Neo gold

Ok guys i'm either going to buy this engine for the 80" Nemesis or a DLE30cc....what makes the russian engine any better than the cheap chinese marvel?..
Also im not hearing any good news on the later light-weight vers of this critically acclaimed engine!?....
Why does it cost twice as much?..
Thanks

pe reivers

Russian? The Czechs love Russians like you do, and they even have more reason to.

blikseme300

My Feedback: (118)

ZDZ is not Russian, it is Czech. See them here: http://www.zdz-modelmotor.cz/

The Chinese engines, such as DLE, are not bad but are not in the same league as ZDZ.

Bliksem

hanko

I understand they are finicky starting.

ahicks

My Feedback: (2)

I've wondered about the same thing. Info above leaves me wondering. This opinion is based on what criteria? Power to weight ratio? Ability to swing a larger prop? Easier starting? Idles lower? WHAT?

If it's superior metallurgy or higher quality bearings, I'm good with what DLE offers, especially considering cost. I won't likely wear either one out with the amount of flying I do. I do like the ZDZ rear exhaust offering. Not sure why it's not used more often.

Tired Old Man

My Feedback: (1)

ZDZ makes a very good engine. They take well to tuned pipes and deliver a very long life of high performance. They use an induction system (rotary valve) that does not wear out or float with elevated RPM. Machine work is extremely good, along with the other engine components. ZDZ are not hard to start, but require the user to know something about an engine. They prefer to start wet.

Yes, you pay more for a ZDZ, and a few other engine brands. If you are satisfied with mediocrity or slightly above average then the cheaper engines are for you. If you want superior performance and life cycle you step up. It's that easy to understand. It gets real old reading people state they lack comprehension why some products costs more. If they ever used them they would understand and know. Performance isn't about having the cheapest price. A KIA will get you there but a Jimmy will do it in style while pulling your boat too.

captinjohn

Yup...my 1985 Jimmy done all that...now my son-in-law uses it as a wood hawler. I gave it too my Grandson & his Dad took it over. The engine will strart "first piston up" ...faster than a computer rigged engine. A computer has to read all thr sensors first ! sure did love that Old Jimmy....Amen

rstearman

My Feedback: (185)

I have a ZDZ 40. Never had any starting issues, It fires right up and runs great every time.

Neo gold

Well, costing more does not necessarily mean they are any better....take a look at the saito petrol engines...i fly very often & a.m. to dusk is the norm for me..
Cheaper engines are getting very close in the quality stakes now...& do what the dearer engines do & then some.
Properly looked after last for years...i have only ever worn out bearings in my 'cheap' dle & crrc engines...they still operate perfectly.

Tired Old Man

My Feedback: (1)

The average user of cheap gas engines can't even figure out how to get around the idle set screw on a carb. They don't know the difference between great performance and excellent performance. They have no concept of engine longevity and don't understand the concept of cost amortization. They can't mentally relate to the relationships of props to weight, airframe type, flying style, to exhaust tuning, etc. They don't recognize that "best performance" doesn't come out of a box and bolt onto the plane with no further need of user involvement.

For them a great engine serves no purpose. Whatever they have will hit the ground within a couple weeks of purchase anyway, and then they'll send it back for "customer service". If they are looking for cheap then any amount of qualifying why a more expensive brand is better will serve no purpose. They'll buy the cheapest one anyway.

Antique

My Feedback: (4)

rstearman

My Feedback: (185)

Cheaper engines are not that much less money than ZDZ engines. The standard ZDZ 40 is only $10 more then the DLE 55 and they offer 4 different types.
In the long run a ZDZ ends up costing less if your having to replace the bearings in the cheap engines Unless the new cheap bearings where only 8-9 dollar, or you can buy quality bearings for 25-30 dollars. Wait a minute: 8-25+10+T, oh never mind

All that I'm saying is; It is just like most anything else, You can buy quality performance stuff that last and when it does need work done on it, it's worth having repaired. Or you can buy stuff that when it's time to have it fixed the guy at the shop tells you it's not worth fixing and throws out in the dumpster overflowing in the back.

ahicks

My Feedback: (2)

OK, the OP asked for justification regarding the extra expense to purchase a ZDZ. I'm curious as well, but all I've seen above is opinion, with no solid criteria to back it up? OK it's a great engine, but why? If it's that great, this should be a no brainer to anyone that's familiar with them, right? Yes, it's got a rotary valve, and rotary valves are more stable at high rpm. So what, how well does that technology work in this application? Would it be turning fast enough to make any difference mounted in my sport plane? Does it idle better, turn bigger props, have a broader powerband, what? All else being equal, let's say in a sport plane turning a 6 or 8 pitch prop, what would you expect to see comparing a ZDZ 40 (not the F3A version) vs. a DLE 30 in a shoot out?

It starts easily - is this by hand or with an electric starter? Would starting be comparable to what I might expect from a DLE?

T.O.M. please park the condescending attitude long enough to share your experience with this engine. It's not necessary, and all the non relevant info really pretty distracting when trying to carry on an intelligent discussion. Thanks,

Tired Old Man

My Feedback: (1)

Please don't err in confusing the truth with condecension. It's a grave mistake. I get paid real good money for what are often propulsion "opinions", often backed up with data obtained from solid research, but still "opinions". If you want data and plot figures to go with facts and opinion, you can pay for it. I'm not giving them to anyone for free, or fee, because I would have to retire and renounce citizenship within minutes of doing so. You can't have everything for free.

Rotary valves are vastly superior to reeds at any RPM above 2500. They do not float or remain open, and manage to provide nearly exactly the correct amount of fuel and air for each combustion cycle. They permit the use of using critically tuned exhaust systems, enabling the development of peak engine efficiency and power for the same reasons. The copy engines will fall flat on their faces long before reaching the RPM an engine designed around performance will attain. With reeds, even the best reeds, which Chinese engines do not use, have short comings and limitations that most do not recognize.

Quality in fit and finish generates higher performance levels, and equates to greater longevity. Hopefully that's easy to understand. When you can pull a new engine off the shelf and obtain 97% of it's potential output on the second run beats the daylights out of waiting a couple years for an engine to "break in".

Engineering that went into using the right size and type of bearings contribute to providing higher performance. The "wrong" bearings can cost several hundred RPM of ourput. Bearing alignment contributes to cooler running engines and better RPM, not to mention longevity. Port sizes, timing, and angles improve or degrade performance, and determine how much performance will be available.

Piston top shape, combustion chamber shape, squish band and angle, spark plug location and angle, all go into making a true performance product. Just grabbing a piston and cylinder out of a spare parts catalog does not make for performance. It simply provides parts for an engine that runs to satisfactory levels. Much of the above is what makes a ZDZ one of the superior engines on the market, generating a higher selling price. None of this factors in the value of the Euro to the Dollar.

When you compare a Mecedes or BMW to a Ford or Chevy you know going in the door which is going to cost more and you recognize the engineering and quality of the high priced autos are superior to the lower priced ones. Yet nobody tries to negotiate the prices of the high end autos down to those of the domestic brands. Why? because they KNOW which are higher performing products. It's the same relationship with our itty bitty gassers. Go try to buy a Shindawa or Husky (for example) engine for the price of a comparably sized Chinese copy. It ain't gonna happen because Shindawa and Husky KNOW they have a better product and KNOW you won't have to do anything to fix it for a very long time.

rstearman

My Feedback: (185)

It starts easily - is this by hand or with an electric starter? Would starting be comparable to what I might expect from a DLE?

Regarding starting easily. My ZDZ engine starts by hand with out issue even after sitting for a year.

a ZDZ 40 (not the F3A version) vs. a DLE 30 in a shoot out

I use a 20/8 to a 20/12 prop on my ZDZ 40, I don't have a DLE 30 but I believe most guys are using 18/8, same prop I use on my 3w24

A shoot out does not show the total value of an engine, you have to take in account the quality of the product as mentioned by T.O.M. above..
Here's an example that comes to mind, My neighbors KIA Sorento might out run my wife's X5 in 0-60 run, but there is certainly no comparing in the two.

AJsToyz

Pat,

Do ZDZ's normally have a vibration to them? I had a 40RE that ran very well but seemed to not run as smooth as my Brison 2.4. I would like to have a Taurus in that class but I would have to watch for a used one.

Andy

Tired Old Man

My Feedback: (1)

That comes down to counter balance issues experienced with a single cylinder engine, some are better than others, and the fact that a rear induction, rotary valve engine is going to be missing a rear bearing. Can't put a bearing in the middle of the induction path. Brison did run a little smoother because of the cylinder port induction, where the Taurus runs smoother still because of that rear bearing. It's all a trade off with something.

At higher RPM the vibration isn't a problem because of time spent in position. The harmonics are not possible because of rotational speed.

For rstearman, the ability to swing a larger prop equates to greater torque. If the engine can't swing the larger prop it doesn't have the torque of the engine that can. However, I think a comparison between a 30cc engine to a 40cc engine is a bit of a mismatch and could never be a fair comparison. If ZDZ had made a 30 we would have a fair horse race. A fair race for the ZDZ would be found with an MVVS. A fair race for the DLE 30 is the 3w 28i. Power wise pretty close and for the average user the DLE would be the best fit, unless, that user needed to haul more weight or fly using an engine that would last 800-1,000+ hours. Then the 3w wins.

For qualifying a purchase decision, if I was to have a choice of buying a relatively new ZDZ 40 for only a few bucks more than a DLE 30 the decision is clear. It goes to the ZDZ. If I didn't need all the ZDZ had to offer in power, didn't fly but an "average" amount of time every year, and was on a limited budget, the choice would be the DLE. Again, we're back to tradeoffs in one area or another. Pick your poison.

The ZDZ will start by hand as easy as any other engine if the user understands the engine and gets a little more fuel to it before expecting it to start. A couple extra flips during the choke process is all it takes.

mrbigg

My Feedback: (21)

Rotary valve engines are so much smoother in the throttle response department. Smoother midrange also. I'll take my ZDZ engines over any brand, any day of the week. The smooth throttle response is one reason, the quality is the other. Now if DA or BME would switch to rotary valves, I'd consider them. I own four and only one was bought brand new. I do own a cheapo SV26cc engine and it has been good to me, but it is not even in the same league as the ZDZ quality wise.

ahicks

My Feedback: (2)

Awesome. That's the kind of answer I was after. I know you can supply this kind of info, but sometimes asking the right question to motivate you to do that is difficult. Thank you.

AJsToyz

Thank you Pat, that answers a few questions.

Andy

Tired Old Man

My Feedback: (1)

ahicks,

Yes, I can provide those kinds of answers but you have to admit that the vast majority of people will request engineering and performance information but ulitmately buy the cheapest thing they can find in an online import catalog, or run to Tower for their "high performance" wares. Their questions waste the time of everyone that troubles themselves to resond to the questions. I prefer to put reality on the table first.

People don't seem to understand that quality engineering and machine work don't come cheap. A good engine design requires a year of more computer work befoe it can make it to the first article stage. From there it goes thorugh evaluation testing to determine what changes will be required. Then it goes to re-design. You can have three or more years in coming up with a new engine design and hundreds of thousands of dollars in development costs. Name one Chinese engine that is a new design, one that does not generally incorporte parts and design copied from one of the quality engine manufacturers found in the U.S. or Eurpoe. There are NONE.

You have a few people knocking down $100k+ a year designing a product, toss in a shop full of real high end 4 or 5 axis CNC machines, tools to use in them, people that know how to use them, and complete each machine process correctly with the right tools. Now add better base metals, precision cylinder casting, precision ground cranks, and you have an engine that HAS to cost more than some pile of parts that were grabbed off the shelf from an after market spare parts jobber. Casting a cheap case to accept those parts is relatively easy but they still get it wrong. One truly good cylinder costs more than what most of the 15cc and 20cc engines sell for, even when buying 50 at a time.

Just because somebody working for minimum wage or one that has financially leveraged themselves up to their neck can't afford a better engine does not mean the high end manufacturers should lower their prices. They don't need to. Those that appreciate, require, and demand high quality and performance keep those doors open and profitable. The high quality engines don't need to be sold at prices equal or less than their actual cost. 20cc and 30cc class modelers are not typically among that group.

There's a reason you don't find Chinese engines on UAV's. Everyone has already learned you can't bet your life on one. If they make a high performance, high quality engine it has yet to be seen outside of their country.

Captain Terrific

My Feedback: (2)

Where can I purchase a ZDZ 40RE for an F3A style plane? Troybuilt does not have this engine listed. I will contact them to see if they can get it. I'd like to know if there are other resources though. Thanks,

Dave

AJsToyz

Dave ,

I went to the ZDZ website and it looks like the only single cylinder engine listed is a 90. Looks like you will need to make a few phone calls or emails. I did see a side exhaust 40 at the AMR website but that's about all I could find.

http://www.zdz.cz/en/gas-engines/

Andy

Captain Terrific

My Feedback: (2)

Thanks Andy,

I should have checked that first. I'm looking for an engine for a Top Model Aggressor. http://www.espritmodel.com/aggressor-arf-special.aspx
I was planning on a DLE 35 rear exhaust but I don't think will be enough. Maybe a 55. I'll wait till it arrives and test fit a DA60 I have. If it fits I'll probably go with the DLE. The DA is earmarked for another plane. Thanks again,

Dave

MTK

Dave,

I tried to like the ZDZ40 F3A. I purchased it some 6 years ago when it was selling really cheap at $550 (compared to a YS). I built a soft mount for it and got an ESComposites 40G pipefor it. It seemed to run okay turning a ZDZ 20x10 wood prop. Eventually I put it into an EF Extra 78" and ran it for at least an hour.....maybe 5 tanks. I was disappointed in its performance in the air with the 40G pipe. But the engine was nowhere near broken in. I took it out of the plane in favor of a DLE55. The DLE55 on the ESComposites 55G pipe is an amazing little powerplant. Coupled with the Mezjlik 20x12 3 blade prop and my soft mount, it is electric like quiet with terrific power and field manners. I've got this combo going into my new Pattern model

Later, I've played with the SAP30 cc, the PTE36R, Mintor 38cc, OS GT33, and am currently in process of evaluating the DLE35RA. Of these, the Mintor 38cc ran similarly to the ZDZ40, a bit anemic for Pattern type aerobatics. The SAP was very powerful but needed to rev up to develop its power. Not exactly ideal.

The PTE36R is decent powerwise. Except the fit is suspect. I had to take it apart a couple times to refinish the reed cage and refit the reeds, seal leaks, etc. Decent field manners, good power output that's really fine for sport flying, etc etc.

The OS GT33 so far is king of the hill in this size range, from 30cc to 40cc. It has the most power and torque in the class and swings the same props as a YS175 at higher rpm. In fact, I just got a 21x10 WPN to play with on the 33. It hauls an 11# pattern model around with lots of power to spare; the only time I go above half throttle is when I go up. My engine did have an early problem and needed to be returned to Hobby Services for repair, but has been absolutely flawless since. Of the many that fly this engine, mine was the only one I've heard of that had a problem.

The DLE35RA is next on the experimental series. Spring is right around the corner. I offer you this info since I've donea bunch ofexperiments already. I know what works and what doesn't work as well

Let me suggestrather than the ZDZ40,get the OS GT33. It is more powerful and weighs a lot less, and is much more available. Hatori makes a very nice back to center header and Ed Skorepa (ES Composites)has an outstanding pipe in his 40G. I have made a video on Utube of the set-up.