That would be a good choice for the Nemesis.

DarZeelon

More than anything else, advertising HP @ rated RPM is a 'pissing contest'...

Nearly anyone can say someone his XYZ .50 engine produces 6 HP @ 25,000 RPM...
The only acceptable proof is the ability of a given engine to spin a given prop, on specified fuel, at a given RPM.

From this number and with the known (calculated from empirical, observed results with a dynamometer) power absorption of the propeller; the output at different RPM levels can be quantified quite accurately.

These actual HP numbers can be plotted into a HP graph; and with this curve the HP peak (and the RPM at which it occurs) can be estimated quite accurately.

Dub Jett does this, but only specifies a claimed number for one prop size.

For example, the SJ .46 spins a 10x6 APC @ 16,500 RPM. This calculates to 1.758 HP; and different other sizes can be clocked to plot a graph.

earlwb

Since the OP is in Greece, someone else had mentioned the West engines. The 52V1 or 8.3cc for High speed flight would be the way to go..
http://www.westonuk.co.uk/westonuk2_021.htm
West is sort of like the Eurpopean version of Jett engines.
I liked their 5.8cc engine that had the neat finned backplate mount too.

DarZeelon

Quote:

ORIGINAL: earlwb

West is sort of like the Eurpopean version of Jett engines.

I beg to differ, Earl.

West-Eurotech engines are by and large based on Webra engines; and are made from their parts/components (mostly).
Their most prominent engine; the '[link=http://www.der-schweighofer.at/public/files/21615.pdf]50 V1[/link]', is a souped-up Webra .50GT, with the same ABN P+L set.

West-Eurotech is to Webra, much like Alpina is to BMW, or AMG is to Mercedes-Benz.


Dub of Jett Engineering designs and makes his own engines, based on no-one; and their parts are produced independently (some with Israeli made [link=http://www.iscar.com/]Iscar cutting tools[/link], now owned by Warren Buffett).

earlwb

I stand corrected. Thanks for the info. Yeah I see it now, they are using Webra parts.

Wingspam

The 55ax and a 10x6 prop will get you right at 100 mph, be sure and take the baffle out of the muffler.

cordell staker

I have a NIB o.s. SX .50 that you might talk me out of. it's listed in engines for sale. i just don't fly planes that small any more.

RCER88

My Feedback: (25)

The OP asked for suggestions. Now I am going to catch holy hell for this but here we go.

A friend of mine has a revolver similiar airframe to the nemsis. He has flown his with two different engines.

A Magnum 52 with a Rossi mini pipe and Rossi 45 with mini pipe. Both give that revolver plenty of speed without risking "Vaporization" of an ARF airframe in flight. Using a 10x6 APC prop. He "smoked" the 52 on a lean run that is why he went to the 45.

It depends on how much money you want to spend and what is available to you locally. He preferred the 52.

I admit I have NO experiencee with the some high end engines namely Jett, Webra, but I do have Rossi's and I love them. I have 45's, 60's and 61's. My 61's are rear exhaust used in pattern ships.

The final decision is yours. I like the Rossi's for there performance and reliability and I do not have to run high nitro to get good performance.

earlwb

hey, nice going. i always like to read or hear about guys doing what you all did. Nice to know the .Magnum .52 can turn up some rpms.
More power to ya.


I think the problem today is that the big bore 50's and above have evolved more for turning large props well, so they can reduce prop noise and also with lower RPMs the mufflers help quiet the engines better too. So thus the manufacturers have been boring the engines out more and more to get that marketing competitive advantage. It is where the fickle modeller goes into the hobby shop and sees a .50 engine and a .52 engine, he'll very likely buy the .52 as it is perceived to be more powerful than the .50.  So we wind up seeing where the engines keep getting bored out ever more.

But there are performance engines still out there, even some good deals on older engines from when RPMs were more the rule and noise, and if someone was really wanting to smoke the crowd at their flying field, they'll have to pony up the bucks for the real high performance engines.

hsukaria

Oh Boy!! It didn't take long for this forum to degenerate into another argument.

I am relatively new at RC hobby, 5 years only. So I will not be able to offer anything new that everybody here doesn't already know. But I will open my big mouth and make some comments and a couple of wishes anyway:

- The OP did not mention whether he wants to fly for fun/sport or flat out competition. That would make a big difference. But I think that is a good thing because by leaving the topic fairly general, we have been able to get a lot of good info from experienced guys.
- I have an OS 55 AX and it is more tuned for larger props. I understand that the older OS 50 SX is designed for higher top end rpms. Being that this plane is a racer, something to consider.
- I have an old Irvine 40 and it has been incredibly easy to use. I don't think it is designed for high speed, it loves to spin relatively bigger props and slower speeds. I used it with a 12x4 with great results. But that won't fit this application.
- I have a Quicke Great Planes Viper I bought used with a Super Tigre 40. I had concerns about a Super Tigre 40 on a quickee, being that it is a ring engine. But it is a blast for fast fun flying. And it is a low cost engine.
- Even by keeping the engine output testing conditions restricted to controllable parameters, there are still many variables that would make comparing engines from different manufacturers a bit vague. The fuel could be different even with similar % nitro, the engine run-in/wear could be different, temperature/humidity/altitude, personality/attitude/honesty of the person testing, possibly the location/characteristics of the fuel tank/system, etc...
- I wish that there could be a standardized testing procedure and apparatus that all the engine manufacturers submit to so that a comparison between brands can be made. But that would not help with characterizing the durability, ease of use, reliability, service, and other parameters that are more subjective.
- This might sound silly, but the OP got this plane used. The engine cowl has already been carved out for a previously mounted engine. So unless the OP wants to buy a replacement cowl or carve more holes/openings out of the existing cowl, he may want to put something that would limit/reduce the amount of carving.

the Wasp

My Feedback: (1)

""but the OP got this plane used""

exactly,, and it was damaged too,, so it was my thoughts that Nick didn't want to put a lot of money in it and buy a $200, $300 Engine, and I knew he could buy a used Hyper 50 and it would have more power than the average 46/50 standard Plane Engine,,,

b b but, there always have be that "one in a crowd" that has to do what they do

sorry Nick !!!

airraptor

My Feedback: (66)

any stock unmodded 45-small case 60 two stroke engine will be very close in spped on this plane. Jett 46-56 engines will get you about 10-15 mph over these other engines. so over all your looking at 85-115 mph with any of these engines. so pick the one you like best and have fun.