lewdfinger

If I hit my target weight this winter (15 pounds to go!) I made a deal with myself to switch a ZDZ-80 out of my 33% Aeroworks Edge 540T in favor of a 100cc twin. I like what I've heard about the new 3W - 100's, as I can get one from Europe substantially cheaper than a DA or BME. I have considered the ZDZ 100 boxer, but it sounds like the 3W is going to have more snarl for the money.

Anyway, does anyone have some real-world experience, a' la comparison of the stock 100 B2 vs. the QS? Better to use the cash for tuned cans?

KD

fryfly

My Feedback: (8)

go ahead and spend the money if you have it you will pleased in the long run with your choice.the tuned cans boost the horsepower a little but do more to quiet it down.The big kick with the 3-w motors are that in Germany there is a BIG issue on noise thats why these motors were specifically designed to run at lower rpm's.3-w puts out the same if not more raw stump pulling power at approx 6500-6800 rpm's as any other engine out there turning 7500-8000 rpm's!!!!! this doesn't mean the 3-w's won't turn that,I run a 85 twin with a 26x8 mens prop on a 33% 26 pound laser that absolutely RIPS !!! the QS series times the exhaust ports a little better than the regular motor series plus they tweek out the carb a little more too! well worth the extra money.one word of advise find a prop the works good in the 6800 rpm range and then drop down one step in pitch size and the motor will come alive,before you do this run atleast a gallon of fuel through it to make sure the rings get a chance to settle in a bit.looking for a motor here in the states go to Cactus Aviation out of Arizona, Regardless of what anyone says Bobby knows and personally deals with and even goes to Germany to the factory on business,He's the only one who deals solely with 3-w no one else out there can say that, and his service is #1.Going anywhere else is like taking your chevy to a ford dealer for service,you know they can do the job but it just doesn't seem right. Go to Cactusaviation.com or call Bobby yourself at
520-721-0087 tell him Terry F from Battle Creek Mi. sent you!!

Jemo

My Feedback: (5)

Quote:

deals solely with 3-w no one else out there can say that

??????????????


http://www.aircraftinternational.com/

fryfly

My Feedback: (8)

sorry I guess that was a bad choice of words! I meant to say that Cactus Aviation only deals with 3-W motors and that's all.They don't carry parts for other engines such as Desert Aircraft ,Brison,or carry kit's from other manufacturers.Aircraft International does.

Jemo

My Feedback: (5)

Gerhard Stejskal of aircraft international was born and raised in Germany...........So there......

fryfly

My Feedback: (8)

Cool! makes me feel better!

Jemo

My Feedback: (5)

fryfly

All kidding aside. That was a good explanation of the QS series.
Thanks

Diablo-RCU

My Feedback: (1)

I get mighty confused about all these claims of superior torque at lower rpm via special porting etc. I don't see any difference in the way a 3W or DA or ZDZ or BME runs with various props. Everyone I know is propping the 80-100cc motors to turn 6,000-6,600 rpm. Sure, some can turn a bigger load prop in that rpm range, but it's horsepower (not torque) in the that rpm range that determines how big a prop it will turn. A higher torque peak at 4,000 rpm (for example) is only useful if you plan to prop the engine to turn a max of around 5,000 rpm. Prop loads are exponential with rpm - this means that the load increases rapidly with higher rpm. It also means that engines don't need lots of low rpm torque because it's easy to accelerate the prop through the no or low-load range to higher rpm when you open the throttle.

Antique

My Feedback: (4)

AMEN !!! Thanks, Diablo.....
That's why propping a Zenoah twin for 6000 rpm doesn't work..The INSTRUCTIONS (What are those for ?) say to use 8000 (or more) rpm to get the power....Duhhhhh..................

fryfly

My Feedback: (8)

good point! but just a little first hand experience, and this might be just me and my observation.I fly a 3-w 85 twin rated at 7.9 horsepower on a 26 pound laser with a 26x8 menzj prop turning about 7200 rpm's my buddy flies a lanier staudacher at 25 lbs with a BME 102 with a 26x10 mezlik at about 7500 plus rpm's and as far as I can tell they run exactly the same performance wise.his plane is a little faster because of the weight and pitch size but who needs speed unless your racing! I guess I'm a little partial because I only fly 3-W but after seeing Zenoah's,Brisons,BME, and ZDZ's fly I'm glad I made the choice I did in the beginning.Only one other point I would like to make is I fly and am leaning more these days towards warbirds and I think with the weight of some of these babies these days and all the little extras you can put on the under side of them the 3-W is the most logical choice for smoothness and with the torque the motor has I can actually run a more scale size props without the motor bogging down when you perform a manuever,it's like running your lawnmower into deep grass and listening to the motor bog down then picking back up after your through it, I feel the 3-
w motors with the low end power they produce don't lose rpm's when you load them up like that,it's like they have a built in invisible govenor that makes them perform the same through the whole rpm range.there really is no need to produce 8000 rpm's these engines don't fall backwards in rpm's or power when you make them work,but like I said I might be a little partial.

Diablo-RCU

My Feedback: (1)

Say Fryfly:
Try another prop experiment. Use a Menz-S 26x10 on your 3W-85. Have your buddy with the BME-102 try the same prop. You could even try a Menz-S 27x10, that will really load down your 3W, but your buddy with the BME will really like it. The BME should turn the 27x10 prop around 6200 rpm. The 3W will probably be around 5800 rpm.

fryfly

My Feedback: (8)

your exactly right but what's your point? I'm just stating that my motor is approx 18cc smaller and pulling the same size airframe with a pound more weight and pretty much keeping up with a larger motor from a different manufacturer that's all. I'm not putting anybody down just stating a fact that I have personally witnessed.My motors run so good theat the guy I referred to with the other plane has also in turn started running 3-W on his warbirds I guess it is really personally preference. food for thought!!

T_Hill

fryfly,

What he's saying is it's not far to compare them on different props. Props make a big difference in performance. You can make a strong engine look bad by choosing the wrong prop. Mezlik props are not exactly known for power and that's what you're seeing in your example.

Tracy Hill

fryfly

My Feedback: (8)

your right !! propping makes a big difference all the difference in the world but I was originally talking up 3-W because of the very high torque they put out at lower rpm ranges.In Germany they have a big problem with noise thus the reason 3-W came up with their own head design and rear induction to battle the problem of getting the horsepower they needed to fly a plane at lower rpm's keeping the prop noise down to a minimum.I don't know maybe it's just me but if you look at every other engine on the market today and I do mean every!!!!!! D.A.,Brison,BME,first place,the wolf preditor,they all have one or more things in common the D.A.,Brison ,wolf preditor,BME damn near all have the same crank case style made from the same basic manufacturer and most of the heads on some of these guys have extra cut outs with little caps covering them up which tells me that particular head was used for some and most likely many other applications such as chain saws,industrial cut off saws,etc.and the head on a 3-W has a noticeable difference truely made for their own crank case and the crankcase which is the biggest difference of all doesn't look like anything else out there,Don't get me wrong all the other engines out there on the market today all work and work very well other wise they wouldn't be in business,but the point I have been trying to get across is that if a manufacturer goes through all the trouble it has to keep the noise level down to a minimum by producing an engine that puts out the same torque at 6500 rpm's that another engine puts out at 7500 to 8000 rpm's with the same prop or bigger I'll go with the big block stump pulling power of the 3-W any day of the week.As far as I'm concerned the rpm's don't mean squat if you can't keep the rpm's where they need to be to do the job again this takes us back to the lawnmower theory in the deep grass,if you can't keep the r's up in deep grass your not going to cut much grass!!

erjpilot

My Feedback: (4)

Do you even know what a DA-100 looks like? Or have you ever owned one? The fact that you put a DA in the same class as a Brison, First Place, Wolf Preditor (All singles except for the Brison 4.8 & 6.4) is purely insane! If anything the DA is more similar to the 3W than anything else. I guarantee that a DA will beat a 3W in both Torque and RPM "any day of the week." I own both DA and 3W. Both engines run great with the exception of the normal 3W gurgling problem during knife edge and inverted flight. The DA is just an all out better running engine IMHO. Take it for what it is worth, but don't put a DA in the same class as a "weedy" conversion (if such a thing really exists, depends on your point of view) because it is not even close.

fryfly

My Feedback: (8)

sorry you feel that way but yes they do all look alike the D.A.'s crank case does look almost exactly like the brison,BME,and Fox crank case except it has a cylinder on the other side,and as far as the cylinders go they are sachs dolmer heads or a reproduction of,
and most of the other other engines (I don't know about your D.A.)
all use Walbro carb's instead of Tillotsen because they are about half the price!!!!! Yes the D.A. does look more like the 3-W because it has 2 cylinders one on each side and has the same kind of intake system but not exactly because 3-W has a patent on their internal workings as far as the crank cases go they are machined and look almost exactly like everybodys else's with a few minor corners rounded here and there just to say they are different!!!!! sorry but only 3-W can say they started from scratch and never copied anyone else's design or used the same manufacturer for their heads or casings, all components were made to fly model airplanes not cut weeds or logs!!!!!!!!!

fryfly

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Oh one thing I did forget to mention and this I appologise for is that D.A. does design their own cylinder heads but the thing is they are designing them around a copy of someone else's disigned crankcases!!! which are machined out of a solid stock of alluminum just like brison and fox and BME, 3-W are cast from a mold like a big block chevy or ford and built totally around their own designs

Antique

My Feedback: (4)

HORSEFEATHERS!!!!!!!!
Last time I looked the large 3W engines have WALBRO WGA7 carbs, not Tillotsons. Twice the cost does not make a better carb...
The WALBRO WGA7 is made for a CHAINSAW...If 3W really wanted to get rid of the mid range problem they could have WALBRO calibrate a carb just for them, as Stihl does for some of their chainsaws..
I seriously doubt that 3W could patent the internal workings of an engine...I work on them every day and have not seen anything different inside, except that 3W cranks are too hard on the end so that sometimes the threads break off..That's real progress....
If you knew more about 3W you would know that the early engines used commercial parts, just like all the rest...
The 3W 60 had a crank made by Husqvarna, and some of the cylinders had plates to cover the piston port intakes, just like all the rest...
Crankcases ?? The DA cases are machined from 7075 aluminum,. way stronger ( and more costly with closer tolerances) than the thin cast cases on the 3W..I have seen some 3W cases with pinholes in the castings, and leakage under the cylinders where the CAST cases didn't quite fill the mold....
Take the reed assembly out of a 3W and compare it to a DA..EXACTLY the same part.....
Get your facts straight....
BTW..The heads you are talking about are actually CYLINDERS. A head is something that bolts on the top of a CYLINDER....
Show me where anything on a 3W is patented...

Check out some of the 3w engines out there..You'll see that many of them are using DA ignitions...Or just the caps, which are better than the 3W caps....
Who is doing the copying there ??

fryfly

My Feedback: (8)

the facts are in and yes 3-W
has a patent on some of their designs especially the 3-W 50 thats why D.A. is having trouble with theirs they don't have it on the market yet because they can't figure out how to keep the darn thing running like a 3-W 50 and keep the crank in one piece!!!!! I don't know what kind of 3-W engine your running but I have never had a burbling problem with any of my motors.you must not know how to tune them or something because I have never experienced that! Anyone that flies 3-W can tell you that the linear response on their motor is untouched by all !!!!! especially with scale modelers who use 3-W and who cares what kind of alluminum is used it's still looks like a brison BME and Fox crank case chances are they are all made by the same manufacturer or by sister companies anyway and your probably right some of the larger motors might have Walbro carbs but that's probably to keep the cost down a little bit,everyone knows that a cadillac cost more than a chevy this way it helps everyone try to get into the cadillac of motors 3-W !!! and hey all kidding asside I have enjoyed this little endevor don't know when I have had this much fun on line in a long time I appreciate the knowledge you have shared with me and others.This is truely a great hobby we all participate in and these kind of forums really help to evoke opinions,beliefs,and facts each and everyone of us are here for the same reason because we love to fly model airplanes and we all have our favorite equipment I know I do!!! thanks rcign it's been fun.and by the way if there wasn't a 3-W motor out there I would be flying D.A. or a brison!!! they are both excellent choices

Rcpilot

My Feedback: (78)

So, from the tone of this discussion; I get the idea that you guys think weedies and chainsaws are junk.

I have no idea. I'm about to do my first chainsaw conversion. I'll bet I can get it going for UNDER $300. It's a 35cc. This will be my first gasser.

I think that there's a lot of hype about buying brand name engines. Everyone knows that a BME 44cc. is really just a Poulan chainsaw thats had a bit of millwork done to it. And there are folks who belive that the BME 44cc. is a great engine. I'm sure it is. But you can't say that the Poulan chainsaw engine couldn't be just as reliable and strong as the BME. I can say that a Poulan conversion will be a lot cheaper than the BME.

Like I said, I have no idea if the chainsaws and weedies perform as well or not. But, for a savings of about $150-200- I'll give it a try.

Someone is going to chime in and say, "You get what you pay for."

I'll argue that you just might get MORE than you pay for. We'll see.

Fact of the matter is- some engines run better at high RPM and some run better at low RPM. Who cares- prop the engine for max HP and run the snot out of it.

Antique

My Feedback: (4)

A simple question..Where do you get your DA information?? I have known both Dave Johnson and Bobby Wilson, long before Dave was making engines and Bobby was his employee.I will give him a call tomorrow to find out about keeping cranks in one piece...Or keeping it running like a 3W 50..And the patented (?) 3W 50 leaky reed valves that let fuel come back out and onto the firewall...
Rcpilet..Right on...
There are people who rely on and believe Hype...
The first giant scale engines were chainsaws, and most still use many of the parts...
Just because an engine costs more does not mean it's any better....
Who would ever have thought a 50cc engine would cost over $500.00 ???

T_Hill

fryfly,

You may be the only person I've ever heard trying to claim a cast crankcase is better than a machined one. 3W uses castings because they are cheaper. DA didn't design around someone Else's crankcase. Rear induction isn't used to get more low end power, it's used to decrease intake noise. Your low end torque is also nonsense and easy enough to disprove by proping both engines with heavy props. It was something 3W made up when they couldn't make the same top end power as DA. 3W, DA, and ZDZ are all designed from the ground up as airplane engines.

Tracy Hill

BBW Walt

My Feedback: (11)

It is funny just how far the responces to some questions go.

Antique

My Feedback: (4)

There are flyers who just have to get the latest hyped up engine they can find..Chainsaws and weedeaters are definitely not junk...A Husqvarna(or any other brand) chainsaw will run for 2 or 3 years, cutting down trees in the worst possible environment, before requiring any service...Even the lowliest weedeater, a $50.00 Ryobi, will outlast any plane or planes it is used on...
Regarding converted chainsaws and weedeaters, you get MORE than you paid for if you can do the work yourself....

erjpilot

My Feedback: (4)

Fryfly,
I am not quite sure where you are getting your information on the carb selections. I had a 3W-78 twin that had a walbro carb on it and two 3W-80 twins that both had Tillotsons on them. Your arguement that Tillotson is better than Walbro is a bunch of hogwash. Both are great carbs and both were not designed specifically for airplane engines, but for small gasoline burning 2-stroke engines in general, i.e. chainsaws etc. Your engine tuning prowess must be excellent since your 3W doesn't gurgle at mid range in knife edge and inverted flight. Your new 106 may actually not have this problem since 3W designed that motor with a new reed block and modified carb to actually try and alleviate the gurgling problem. I have not owned one of these new generation motors as of yet, but all of my previous generation motors and every one that I have seen fly at my field have had this problem. Last, but not least, just who is this "someone" that you refer too, that DA is copying the design for their cylinders and crankcases? Unless I am totally blind and onesighted, my DA-100 does not look at all like a Brison, 3W, etc. Please answer this question for me.