does 3d doen better with 4 sroke engine ?
 

I would to fly middle size model (90-160) for 3d/freestyle
should i use
1) 4 stroke engine which might be more complex/expensive but has more torque
2) stick with the 2 stroke which is simpler to run and mainly have more hp

does 3d doen better with 4 sroke engine ?
 

I think all you need is a quality engine, not one of those that suck air from everywhere so it does not run properly.

My own preference is for the 2-strokes; cheaper, easy to run, less maintenance and so on...

If money is not an issue, 4-strokes are very good choices as long as they are good quality. I just purchased a used YS 140 DZ (was really cheap) and LOVE the incredible throttle transition and power.

A 2-stroke is often about half the price of a 4-stroke of comparable power.

In my opinion, the aircraft has more to do with 3D than the engine, as long as it is powerful enough.

does 3d doen better with 4 sroke engine ?
 

Benefits of a 4 stroker:

1. the ability to swing a much larger prop producing more airflow and a larger prop area
2. uses less fuel which means you can use a smaller tank, less rtf weight
3. not near as noisy, keeps neighbors happy
4. way more torque at lower rpms, 2 strokes require much more rpms to power out.
5. lighter than some 2 strokes of same size.

Now as for a 2 stroker being easier to run that's just your opinion. They cost less yes but you get what you pay for.

As for maintenance on a 4 stroker, the only thing extra is periodically checking the valve clearance.

The aircraft may have more to do with 3D than the engine but with a good engine it makes 3D'n much more enjoyable and easier to perform.

does 3d doen better with 4 sroke engine ?
 

Just a question for you wreckrman2, do you think a 300$ 2-stroke is not a good choice over a 300$ 4-stroke? You said that you get what you pay for and to me that is perfectly true but my thinking is that less parts 2-strokers for the same overall price mean a higher quality engine.

As for your previous post, I mostly agree with you (I have a 650$ 4-stroke and see the incredible quality).

does 3d doen better with 4 sroke engine ?
 

Id go with 2-stroke. The RPMs are higher, and that makes for the engine not bogging down as much as a 4-stroke would. When you run a 4-stroke, you are going to have to run a very large low pitch prop, that is also swinging very slow. When you run a 2-stroke, you run a low pich but not quite as large of a diameter, yet you always have the power to pulll out without it bogging.

does 3d doen better with 4 sroke engine ?
 

You don't have to run a low pitch prop on a 4 stroker. In fact I run a 13x6 on my Saito 72 and it still has enough power to hover a 5lb plane. If you have to worry about your engine dying at lower rpms then you need to adjust the carb better and if your bogging down the engine then you've over propped it. A perfect example of this is all the guys the use the APC 12.25x3.75 props on a 40 size 2 stroker. That's over propping and it will bog down the engine because a 40 size 2 cycle isn't meant to swing a 12" prop. Remember the largest diameter, lowest pitch prop you can swing on an engine does NOT make it the best prop to use for 3D.

As for comparing a $300 2 stroke with a $300 4 stroke I highly doubt your comparing same size engines. Were talking Saito 100,120 or similar for a $300 4 stroker and I don't know of any 2 strokers in the equivalent size of 90-120 that cost $300. Maybe $225-230 but not $300.

4stroke larger prop
 

I have a question? Why does everyone seems to think that four strokes swing larger props and have more power. When the fact is 4 strokes produce a lot less power than 2strokes of the same size, this is evident when you look at any kit for any r/c plane, you will see that the kit will recommend a certain size 2 stroke and a larger size 4 stroke. For example a .40-46 size airplane will recommend a .60-.72 size four stroke engine. Sure a .72 size four stroke will spin a larger prop than a .46 2 stoke :mad: but lets compare apples to apples. Like a OS 91 fx and a saito .91 , its "plane" to see that the os will not only swing a bigger prop but it will also turn it faster. Personally I think people spend all the extra money on 4-strokes for some kind of status thing, I think they are a waste of money, and time. Especially considering that they require maintenance such as adjusting valves. Another myth I hear people bragging about four stroke is that they sound so "good" and more "realistic" . BALONEY :devious: . No engine that has a displacement of + or - 1 cu in is going to sound any where close to a 200+ cu in engine. Well thats my 2 cents.

Michael :D

does 3d doen better with 4 sroke engine ?
 

When most compare 2 strokes to 4 strokes they already know that there is a displacement difference. It's just common ground in this hobby. That is why your able to swing a larger prop and get more torque, not necessarily power, from the 4 strokers but even with the larger displacement the 4 strokers are as light or lighter in weight compared to the 2 strokes. As for the sound I don't care about realistic sounds but I do prefer the much quieter sounds of the 4 strokes. As for swinging a prop faster that doesn't mean it's better.

Look at it this way, 4 strokers produce the most power at low-mid rpms with alot of torque while 2 strokers produce the most power at high rpms with very little torque.

Now as for same displacements swinging larger props here is what I pulled from the OS and Saito websites:

OS91 (2 stroke) recommended props: 13x8-9
Saito 91 (4 stroke) recommended props: 12 x 8 - 15 x 6


I guess it all boils down to personal preferences, the needs of the airplane in comparison to how you want it to perform and of course your spending budget.

If I'm building a Morris profile that I want to 3D the hell out of then I go with a Saito 72. If I were building a Diamond Dust that I wanted to push 200+ mph I would indeed use a 2 stroke.

thanks ...
 

As i understood there is no definite question regarding 3d and the right engine.
it seems that different people has different ways and preferences for running 3d models.
in any case i noticed that as larger 3d model you are going to use you have less large 4 stroke engine options (os biggest 4 stroke engine is 120)

Am i right ?

thanks

does 3d doen better with 4 sroke engine ?
 

Your right... I may be wrong but I think the Saito 180 is about as large as they go but then you get into gas engines where 4 strokers are almost non existent.

does 3d doen better with 4 sroke engine ?
 

Wreckman is right. Each engine has it's pros and cons for certain applications. I use a 2 stroke if I want high revs and high speeds. I use 4 strokes when I want lots of torque, quiet operation, and slower speeds (Mainly aerobatic planse). If I build anything larger than your standard 100 size aircraft my first tought would be to go gas. Sometimes there are compromises and you'll go with something you normally wouldn't, but generally I follow those guidelines.

A lot of times I'll stick with 2 strokes because they are more economical, but if I was rich, I'd probably put a 4 stroke in almost everything. I much prefer slower aerobatic planes than I do those speed demons.

does 3d doen better with 4 sroke engine ?
 

Wreckrman as a owner of a .91 fx I can tell you that it can turn a lot larger variety of props than just a 13x8 - 9, Besides the load on a 13x9 is about the same as that of 15x6. Check out towers website and you will see some specifications on props ranging from a 13x6 to a 16x6 this is what tower has to say about the specs on the .91 fx.
Prop Size RPM
13x6 12,500
13x8 10,400 using a 13x8 prop,
13x10 9,500 Hobby Services tached this
14x6 10,900 engine at 11,300 rpm
14x8 9,500 6-24-99
14x10 8,400
15x6 10,200
15x8 8,100
16x6 8,300
WLG 10-16-98
ir/jl


And the whole thing about modelers already knowing that there is a displacement difference is only further proof of what I am saying is correct, pound per pound you'll get more overall performance at a lower price with a 2 stroke compared to a 4stroke. Another thing, 2 strokes work great in aerobatics. I have a 1/4 scale extra 330 that has an OS 1.60 fx and it will blow the socks of of any quarter scale using the saito 1.80. You just need to use the correct prop. I don't see any of the guys in the 1/4 scale 3d forums debating the saito vs os or saito vs moki. its mostly debates on os vs moki...2 stroke vs 2 stroke LONG LIVE
2 STROKES :boxing:

4 stroke more economical ????
 

I own a os 1.60 fx and a saito 1.80 and i will tell you that the four stroke is in absolutley no way more economical than a 2 stroke, it uses twice if not more fuel than the os. my 1.60 fx is swinging an apc 18x8 at 8900 rpms and the saito 1.80 is swinging a 17x8 at 7700 rpms.I personally ( and only my opinion ) will never buy a large 4 stroke again, i think they are a pain, not any more quiet ( my 1.60 with a bisson muffler is quieter than the saito ) and waaaaay more finicky. just my opinion.

does 3d doen better with 4 sroke engine ?
 

I have a question for you all. What is the real advantage of having more torque?

Personally, what I am looking for in an engine is THRUST and throttle transition (control). I don't see a real advantage of having a big prop. Big propped airplanes tend to roll with application of gas during landing when near stall speed.

When I torque roll, what I really need is thrust and control of it.

Maybe I am fool but I don't understand the advantage of higher torque.

Torque
 

The higher torque in the low to mid range means you can swing that larger prop without it bogging down. IT has the torque to speed it up for instant linear throttle response. That's why many people like 4 strokers for aerobatic planes.

does 3d doen better with 4 sroke engine ?
 

Larger props = more air over the tail at any given time.

Thats what you want for 3D.

does 3d doen better with 4 sroke engine ?
 

3D I like gas and 4s's,combat 2s's,anything else,what ever engine I have laying around,what ever turns you on then fly it,not that big a deal,this is for fun, my $.o23 worth,

does 3d doen better with 4 sroke engine ?
 

Looks like the 1.60fx swings a larger prop faster than the saito 1.80 so I guess it has more torque and moves more air, which equals better for 3d. 2 strokes the only way to go. :D

does 3d doen better with 4 sroke engine ?
 

Yes. You are right. I am selling all my 4's

does 3d doen better with 4 sroke engine ?
 

Morning Wayne, now that you've seen the light of your mistake on engines, if you'll pay for shipping and a small amount of cash, I'll take those worthless 4 strokes off your hands.Guess I'll have to store mine in the closet,do you think gasser's are also no good??

does 3d doen better with 4 sroke engine ?
 

For me the main difference is that 4s have more torque at low and mid RPM when you actually need it because at top RPM 2 and 4s will have almost the same (making the right comparison obviously), I run a 14x4W APC on a Magnum 91fs on my Diabolic and works like a dream great engine prop combination and this engine it's lighter than a OS 61 2 stroke that I still have on the box, but I'm using a larger prop easily , I do waterfalls almost at the same height, throttle response? not an issue it's as good as my YS120. I think it all comes to preferences and what really makes you happier depending on your abilities to set up the engines. P.D. I only use 20/20 fuel on four strokes.

does 3d doen better with 4 sroke engine ?
 

I'll just sent them to you at no charge.

Gassers?
I love my 2 cycle gassers in large planes for 3D.

does 3d doen better with 4 sroke engine ?
 

thanks, was afraid I was going to have to get rid of the gasser's for 2 srokes.

does 3d doen better with 4 sroke engine ?
 

Your Gasser is a two stroke... :p

does 3d doen better with 4 sroke engine ?
 

Yes I KNOW, WAS TRYING TO GET ANOTHER REPLY FROM PREVIOUS POST ABOUT 2S GLOW BEING THE BEST FOR EVERY THING,REALLY NEED TO GO FLY INSTEAD OF PLAYING WITH THIS MACHINE.