Da-85 - Actual Field Results

[krayzc]

AirborneSgt,

I have never owned a DA; however, I am quickly loving how smooth this one is running. I am def. feeling this Cap. The DA is sure making me come to terms with DA power. This Cap is so light it's so funny to see how fast I can go straight up. I must say i am getting hooked on that part. I did a rolling elevator/harrier with the bird today, this is the 1st 3d thing i have really did besides do a 2-4 sec. hover to see how easy it holds. The motor is so smooth the plane sits so still at idle. I took my BG Ultimate out today with a BME 111 in there and only flew it for a couple of minutes as it was getting pretty dark since i did so much time on the cap. Since I had put the Ultimate together I needed to fly it some lol. I also have a 27A Vess that i need to see what kind of RPM I can get on going up one inch. I may pick up somemore down line braking.....

also to lose the extra 4-7 oz that a twin muffer weighs along with the weight already saved from using a single I am hooked on the 85 for that reason. If my Ultimate did not already a light weight motor I would def go this route over a twin. My BME 111 is swinging a 26 x 10 Mejzlik at 6900 and a carbon fiber prop is easier to spin if you ask me and this DA is swinging a piece of wood like it's kewl......

Also with a lineer mix on the throttle my Cap is pretty fast at 1/2 throttle. I can def fly IMAC by only using 3/4 throttle again this is with a lineer throttle mix and not the usually come on hard by 1/4 throttle....

[airborneSGT]

Anyone have setup pics of this engine with a CF or regular tuned pipe?

[chrisbchips]

Hey airborneSGT,

I have actualy been flying a DA85 in a compsite-ARF 2.6m (35%) extra 260 for quite a while now, and it has plenty of performance, and with the lightweight it makes it an absolute freestyle animal!!

[RustyTumbles]

	Quote: Originally Posted by chrisbchips
	Hey airborneSGT, I have actualy been flying a DA85 in a compsite-ARF 2.6m (35%) extra 260 for quite a while now, and it has plenty of performance, and with the lightweight it makes it an absolute freestyle animal!!

Hi chris,

I heard a few weeks ago that the header pipe you used on the BMB can was to short, which was causing a power loss of around 400rpm. Is that true? If so what is the ideal length on that canister?

[chrisbchips]

We are still testing config for ideal quiet setup – haven’t had a chance lately with Tucson looming to play too much with header lengths etc – had to concentrate on practice and the BMB/header/ prop combination that we ran at the DA Challenge has been adequate leading in Tucson.

[RustyTumbles]

Thanks chrisby. I have my motor mounted so I can start to work out how much room I've got to work with and where to put everything.

[rdb127]

	Quote: Originally Posted by airborneSGT
	Anyone have setup pics of this engine with a CF or regular tuned pipe?

I'd like to know who makes a CF pipe for this size motor?

Richard

[Flyinrazrback]

There is not a CF pipe for this size that I know of. ES composites makes them for up to 50cc, but not this large. Last I heard he had no plans on making one for 75-85cc engines, but hopefully that will change.

[Yakov]

	Quote: Originally Posted by krayzc
	Well the Da 85 is moving right along on the 2nd gallon now and getting 6810 when landing with a 26A Vess prop.

Krazy,

Are you using the JTEC high volume pitts muffler? How is the noise? What octane, 87?

Also are you using recomended breakin oil at 32:1 or did you go right to Amzoil Sabre at 100:1?

I bought an Airwild 26x10 NX and a 27x10NX but will not have data for another month till the plane is finished.

FYI you guys that tdon't think this engine can fly a 35%er... I have a freind who took his Da100 out and stuck the 85 in on a Slimline Pitss with a Vess 27A prop and it is outrageous. Flys the Carden Edge like it was a foamy. This guy only does 3D so he wants vertical punch and he says the airplane is better now then when the 100 wasin it.

One drawback...? ........... he might be able to rival Snapassoraus for noise.... man it rips with that Vess.

[krayzc]

Yakov,

I agree that this motor is not following the standard rules for power and vibration. It’s on the 2k + era and I love mine. I am running 32/1 Pennzoil on this and all my gas motors. The only difference is after they break in I go to a 50 to 1. I really think with today’s oil they are all very good we just pick and choose to feel good in our own minds. I have seen some pretty humble lawn mower motors just plugging along when the mower itself looks like its going to fall apart at anytime. Lol.
To get my latest tac reading a guy who has one of those Fromeco tach ask could I tach your motor when I landed the Cap. I am the only one at the field right now with a DA-85 so about 10 guys came over when I landed to witness the tach reading of 6810. I then said to them dam% the last time I tached the motor it was at 6550 hot. I have a linear mix on the throttle and this plane is pretty fast at ½ throttles and just a blazing glory on up lines at full throttle. I am still working out how much gas to give it do a large loop as far as when to give the gas and so forth. I love the power to weight ratio of this set up. When you think about the average non BME motor twin weights in around 6 pounds plus adding 4-7 oz per exhaust standard you can quickly drop a few pounds with this set up. I just put my planes together and what ever they weigh is what they weight and I fly and trim them out to my liking and never look back, however, this is def an eye opening with weight and power. I also hear people who don’t have this motor say it will never be as smooth as a twin and heck I own two other twins a 3w-150 and a BME-111 and this is one smooth beast. I find it’s just not good to get into those internet wastes your time debates on some RC topics or things in general life lol. We all have our ideas and opinions and its all good to me. Noise wise this is got to be my loudest plane. I have a DB meter but I have not put it on the plane to see what the specs are. 2 of my 4 gassers are running cans or a tune pipe so I can’t even put this in the same class with them as far as noise goes. My Bmeerrr and this DA both run mufflers of the non-can or pipe deal. I do have a 27A Vess that I bought for the Bmerrr, I will have to try it out as the gallons go further on the DA. I am on my 2nd gallon right now on the DA so I should be able to check it out soon especially now that it seems we have hit a colder streak vise those July and Aug 3 digits temps, man that was rough. Do you recall what find of numbers your friend is turning on that 27A Vess. I bolted that on my BMerrr when Keith rebuilt my 100 to make it a 111 and I recall getting under 6k more like 5700 or 5800. I removed it and put on a 26 x 10 Mejzlik to let the ol girl spin up and break in. I am getting 6900 on that prop up from about 6600 or so. I am on the 3rd gallon on that break in motor. The JTEC muffler I am using is the cheaper on I think it cost about 119 and they also make one that is higher price than this one. Great guys at JTEC and they are located right here in my area about 20 minutes away Al and I talked for about 10 minutes and he educated me on those mufflers to bad I forgot most of it lol. I would guess this is a 96-98 DP as comparing to my lower reading on my 3 blade set up on my 150 and a 23A vess on a T/pipe C/fiber EF Yak. The plane does sound like a Harley up in the air and again its my noisy plane gas wise. I think my DA manual calls for better than average gas; however, its only getting 87 or 89 octane gas. Well I have been known to be a talker I better end this so that I can break ranks and prove that I am not a talker……

[Barry Cazier]

It seems to me that all this discussion on RPM VS. prop size doesn't really mean much. Too me the more important number is "thrust". That way we can compare the thrust vs. the weight of the plane and estimate perormance via that way.

With that in mind...I read the whole thread and only saw one number posted and it seemed to be not totally accurate. He stated between 45-50lbs on his fish scale. I use a fish scale and think they are very accruate.

My DA85 is going on a SDYak 33% HP. I'm building the plane now and hope to have it done in less than a week. I'm using a MTW 110 canister (noise is a problem at my field, plus, I like quiet planes) I've had difficulity getting the header/canister to line up but think I have it ready now.

Anyone care to hazzard a guess about my thrust? I'll be turning a NX/TBM 26x10 prop and I'm at 4800' elevation.

I love the look of the engine but haven't even started it yet. Although I've got it mounted and should do a mild break in in a day or two.

Here's the real deal on the engine weight:
DA85 w/ spark plug and prop washer and bolts: 69.2 ozs
Ignition w/ (2) connectors" 4.2 ozs
Header pipe: 4.4 ozs
MTW TD 110 K canister: 11.4 ozs
Header/canister connector w/ (2) clamps: 2.0 ozs.

Total weight I'm putting in my plane: 91.2 ozs or 5lbs 11.2 ozs.

This is my first above 50cc plane. Does that weight seem good? Now...if someone can give me an estimate of thrust with this canister...I'll be good. I expect my plane to come in just under 22lbs.

Thanks
Barry

[airborneSGT]

Barry thats about 5 ounces lighter than a DA 100 with regular mufflers setup. You will have the benefit of being quieter with that setup though vs. the DA 100.

I think its a bummer no one wants to make CF tuned pipe for this size. If so then you would really be getting a signifcant weight savings without the noise!

[toprudder]

	Quote: Originally Posted by Barry Cazier
	It seems to me that all this discussion on RPM VS. prop size doesn't really mean much. Too me the more important number is "thrust". That way we can compare the thrust vs. the weight of the plane and estimate perormance via that way.

Thrust is one parameter. However, static thrust really may not mean much. Thrust will change drastically as the airspeed changes. You could put a really large diameter, low pitch prop on the plane and get tremendous static thrust, but not be able to fly the plane well since the low pitch would limit your airspeed. How much thrust at 10, 20, 30, 40mph would be useful data. Not easy to measure with just a fish scale.

Bob R.

[Barry Cazier]

I agree...but static thrust will give you an indication of pull out from a hover. The RPM doesn't really tell much in that area either. So...maybe post the RPM and the static thrust. On my 50cc planes I use a 8 pitch x 22". On the 85 I'm starting with a 26x10. That will give the plane a bit more speed. But at my altitude I'm always concerned about thrust. 22x8 is pretty good on my Edge and Yak though. It flys it fast enough for me, but I do mostly 3D aerobatics.

Thanks
Barry

[WangoTango]

My buddy Mike just left my house with his DA-85. He's going to put it on a Mick Reeves Spitfire. (110" span) He's pretty proud of this motor and is looking for a testbed. I told him to plan on one I have in my hangar and not to bother doing a bench running session. (Don't worry guys.... I'd hurt him bad if he tried!) His Spit is going to be a replica of a plane that belonged to a first love of his 87 year old Mum.(She's from England.) "Frank" died in combat at the controls of that Spit and he is trying to duplicate it from old photos. Ought to be a quick bird with that DA! Don't know his muffler choice yet.
WT