Da-85 - Actual Field Results

[madmax]

These samples were taken in Costa Mesa, California.

Weather conditions were sunny with a temperature was 75 degrees Fahrenheit and humidity of 61%. Altitude is approximately 31 feet above sea level (the sea is actually 1/4 mile away).

The motor is a -brand new- DA85 with approximately 3/4 gallon run through it. The muffler we are running is a Jtec in cowl pitts designed for the DA85. Per manufacturer instructions, we are running Amsoil 100:1 on 91 octane super unleaded, and if anyone cares, it was purchased at Mobile.

We *are not* running petroleum based break in oil.

Various props on the ground, cowl off. During the engine runs on each prop, the motor was cycled to full throttle, then to idle 3 times for approximately 5-10 seconds. In between prop changes, the motor was cooled off with a leaf blower until the cylinder head dropped below 100 degrees Fahrenheit.

RPM measurements were taken with an Eagle Tree hall sensor RPM pickup, calibrated and verified by an optical meter. Measurements will be posted in form of graphs and screen shots from the Eagle Tree flight logging application.

We have tested the following props (all in spec per manufacturer):

26x10 Mejlik
27x10TH (thin) Mejlik
27x12TH (thin) Mejlik
27x10 NX

Alrighty, before we start this thing, I want to put a big 'ol disclaimer on our results. These are our test results based on all of the conditions stated above, with our equipment and configuration. Results may vary. For all the motorheads out there in internetland who wish to challenge them, please spare us the drama, and feel free to post comparison results when the motor comes available.

This information is being posted as product information only, and we are doing our best to post accurate figures.

Next week when we come back from The FlyingGiants Huckfest in St. Louis, we will perform more flight tests. The numbers you are about to see are very impressive and far better than we initially imagined, and we feel the video which was posted yesterday is just a glimpse of what this motor is truly capable of. The motor has come to life with the new props we just received.

Check it out.

[madmax]

This is a screenshot of the Eagletree flight logging software. Data from the logging unit was downloaded between each prop test, and the logger was cleared for the next runup. The software is pretty sweet, and will log stick movements, head temp between our two sensor loops, battery voltage and altitude.


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[madmax]

Per our a good friend, Robert Vess's advice and feedback, we have opted to use Eagle Tree's hall effect sensor for RPM measurements. During our initial test of the system, the optical sensor read accurate, but was sensitive to direct light which caused "flutter" on our charts. This may have been because of the handy black and white paint work, but the other sensor seemed like a better way to go.

The RPM sensor was simply "piggy backed" on the side of DA's hall sensor with a clean path to the hub magnet, and tacked on with thick CA. This setup works great!

We have moved one of our temperature hoops to the top cooling fin for better readings. In the Eagle Tree software screeny above, the hoop closest to the spark plug is designated as "Tmp1".


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[madmax]

Okay, now to the data.

The first sample is from a Mejlik 27x12th. The results tested today were an exact match to the flights we tached this past weekend.

This prop was featured in our initial flight video along with the 27x10 NX.

Prop: Mejlik 27x12TH (thin)
Max RPM 5,882

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[madmax]

The next prop we tested was the 27x10 NX. This is a wood prop provided to us by Airwild Hobbies.

Prop: NX 27x10
MAX RPM 5,744

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[madmax]

Okay, here comes the zonker - these are the numbers you've been waiting for!

The next prop is a 27x10TH (thin) Mejlik. The prop was cracking on the ground, and the motor finally opened up! I mean really opened up. I can't wait to get the edge back up in the air to finally see what this motor is capable of.

Prop: Mejlik 27x10TH (thin)
Max RPM: 6,260

[madmax]

And finally, our last prop, the Mejlik 26x10. All I can say about this is, holy cow!

Prop: Mejlik 26x10
Max RPM: 6,423

[MikeC3D]

Max, Try a couple VESS props if you could please.....These things pull pretty hard.
27-A
27-B
Not sure if they have 26's
Also what about tuned pipes are you gonna try this also?

[krayzc]

they have a 26 and the streets say on any 80-85cc the 26A is the deal....

[B Rocka]

I might end up getting one of these for my Extra 330. But I'll for sure run a Vess prop!

Vess Props definitely perform the best!

[Bat Fastard]

This motor turns 200 RPMs more than my OLD style ZDZ 80 on a Mejzlik 26-10 and a VERY loud supersonic pitts muff.

BF

[krayzc]

what is the quiet set-up to run on the 85?