I am posting this for another guy. He is looking for an 80cc engine for use on a Hangar 9 SUK. With some detail, please explain what engine you think is best and why......

if possible compare engine to engine details.....

Thank you

I am saying the ZDZ 80 single is the route he wants to go, but he is worried about vibration.

What option?
other than the ZDZ80 - what else weighs in at 4.25 lbs and pulls as well as most 100's ?
Seriously
As for vibes - the 80 single has a light vibe at 3000 rpm -then any further vibes are due to prop/ spinner airframe etc..
The 3000 rpm vibe is a characteristic of any single -
Some may scoff - but if there is another 80 which competes favorably - I would like to know --

I agree, there is no other 80 that comes even close. BUT I do want to hear ALL COMMENTS on all the others as well

zdz80 on my H9 Sukhoi vid

The only thing better would be a 100twin! 72 flights on mine in the last 6mo not one problem.

The zdz 80 is great for scale war planes. The engine is like a light switch, on or off. It has no mid range for any kind of 3D. And it doesn't get close to most 100cc. If you want something with power, go with the 3W 75. It will out pull the zdz no problem plus it has that 3W torque that 3D pilots love.

I disagree, its a great engine, great throttle response, and swings the same size prop as some twins,(no, it does not make the same power, but is close), and costs half as much. Mine has good midrange IMO. You must not have had or flown one.

Yeah, I've seen the 3W75i go as well as the ZDZ 80. The 3W is a nice engine but doesn't have the power of the ZDZ. A nice engine for warbirds is the GT-80 because it is very smooth and relatively quiet too. Doesn't make as much thrust as a ZDZ or 3W 75i but is fairly compact and easy to run.

Sparticgus


First of all WELCOME to RCUniverse.

You will find that there are alot of people here and some with a great deal of knowledge. Due to the fact that you are new, in a thread like this one most people are going to need a little more info from you for YOUR WORD to have much meaning. To simply show up and state something such as you did, without an sort of back ground knowledge of you, it is hard to take your word for what it is........

What kind of GIANT SCALE knowledge do you have?
What engines have you owned?
What engines have you had the opportunity to fly and really get to know?

Give us some factual data to support what you have stated.

what is 3W torque?
anything like Thunderbird styling?
No offence - just musing -

First of all, sorry to have come off sounding so crude at before. Let’s start with me. I am a good friend of the guys at Aeroworks and with that am good friends with many top-notch IMAC pilots, including Chip. I have owned a few 50cc size airplanes and have flown everything else. That includes all the engines that have been discussed here. I flew the AW 31% 540T with both a 3W 75 and a zdz 80 along with a H9 Cap with the zdz 80. My impression was that the zdz was a top end engine. Powerful? Yes, but torquey? Not really. As compared to the 3W with has ungodly torque and a high top end. This is at least my preference for torque rolls and hanging and such. Not to say that this is right. The bad thing is that both engines shake like crazy. The 3W more so than the zdz. But after all, they are huge single cylinder engines. After flying those zdzs, I was very unimpressed. They have good top end power but nothing in the mid range. Therefore, that is why I recommend the 3W hands down.

And 3W torque is when you can have the airplane idling on the ground, punch the throttle, and have the left wing tip almost hit the ground!

That is what I call torque!

In terms of price and power I would go with the ZDZ. I think when comparing 2 engines you have to take in alot of factors such as prop choice and altitude (where you fly), just to name a few. I'm not a 3d pilot but the ZDZ has plenty of power to pull a 26lb plane upwards indefinetly. If the ZDZ is properly mounted on a stiff motorbox the vibrations are minimal. But again alot will have to do with the way the plane is constructed and the installation.
I should add that everyone is entitled to his opinion and personal preference. I think 3w are great engines(I have a 3w-240) but I would pick ZDZ-80 again if I was outfitting a 35% plane. Even if I was looking at the 150cc class the ZDZ-160 would get serious consideration. I just have had no problems from mine and like the service that I get from RC Showcase.

The low end "torque" of the 3 w may be nothing more than a well setup carburetor.
Torque curves on these are really tough to guess and for the most part - useless.
Throttle response however is VERY important.
aircraft engine loads increase in a non linear fashion-- which means that the off the line torque -such as a passenger car or street bike needs - is not required .
what is needed is simply max power output -on prop used .
swapping carbs around on engines changes response -in a large fashion.
both Tillotson and Walbro have more little redrilled permutations of basic designs -- thanyou can imagine.
This is not a put down on 3W - I like em.