DA60 with MKS can, rear exit.
Falcon 24 x 9 cf. 6700rpm
Mej 24 x 8 EVO 2 7000 rpm.

Flying: Mej was slightly slower speed horizontal. Vertical was forever...slow and steady.
Vertical downlines were noticeably slower than with the Falcon. Better 'braking'.

Cool day, around 50F. Elevation 600 ft ASL.

DA215 @ 5850 rpm, 34 x 12, 80 mph at 3500 feet and 72 deg f, head temp 310

Originally Posted by Mithrandir

DA215 @ 5850 rpm, 34 x 12, 80 mph at 3500 feet and 72 deg f, head temp 310

so please post pictures!!! we want to see

I did some tuning on my ZDZ-140 today. The engine has 4,5 hours on it. Still spits a lot of black residue. I peaked the engine and turned back a bit. After that I got 6700 on the ground with Falcon 29x12 and KS 1080 pipes. The temperature was 22C, altitude 122 meters ASL, air pressure 1014 hPa and humidity 60-70%.

My flying buddies with ZDZs said that I can expect to have some 200 rpm more once the engine is completely broken in.

--kaboomski;

It takes about 15 HP and 11.23 kW at the shaft to turn a 29x12 6700 RPM. This is also about 37.6 kilos of thrust (82.9 lbs). The tip speed is a bit high though and in the zone where you'll loose a little efficiency (Mach 0.75).

A 30x12 will give you the same thrust at 6325 RPM and the 32x10, which was the prop we settled on with the DA-150 (Mejzlik), will deliver the same power and thrust at 6180. Not really any tip speed change so they all will rip.

Da100L w/hype pipes, falcon 28x9.5 =6780 static and 7320 unloaded

DA100L
stock compact mufflers
Shell 93 octane (unleaded w/std 10% ethanol), 40:1 Redline and Sta-Bil
20' ASL
92 degrees F, >80% RH
Mejzlik 28x10
6475 rpm ground
7440 peak rpm in the air via telemetry, dragging a 36% PAU Edge 540T

Just started my new DLE 55 RA for the first time. Xoar 22x8 laminated prop, JTec pitts muffler, Tru turn Spinner, 90 octane pure gas (no ethanol) Stihl HP mixed at 40:1--- 7480 RPM on the ground.

I've been following this thread a long time and really learned a lot from the work of Pe and all the great test data Brad was posting years ago. But since Biff mentioned when this thread was started that understanding power expectations from motor/canister/muffler/prop combinations would come from real world result, I thought I'd post results from my latest "motor" project as well since electric power has become more popular than it has been in the past. We have an electric power thread on RCG and it has almost 1.3 million views so maybe someone here would benefit too.

A StinGR 3.33:1 Gear Reduction with custom wound Scorpion 5035 motors:

27x12L PT Carbon with a 515Kv on 44.4v = 6179 RPM
28x13 C2E Falcon with a 525Kv on 44.4v = 6300 RPM
28x12 Xoar PJN with a 540Kv on 44.4v = 6480 RPM
28x12 LF Mejzlik with a 460Kv on 51.8v (14S) = 6411 RPM

The gear reduction efficiency to the shaft with these props is 90.08% so for example the 6411 RPM with the 28x12 Mejzlik is 192A on 14S but the non-geared equivalent of 11.2 kW. A YGE 320A controller was used for this in a 105" Skywing Edge.

I also tested a 3-blade Xoar 24x10x3 PJI-E (199g) on a 515Kv motor at 44.4v because I'm thinking about a scale 3-blade on a 91" Extra or Edge. I got 6180 RPM and only 135A or the non-geared equivalent of about 152A and 6750W. It's developing the same energy at the shaft as a 27x10 of the same weight to the same RPM. It will pull about 44 lbs on the Ralala too and more when it cools down a little here.

3W 80Xi CS
26x12 Mejzlik
20cm header
AS Power canister
Stihl mix
6100rpm

A 26x12 (either TH or Evo) will develop about 7.17 BHP at the shaft. This is also about 46 lbs of thrust and a 69.3 mph pitch speed or the estimated level flight airspeed of 83.2 mph.

In comparison with other data posted here:

Originally Posted by Aeroplayin

A 26x12 (either TH or Evo) will develop about 7.17 BHP at the shaft. This is also about 46 lbs of thrust and a 69.3 mph pitch speed or the estimated level flight airspeed of 83.2 mph.

In comparison with other data posted here:

is this calculated data or measured?
I have pud data to PE's calc, there is a big diference between mejzlik props, and come out with 8,3HP and 21,5 static thrust

The first 7 columns are reported here in this thread over the years.

HP is at the shaft (BHP) and easy to calculate.

Static thrust is different than actual thrust values. The formula for Static gives us a result that is supposed to be used with the advance ratio to give us thrust in motion. It's virtually meaningless without advance ratio other than as a relative comparison.

I get a measure thrust of 21.5 lbs swinging my 20x8 to 7900 RPM.

There are a lot of online calcs that will give you about the same value as you see in the chart since thrust is a product of disk area and torque.

Pe used static thrust, which is:

=(((0.39269875) * ((Prop Diameter * 0.0254)^2) * air density in kg_m3) * Max Pitch Speed)

Pe and I were talking about prop load when he passed, but I've found through testing that pK is a variable, which makes sense when we consider the vectors involved in load and how they change with angular velocity and momentum.

With a 26x12, the pK is 1.0684. And if you use a torque constant in your calculations, the power at the shaft suggests a Tk value of 0.915.

So if you take these values to an online calculator, like this one, you can use 1.0684 for the pK field and 0.915 for the tK field, and along with the 26x12 specs and 6100 RPM you should get about 46 lbs.

I used my altitude and took a WAG at what the air temp would be in Slovenia.

Forgot to add that Watts-out and BHP are related through the following formulas:

Watts-out = (((prop length / 12)^4) * ((RPM / 1000)^3) * pK * (prop pitch / 12))

So (((26 / 12)^4) * ((6100 / 1000)^3) * 1.0684 *(12 / 12)) = 5344.3 Wo

5344.3 Wo / 745.7 = 7.17 BHP (brake horsepower at the shaft)

Originally Posted by Aeroplayin

Forgot to add that Watts-out and BHP are related through the following formulas:

Watts-out = (((prop length / 12)^4) * ((RPM / 1000)^3) * pK * (prop pitch / 12))

So (((26 / 12)^4) * ((6100 / 1000)^3) * 1.0684 *(12 / 12)) = 5344.3 Wo

5344.3 Wo / 745.7 = 7.17 BHP (brake horsepower at the shaft)

tnx for explainig, is a diference,