Goldie

ZDZ 50....A REAL LOSER

Hello everyone..... After the last couple of months of pure hell I wanted to make a few comments here so no one else would make this mistake. Let me begin by saying up until now I have been a HUGE fan of ZDZ... (and apart from the ZDZ 50 I still am). I live here in Denver where with this elevation we NEED all the power we can get..... A couple months ago I decided to put a ZDZ 60 on my Aeroworks 29% Edge, after seeing how well they perform. After pre-paying for it and waiting for a month for it only to find out that ZDZ did not get a shipment of them as they were suppose to and it would probably be another 6 weeks befor one came available I was talked in to going with a ZDZ 50. I did a lot of checking on the specs of the 50 befor getting one and thought I was ok considering how close the 2 were suppose to be. Also I thought if worse came to worse that I would just remove it and put it on my World Models Extra (81 inch, 15 pound plane). After several weeks of trying everything to get the power out of this engine we all gave up and decided to just go ahead and put it on my Extra. To my unbelievable surprise this engine is not only a dog on my smaller Extra, but a 'DOG WITH FLEES" I know that a lot of people are thinging "he must not be doing something right".... believe me this is not the case. I have had some of the best engine people here in Denver working on this, and the engine is doing EXACTLY what it is suppose to do, it just has no "poop" up in the air. We have experimented with everything possible.... fuel...oil....timing...props.... and a thousand other things including cuting the muffler (bison) ends off to pick up a couple hundred extra rpm's......... The sad part is the engine is performing EXACTLY the way it was suppose to.... I'm turning a pro zinger 22 x 8 prop around 6850 rpm's....... and the engine sounds and runs great, but the vertical is 100% NON EXISTENT and the power just isn't there..... It is a sad shame that the moki 210 I had on the Extra befor is twice the engine. Today I begin the task of removing the ZDZ and turning it in to a VERY expensive paper weight....... I also intend to call ZDZ (which I find to be a great bunch of folks there) and trying to exchange this very poorly designed engine for one of there 60"s........ Please dont get me wrong, I am not a ZDZ basher, on the contrary I still believe the ZDZ 80 and 60 are two of the best engines for our hobby, but this 50 has been a pure nightmare ( Sorry everyone, I just needed to vent some frustration here in Denver... take care everyone.... Goldie in Denver.

us020140

My Feedback: (28)

I just started using a ZDZ 50 in a Randy Navarre Staudacher. It seems to do well for an engine that isn't broken in yet. I'm hoping that after a couple gallons of fuel I'm not having the same experience that you describe. Is anybody else out there as unhappy with their ZDZ 50?

Kris^

My Feedback: (1)

Perhaps a propellor change is in order, to increase in-flight thrust. . I'd recommend going to a 21-10 menz-s as a starting point. It will possibly pick up a little rpm, and the higher pitch will help with both speed and energy once the plane is airborne. 8" pitch props are great for low-speed stuff, takeoffs and down-line braking, but if you want the plane to get some energy and GO, you need higher pitch. But you don;t want to lug the motor down, so a 1" diameter reduction would be in order.

One other note. . the pro-zinger is a thinner and narrower blade than the Menz, and with a thicker airfoil on the blade, as well as a touch more overall area to help grab air, I'm sure the Menz will be much more efficient and will increase your performance.

Don't throw in the towel yet. . You need every advantage you can get at higher altitudes. . perhaps a prop change will do the job.

Kris^

Diablo-RCU

My Feedback: (1)

I think your muffler is the problem. DH says this motor is ported for a big can or tuned pipe. He's got the experience checking out these motors with various exhaust systems. Try the Krumscheid 70cc can with a long header. The results with the Bisson pitts are luke warm. Check out this link.

http://www.rcuniverse.com/showthread...ighlight=zdz50]

fancman

My Feedback: (16)

Hey if you've only ever tried one prop on your engine you've missed the boat. I doubt seriously the pro zinger is the right prop to get what you want out of that engine. I'd be more than happy to send you $10.00 for that paperweight.

Merv

Flyfalcons

I've flown the sme combo ZDZ50/WM Extra with a Mejzlik 22x10. Vertical is insane.

aerobat66-RCU

My Feedback: (13)

I agree with Kris^ on the prop. I had a BME 44 w/ a 20x8 Pro Zinger on a 15 lb. plane. The performance was pathetic. I couldn't go 300' vertical after pulling up from full throttle level flight. I put a Menz 20x8 on it, and it was like night and day. It felt like I had put a 60cc engine on the plane. I broke that prop, and put an NX 20x8 on it, and enjoyed the same performance. IMO, the Zingers belong on smaller engines, particularly glow engines.

John

rcflyguy_26

My Feedback: (8)

I have also found that the pro-zingers are pretty bad. I would try a 3W or a menz before you sell the farm.

Later, Scott

JB Rekit

My Feedback: (3)

I am sold on Mejzlik. I know we are dealing with different sized engines but having put 3 different props on my DA 100 the Mejzlik has a considerable greater upline and better downline breaking with about 200 less rpm than a 3W wood prop did on the ground.

I say try a 21x10 Mejzlik, Menz, or Bolly (Haven't tried a Bolly but have heard good things about them.) and see if that doesn't make a world of difference.

SHINDEN

My Feedback: (10)

Hi All.
I have been flying my SIG EXTRA in Calgary 3500ft altitude with ZDZ 50 (about 50 flights), 15lb, truly unlimited vertical with 2-3 snaps on the way up, prop used BIELA 22x8 or Menz 22x8 or BIELA 22x10.
Tested ZDZ and DA, they are within 200 rpm of each other on BISSON muffler.
No complaints against ZDZ at all.

Regards Jack.

rmh

We are at aprox same altitude as Denver -(Littleton)
The ZDZ50 works justfine here - I checked out another ,last wek at the field for a guy- who had his mounted in a World models 330 -same size as the GP model - anyway -he had it overpropped and was using the Pitts Bison muffler -stock-new engine.
switching to the Bambula 20x10 -it worked and flew the plane very well - turned over 6900 -which is reasonable.
The engine was designed for use with can/pipe systems - where it really blows the others away -
I think it is also pretty much the same power as other 50's on the small muffler.
I never run the in cowl stuff on my own models . by choice.

Kris^

My Feedback: (1)

Lets see. . .a ZDZ50 n a bambula 20-10. . on stock muflers is about 6900. . whereas a DA or BME 50, with a 22-10 is in the 6800-7000 rpm range right out of the box with the Menz 22-10 and stock mufflers (numbers from both manufacturers).

Come on Dick. . . . . .

rmh

Chris - Those numbers from "both mfgrs" were not on the Bisson muffler - correct?
Also, I am giving numbers at 4500 ft altitude -
Using th same setup that ZDZ uses (JMB small cans and a very short header which was part of their setup as far as I know )-I get almost 7000 on the MenzS 22x10 - and very quiet.
The ZDZ 50 was designed for open can and tuned systems -
I have noted that -right from the first time I ran them.
On a tuned setup - the power really goes up
Why the "come on?
You will see -that more mfgrs are designing new engines for use with cans
I think even one of the US mfgrs notes that his newest efforts are designed to use em -
This business of a " stock muffler" --is very misleading .
Stock? by what standards?

wiggles

I can vouch for Bolly props. Am running a 19/11 3 blade on my ZDZ 50 and the vertical on a 14 pound plane is ballistic. Pulled 7100 new. Muffler is home made, couldn't afford a bought one.

Kris^

My Feedback: (1)

Dick, we bothknow the "altitude compensation" is afallacy, since the props also provide less drag at altitude. Rpm numbers are pretty close between altitudes up to about 6000 feet usually, depending on the efficiency and scavenging of the exhaust system. This is why a PIPED motor at altitude spins like crazy and has a better "boost" of power over a piped engine at sea level, when compared to "stock" mufflers.

That's old news.

"Stock" means available from the manufacturer. and I'll guarantee that the BME "mufflers" are nothing more than glorified exhaust diverters, so there is no "boost" there. DA recommends their "stock" muffler because the motor and muffler were matched for best power. What's to keep ZDZ from doign the same thing, or Bisson from doing it, for that matter?

Fact is, the DA50, even with the WORST muffler for it, is much stronger than anything we have seen published for the ZDZ50 (there was a thread here on RCU not long ago "DA50 is here" that addressed this very subject)

Of course, some "gurus" are gonna start playing with pipes and changing carburetors and touching the ports and inlet disk, and suddenly every ZDZ50 out there will be as strong as a 60-80 cc motor. Happens every time.

Flyfalcons

Bambulas are also well known for not turning high rpms. A 20-10 Bambula swinging about the same RPM as a 22-10 Menz or Mejzlik is not out of line.

rmh

I am not trying to be defensive - but youmay not had first hand experience with power losses from running engines at higher elevations.
T/F?
The Stock for ZDZ IS a system which is very quiet - they sell these engines in Europe -where quiet is a must.
Pehaps they could do a 50 cc setup , specifically for use with in cowl mufflers - AND more noise.
Their other engines 40-60 80 all run quite well (nothing like the piped setups ) on smaller mufflers

As for speculative results with other mufflers - I have found that speculation is pretty risky -for accuracy.
The "thread" on the DA 50 is simply hearsay -to me - tho I do know a bit about the background developement on that engine--
It is a very good engine !
It also has a cantilever crank- and rear intake -- something that got only condemnation from many - for some time- goes to show that you can't argue with successful design concepts.
I sure don't see why pipes should be shunned as some "unfair advantage"-- You lost me on that.
The carb mods I have done , have simply been to pick up bone stock Walbros - which are available in the USA -and bolt em on - In a couple of instances - I had to make a pressure port tap -
So far all of my engines have only had one BIG modification -- I run em in, in a series of fast slow and cool down cycles - till they "feel good" and are stable at full revs.
Ask anyone who has seen em .

I also use kinda oily fuel - -maybe not the best -but it sure works for me - --plain ol mid octane gasoline and mixed at 40 -1 with Pennsoil two stroke air cooled - then Redline Racing Two stoke -
I would not touch the ports on a bet - they don't need it - and I would not risk messing up the bore -which is Nikosil-
As for power on the pipe? -The 50 is really quite excellent .

h82crash

Altitude may be a handicap but I agree with the folks about the prop. Pro Zingers spin like heck and go nowhere. My Pro zinger doesn't look like a paint stirrer but that is all it's good for. Standard Master Airscrew woods pull much better and those aren't near as good as a Menz or Mezjlik.

Striker

For some extra clarification, please read this month's RCM Clearence Lee's review on the ZDZ 50. It was all glory according to him. I do not know why people bash other manufacturers because they own a different brand of engine. The DA's are great, the ZDZ's are great and so is the OS 46 FX. All these engines are good in its class. Another thing, engine ratings should never be based on TOC champions. I have and I am a lover of BMW's, and though the last two Formula 1 races (fastest car race in the world) have seen BMW come 1,2 twice, I still think Mercedes Benz, VW, Audi and Geo Metros are good cars.




Do not say apples are bad if you only eat oranges.
One man's meat can be a next man's poison.

Big_Bird

My Feedback: (1)

You guys sure did give a lot of good advice but it looks like you ran Goldie off. He hasn't reported back since his first post two months ago.

rmh

Clarance Lee told the story right -
The missing part was that he did not have better props and different exhaust setups to try - this is NOT a poke at Clarance Lee!
The guys who pass and moan about the power on big props -are using restrictive exhaust ststems
Frankly -the typical user in the USA uses a far more restrictive system than those used overseas.
I thought my 50 was great - then heard the tales of low power - In that I don't use the little in cowl cans - I did not know there was a problem!
especially on any tuned setup - the engine ran like a charm.
In all of the reported rpms I have read on any of the new 50's - the readings are right in line with what I got on the MenzS 22x8 and 22x10 props - which were the only ones I personally used - I saw none better --
I did run others engines on in cowl mufflers and they were down on power - in comparison.

shenion

ZDZ-40 here with bisson muffler here. Amazing engine.

Had a home made noisy muffler and had amazing power (Bisson back ordered.) Installed the Bisson an had a considerable power loss.

I heard a tip. Cut 1/2" off the pipes. The Bissons have restrictors at the end of the tubes. This apparently is to meet some of the strict noise requirements in Europe. After change, most of the power is restored an it is still quite quiet.

Have used Dynathrust, Pro Zinger, Master Airscrew, and Top Flight propsso far; all with significantly different results. Will probably move up to Menz as had best results on it on my G-62.