DA85 on pipe! Results please.

[dbcaster]

	Quote: Originally Posted by BoneDoc
	hmm... should Just get the 100L with stock mufflers then? Comparing it to KS 1090, then price difference ain't going to be much.

That is my feeling. You also don't need to cut up the fuse to fit the pipe in. If you need to run cans on the 100 then the advantage would go back to the 85. With the 85 and the pipe there is the cool factor though.

[BoneDoc]

But also, you're avoiding the spine-tingling vibration of a single cylinder 85cc piston .

[ejohn18]

Actually this engine is smooth once she's all tuned in.

Eddy Johnson
www.3dflying.com

[BoneDoc]

For those who have had BOTH DA100 and DA85, how much more vibration is there with the 85?

[Flatlandman]

My 85 didnt have much shake at all. My 100 might be slightly better but not enough for me to talk about. Balance your prop and tune the engine correctly from the first tank and every time it needs a tweak tweak it and the 85 or the 100 will be just fine. On the 85 i ran a 27x10th mejzlick from first flip and i had to balance it because it was slightly off. Same prop or larger on the 100 with almost identical results as far as shake go.

No tuned pipe on the 85 it was a pitts muffler

[BoneDoc]

Do you prefer the 85 then over the 100?

[Flatlandman]

I prefer the 85 on smaller planes 24 and under and the 100 on 25 pounds and up.

[BoneDoc]

If they put out the same power, why not 85 on the bigger planes as well?

[dbcaster]

The only way the 85 puts out the same top rpm is with a pipe. With the 1090 the weight is close to the same so personally I don't see any advantage to using the 85 in a big plane. After running both setups on the same plane I don't think the 85 had the same power as the 100 even with the pipe. Yes the top rpms are the same but the 100 has more torque. I felt the 85 would fade a bit more on an upline than the 100. I my opinion the 100 is smoother and has a more managable power ban for 3D. Again this is all just my opinion but I think most people that have used both engines prefer the 100.

[Flatlandman]

	Quote: Originally Posted by BoneDoc
	If they put out the same power, why not 85 on the bigger planes as well?

They dont put out the same power. IMO its not that close either.

[sprice50]

	Quote: Originally Posted by ejohn18
	I don't have a Mej but I have a Vess 27B I can do some test on. Eddy

We have to compare to Reza test with the RE3 so need to compare apples to apples.

I ran the 27B on mine and got 100 rpm less than the Mej 28x10! Noiser as well. The Mej was all round better for flying.

[sprice50]

	Quote: Originally Posted by Flatlandman
	They dont put out the same power. IMO its not that close either.

Hang on though.... you weren't running a pipe. They are same power if the DA85 is piped.

Ultimately, having a 85 just gives more flexibility if you think you may ever want a 33% size vs 35%.

Otherwise, the 100 makes sense for 35%

[Royster]

	Quote: Originally Posted by BoneDoc
	For those who have had BOTH DA100 and DA85, how much more vibration is there with the 85?

Bottom line: depends on the airframe.
As someone said to me, if you bolt the 85 to a brick wall it will come across as the smoothest motor in the world!
I have one in a wild hare sukhoi and a friend has one in a CompARF 260 and his has less vibration than mine ( or at lest seems like it does)

[meloni.racing]

I agree whit royster, the stiffness of the motorbox is the key point of the vibration, specially in the BIG single..

I have been running the DA85 in a Staudacker 600 whit a lightened motorbox for some time whit a noticable vibration around 3000 rpm...very normal for a single. Then I saw a stress crack in the motorbox and I decide to beef up the entire motorbox using light ply.... now the plane is just 3 OZ heavyer (was tailheavy anyway.:-) ) and the engine shakes a lot less, almost like any twin......

[BoneDoc]

So then, we're back to

"If you're going to use cans on the 100, the go for 85 on 1090"

"If you're going to use standard muffler, then the 85 with KS 1090 offers no real advantage"??